Tartary buckwheat and adzuki bean, which are classified as coarse grain, has attracted increasing attention as potential functional ingredient or food source because of their high levels of bioactive components and various health benefits.in vitro starch digestibility of instant powder which consists mainly of Tartary buckwheat and adzuki bean flour.This work investigated the effect of two different extrusion modes including individual extrusion and mixing extrusion on the phytochemical compositions, physicochemical properties and −1) were observed in the instant powder obtained with individual extrusion than in mixing extrusion  by logarithm-of-slope analysis. Moreover, two extrusion modes had no significant impact on the sensory quality of instant powder. Correlation analysis showed that the flavonoids were significantly correlated with physicochemical properties and starch digestibility of the instant powder.Compared to mixing extrusion, instant powder obtained with individual extrusion retained higher levels of protein, resistant starch, polyphenols, flavonoids and lower gelatinization degree and estimated glycemic index. The α-glucosidase inhibitory activity (35.45%) of the instant powder obtained with individual extrusion was stronger than that obtained with mixing extrusion (26.58%). Lower levels of digestibility (39.65%) and slower digestion rate coefficient (0.25 minThese findings suggest that the instant powder obtained with individual extrusion could be used as an ideal functional food resource with anti-diabetic potential. As awareness increases about consuming high-quality foods, it becomes necessary to seek cereal flour with better edible and health care value to produce instant powder. Cardiometabolic diseases such as diabetes and cardiovascular disease have caused a huge global health burden, at the same time, coarse grains consumption has been considered as a major factor in controlling heart metabolic diseases . Coarse Fagopyrum tataricum (L.) Gaench], which is a species of buckwheat, has attracted increasing attention from food scientists for its health effects over chronic diseases (Vigna angularis) is a kind of edible bean, which is one of the earliest crops in East Asia , which is to extrude Tartary buckwheat flour and adzuki bean flour individual, and then mix together with other ingredients . The other is called mixing extrusion (ME), which is to mix Tartary buckwheat flour and adzuki bean flour before extruding, and then mix with other ingredients . This study will provide theoretical basis for further development of instant coarse grain food and improvement of processing technology.We assumed that different extrusion treatments have different influences on the quality properties and starch digestibility of instant powder. Therefore, two processing modes were performed in this study to investigate their influence on phytochemical composition and properties, α-glucosidase inhibitory activity, sensory properties and 2.2.1.Tartary buckwheat, adzuki bean, walnut, wolfberry and xylitol were kindly provided by Ningxia Huantai Bio-Technology Co., Ltd . Standard reagents , α-glucosidase (100 U) and p-nitrophenyl-a-D-glucopyranoside (pNPG) were purchased from Shanghai Yuanye Bio-Technology Co., Ltd . Pepsin  and pancreatin enzyme  were purchased from Sigma Aldrich Co . The other chemicals and reagents used in this study were of analytical grade.2.2.o C, the feed moisture content (dry basis) was 14%, the feeding rate was 120 kg/h, and the screw speed 590 rpm. The detailed processing procedures are shown in 2.3.The compositions of different instant powder samples including moisture, protein, fat and ash were determined according to the methods of GB5009.5–2016, 5009.6–2016, 5009.4–2016. The total starch content was determined by kit assays .2.4.The total polyphenols, total flavonoids and individual flavonoid compounds were extracted and measured following the method of Qin et al.  with slio C and the injection volume was 20 μL.After the samples were passed through a 0.45 μm PEC syringe filter membrane , the individual flavonoid compounds including rutin and quercetin were analyzed by an Alltech HPLC system . The analytical column was a PerkinElmer® column  and the wavelength of the UV detector was set at 375 nm. The mobile phase was 0.05% trifluoroacetic acid aqueous solution (A) and 100% acetonitrile (B). A gradient flow system was established as follows with a flow rate of 1 mL/min: 0–5 min, 15–20% B; 5–25 min, 20–25% B; 25–35 min, 25–100% B; 35–40 min,100% B; 40–43 min, 100–15% B; and 43–48 min, 15% B. The column temperature was kept at 30 2.5.The color parameters of different instant powder samples were determined according to a procedure described by our laboratory  with sliWhere L* means lightness (0 for black and 100 for white), a* is red (+) to green (−), and b* is yellow (+) to blue (−).2.6.The DG of different instant powder samples were determined following a previous method . The sam1 and A2 represent the absorbance of the test sample and the control, respectively.Where A2.7.o C for 30 min with stirring every 10 min. The slurry was then centrifuged at 3100 g for 15 min, and the supernatant was transferred to an aluminum container. Subsequently, the supernatant and sediment were, respectively, dried to constant weight at 105 ° C. The WAI, WSI and SP were calculated according to the following Eqs 3–5:The water absorption index (WAI), water solubility index (WSI), and swelling power (SP) of instant powder were determined according to a previous procedure  with sma0 = the weight of the instant powder × (1–moisture content (%)). W1 is the weight of the sediment, and W2 is the weight of the solid dissolved in the supernatant.Where W2.8.o C for 2 h and then filtered. The supernatants were evaporated to dryness by vacuum rotary evaporator, then resolved with 70% ethanol solution and used for subsequent analysis.The instant powder samples (0.5 g) were accurately weighed and mixed with 30 mL of 70% (v/v) methanol solution. Each suspension was incubated in a water bath at 65 o C for 10 min, 120 μL 2.5 mM pNPG in phosphate buffer solution was added. Then the mixture was incubated at 37oC for 15 min and the reaction was terminated by adding 480 μL 0.2 M sodium carbonate. Finally, the absorbance was measured at λ = 405 nm. Acarbose was used as the positive control. The α-glucosidase inhibitory activity was calculated using the following formula:The α-glucosidase inhibitory activity of flavonoid extracts was assessed by using previous method  with sli0 and A1 represent the absorbance of the control and the experimental samples, respectively. The α-glucosidase inhibitory ability of the extracts was characterized by inhibiting 50% of the enzymatic activity (IC50).Where A2.9.Sensory evaluation of instant powder was conducted according to Chen et al.  with sli2.10.o C for 30 min, 5.0 mL of 0.02 M acetate buffer and 8 mL of enzyme solution  were added. The reaction solution was incubated at 37.0 o C with moderate stirring at 50 rpm. Aliquots were taken at 0, 5, 10, 15, 20, 30, 45, 60, 90, 120, 150, and 180 min to determine the glucose released by the D-glucose (GOPOD format) assay, which was then transformed into the amount of digested starch molecules.The digestion of instant powder was performed according to a previous method . Brieflyin vitro digestion; Resistant starch (RS): total starch minus amount of glucose released within 120 min of in vitro digestion. The contents of RDS, SDS and RS were calculated according to the following Eqs 7–9:According to previous study reported by Englyst et al. , three d0, G20, G120 are the glucose released (mg) within 0, 20, and 120 min, respectively. TS is weight of total starch (mg) in the sample. 0.9 (162/180) is the factor to convert from free D-glucose to anhydro-D-glucose as occurs in starch.Where GThe hydrolysis index (HI) was calculated as the area under the starch hydrolysis curves (AUC) of a sample as a percentage of the corresponding AUC of glucose . The est2.11.The starch digestion curves were fitted to an integrated first-order Eq. 11:t and C0 are the starch digestion ratios at time t and 0 (min), respectively; C∞ is the starch hydrolysis rate at the end of the digestion; and k is the starch digestion rate coefficient.Where CDifferent digestion phases were identified by using the logarithm-of-slope (LOS) analysis method described by Zou et al.  through ∞–C0), from which C∞ can be obtained. The slope in this study could be estimated from the fraction (C2–C1)/ (t2–t1), (C3–C2)/ (t3–t2) etc. And the natural logarithms plotted against the relevant, mean time, i.e., (t2 + t1)/2, (t2 + t3)/2 etc. A spread sheet can be set up to perform these relatively simple calculations. For substrates containing starch fractions digested at a single rate, the LOS plot is linear, while others may have multiple distinct linear phases. Therefore, the whole starch digestion can be expressed by a piecewise function. In the current study, we found that the plot is nonlinear, with two different linear regions with different slopes. C0 is determined experimentally, while the rest three parameters fast digestion rate coefficient (kf), slow digestion rate coefficient (ks) and C∞ are determined by the non-linear least-squares refinement in Excel to the global minimum. A complete fitting process was reported by Li et al.  against time has a slope k and intercept ln  were performed. Statistical analysis was performed using SPSS version 26.0 . The data were subjected to one-way analysis of variance (ANOVA) to determine the differences between samples. Significant differences were compared by Duncan test on the level of 3.3.1.p < 0.05). Previous studies have proved that extrusion treatment can significantly decrease the content of starch, protein and fat . The majority of flavonoids in instant powder were rutin, accounting for 71.84% (IE80) and 89.32% (ME80), and the proportion of quercetin was 1.41% (IE80) and 1.94% (ME80). Besides, as shown in Phaseolus vulgaris L.) lost 80% of its myristin content and 50% of its quercetin concentration during extrusion. Wang et al. . In contrast, instant powder obtained with IE showed higher redness  and yellowness  than instant powder obtained with ME . Moreover, as shown in p > 0.05), which suggested that the instant powders could be accepted by consumers. Overall, these two extrusion methods have negligible effects on color attributes from the view of consumers.Color is one of the key quality parameters that directly affect consumer acceptance. Color characteristics reflect starch gelatinization, caramelization, and Maillard reaction induced by extrusion . Previou3.3.p < 0.05), indicating that the two extrusion modes have varying effects on ordered structure of starch crystallinity. On the other hand, it has been reported that extrusion caused the formation of amylose-lipid complex and its supramolecular structure and then retained the crystallinity structure, which decreased the degree of gelatinization . The possible reason was that the high protein content in the instant powder obtained with IE exhibited a strong ability to compete for water with other ingredients, which led to an increase in WAI (p < 0.05), indicating that there are differences between the two extrusion modes in terms of how much starch and polymer are degraded. Moreover, heat treatment resulted in the loss of solubility of other molecules or the creation of insoluble components, masking the increase in soluble starch (p > 0.05). Previous studies have shown that there were two main factors responsible for the change of SP. One was that the crystalline structure of starch was broken down during the extrusion process, and the liberated amylose and amylopectin can form hydrogen bonds with water molecules to increase SP  than instant powder obtained with ME , which was consistent with the trend of total flavonoids content , suggesting that both IE and ME have no significant impact on the sensory quality of these two instant powder samples.Sensory analysis of different instant powder samples is summarized in 3.7.in vitro starch hydrolysis curves of the instant powder samples were shown in in vitro starch digestibility of Tartary buckwheat depends on food composition and microstructure formed during food processing . This was consistent with the DG trend of instant powder samples shown in The ocessing . The sus3.8.f) and a significantly lower rate constant (ks) for all starchy samples, suggesting starch digestion proceeded successively with a fast and slow step. According to previous study (f (0.4024) in comparison with instant powder obtained with IE , whereas there was no significant difference in ks value . This indicated that the fast-digesting component of starch in instant powder was significantly impacted by these two extrusion modes. Generally, differences in the hydrolysis kinetics of starch are attributed to the interplay of many factors, such as starch source, granule size, the degree of molecular association among chemical components among others . This indicated that instant powder obtained with IE had greater resistance to the enzyme hydrolysis than instant powder obtained with ME probably due to the lower DG in IE80 . According to the values of DG and WAI, the instant powder obtained with IE was more compact, the substances were aggregated and combined and the contact between the enzymes and starch was less, leading to lower eGI value. This observation was in agreement with the RDS changes and further demonstrated that the gelatinization promoted the digestibility of starch . This indicated that phenolic compounds are an important factor affecting the color parameters, hydration characteristics, starch digestibility as well as α-glucosidase inhibitory activity. The α-glucosidase inhibitory activity and RS contents were significantly and positively correlated with the levels of total polyphenols, total flavonoids, rutin and quercetin as well as WAI, and significantly and negatively correlated with the DG and WSI, whereas the C∞, kf, RDS, HI and eGI showed the opposite trend. In addition, A significant correlation was shown  between C∞ and RDS, SDS, and RS, and kf showed significant correlation with RDS, SDS and RS . Similar results were reported by Zhang et al. . Similar result was reported that RS content in whole buckwheat noodles was inversely related to eGI (r = −0.983)  . Based o4.in vitro starch digestibility. However, there was no significant difference in the sensory properties of instant powder. The instant powder obtained with IE could retain more protein and ash content as well as higher WAI, whereas the instant powder obtained with ME could retain more starch and fat content as well as higher DG. In particular, the instant powder obtained with IE showed particularly low levels of digestibility and fast digestion rate coefficient, as well as higher RS content and α-glucosidase inhibitory activity. These findings indicated that instant powder obtained with IE could serve as an ideal functional food resource with anti-diabetic potential.This work indicated that the two extrusion modes induce a significant effect on the phytochemical composition, DG, hydration and color properties of different instant powder samples and strongly influences its α-glucosidase inhibitory activity and The original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding authors.ZZ: investigation, data curation, and writing–original draft. YL: methodology and formal analysis. LZ: material and formal analysis. YX: software and formal analysis. ML: visualization. BX, ML, and YH: writing–review and editing. GR: methodology and writing–review and editing. LZ: supervision and resources. PQ: supervision, conceptualization, and funding acquisition. All authors contributed to the article and approved the submitted version.This work was supported by grants from National Key R&D Program of China (Grant No. 2020YFD1001400), Shanxi Provincial Key Research & Development Project (202102140601014), and Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences (Grant No. CAAS-ASTIP-2017-ICS).The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


The eccentric RHS (rectangular hollow sections) joint offers improved mechanical properties and better space utilization. Its use in frame structures has gained significant attention. Currently, the initial rotational stiffness of RHS joints, the simplified finite element analysis method of eccentric RHS joints, and the influence of the spatial effect of RHS joints are still unknown. The purpose of this research is to establish a calculation formula for the initial rotational stiffness of eccentric RHS joints, study the influence of the spatial effect under complex stress conditions, and propose a mathematical model that can be used to simplify the analysis of eccentric RHS joints. The research findings indicate that the web plate’s deformation stiffness primarily influences the joints’ initial rotational stiffness. This increases with a higher beam-to-column depth-to-width ratio, beam-to-column thickness ratio, and column width-to-thickness ratio. The form of the moment distribution in the joint changes, and begins to have a significant effect on the rotational stiffness when the beam-to-column flange width ratio reaches and exceeds 0.7. The stiffeners have a direct additive effect on the joint stiffness. The influence of adjacent beams on the joint is minimal, and the spatial effect of the joint can be disregarded. Furthermore, the finite element analysis confirmed the accuracy of the power function model in accurately simulating the static load behavior of the joint, particularly the bending moment–angle relationship. The application of steel tube structures can be traced back to the St. Louis Bridge in the United States in 1867 . Steel tIn steel tube structures, the main components are tubular hollow sections and rectangular hollow sections. Consequently, intersecting joints are classified into tubular joints and RHS joints. Tubular joints have a longer research history compared to other types of intersecting joints. Scholars have extensively studied tubular joints with T-shaped ,4, K-shaThe utilization of rectangular steel tubes as beam-column members and the adoption of eccentric intersecting joints in frame structures have gradually gained prominence in the construction of prefabricated buildings and outdoor elevator shafts. This approach allows for a smooth outer surface of the building, enhancing both the aesthetic appeal and space utilization. As part of this development, eccentric RHS joints have been introduced, wherein the axes of the beam-column members are perpendicular to each other, and the outer webs are flush. Notably, there are existing applications of eccentric RHS joints, such as the Shanghai World Expo Spain Pavilion . DespiteGuo et al. conducted tests on eccentric RHS joints, and focused on summarizing the in-plane flexural capacity of eccentric RHS beam-column joints . The finMu: Ultimate bending moment,t1: Length of plate corresponding to stiffening,l: Thickness of the plate corresponding to the stiffening,h: Indicates the moment arm provided by the upper and lower stiffeners,fy: The yield strength of the steel,β*: Width ratio correction, which is related to the joint geometry.Currently, the research on eccentric RHS joints still has the following problems: firstly, the research on eccentric RHS joints was limited to the bearing capacity. The research on the initial rotational stiffness of RHS joints is still lacking. Secondly, the finite element analysis of eccentric RHS joints was limited to solid elements. The simplified finite element analysis method of eccentric RHS joints is still lacking. Additionally, the research on eccentric RHS joints was limited to a single beam direction. In practical frame structure applications, a TT-shaped joint space with two adjacent beams at 90° is often formed, where both beams in different directions may experience significant loads. Therefore, the influence of the spatial effect under complex stress conditions is still unknown.η), width ratio correction (β*), column diameter to thickness ratio (γ), beam to column wall thickness ratio (τ). The selection principles for these geometric parameters can be referenced from literature [Based on the results of existing research , this stterature ,22. SecoThe joint form studied in this paper is a T-shaped eccentric RHS joint. The joints are divided into two types: non-stiffener joints and stiffener joints. The beam and the outer edge of the column are aligned in a non-stiffener joint. A stiffener joint is based on the non-stiffener joint, and a stiffening thickness of 6 mm is welded on the upper and lower flanges of the beam and the column. The length of the stiffeners along the beam direction is 120 mm. The column member is a rectangular hollow section that is □ 200 × 8 mm, and the beam member is a rectangular hollow section of □ 250 × 150 × 6 mm. The joint constructions are shown in The finite element software ABAQUS 2018 was used to simulate the eccentric RHS joints. Considering the calculation accuracy and costs comprehensively, all of the components, stiffeners, and welds in this research were divided into structured grids using a three-dimensional linear reduced integration element (C3D8R). The mesh of the finite element model not only needs to ensure the analysis accuracy of the calculation model, but also needs to consider the calculation efficiency. Therefore, the mesh of the finite element model established in this study was finer at the locations with complex stress distribution, large stress gradients, and complex contact relationships, and the mesh was relatively rough for the rest of the parts. The element size at the end of each member was 20 mm. The element sizes of 5 mm, 10 mm, and 20 mm were used for mesh refinement transitions from the intersecting surface to the rod end, respectively. It was divided into 4 layers in the thickness direction . Accordify) was 450 MPa, the ultimate stress (fu) was 650 MPa, the elastic modulus (E) was 2.08 × 105 MPa, the tangential modulus (E′) was 0.005E, and Poisson’s ratio (ν) was 0.3.In the analysis of the eccentric RHS joints, a reference point (RP point) was established at the centroid of the end section. Constraints and loads were applied to the RP point under the following conditions: the bottom of the column was fully constrained in all degrees of freedom, while the top only released the in-plane rotational degrees of freedom and vertical translational degrees of freedom. A continuous vertical force was applied at the top of the column. The connection surface between the weld and the member was bounded by the binding constraint. A bilinear strengthening model was employed for the material constitutive model, considering the true stress and strain. The material properties obtained by the material property experiment were as follows: the yield stress (β (b/B), beam height to column flange width ratio η (h/B), column tube wall width-thickness ratio γ (B/2T), and beam-column section wall-thickness ratio τ (t/T). The objective was to examine the influence of these geometric parameters on the static performance of eccentric RHS beam-column joints.In this study, 60 models of eccentric RHS beam-column joints and 50 models of eccentric RHS beam–column joints with stiffening ribs were created to investigate the static performance of these joints. The models were developed by varying the geometric parameters such as the beam-column flange width ratio B) was equal to the column height (H). The numerical models of the eccentric RHS beam-column joints were named following a specific format: for example, for “J-P-p1-p2”, “J” represents the joint type, “P” denotes the main geometric parameters studied in the group of models, “p1” denotes the column section width B in the group of models, and “p2” denotes specific values of the main variation parameters of the specimens. “+” represents the joint with stiffeners. Detailed information about the modeling, including the specifications of all numerical models of the eccentric RHS beam–column joints, can be found in Since the column members mostly had square cross-sections with equal heights and widths, this study focused on the case where the column width  to (4).The calculation formula for the initial stiffness terature , as showThe finite element calculation results are shown in β) of 1. Taking leff = 2.5T and bringing it into Equation (4), because the wall thickness (T) is approximately equal to the wall thickness of the beam (t), and the column height (H) is much greater than (t), according to the forms of Formula (2)~Formula (5), the initial rotational stiffness K0 of the eccentric RHS joint can be written in the form of Formula (6). The coefficient (k) can be obtained through parameter analysis.At the initial stage of bending, the mechanical behavior of eccentric RHS joints closely resembles that of equal-width T-joints with a flange width ratio (η(h/B), the bending moment was still borne by the eccentric side. However, the height of the beam increased, the stress area of the joint increased, and the development of plastic deformation became more complete. The initial rotational stiffness K0 of the joint increased linearly with an increase in η(h/B). The influence of η(h/B) can be fitted by a linear function. In β*(2b/B − 1), the width of the beam increased, and the bending moment was distributed more to the non-eccentric side. The initial rotational stiffness K0 of the joint increased non-linearly with an increase in β*(2b/B − 1). In γ(B/2T) is beneficial for enhancing the initial rotational stiffness K0. To some extent, increasing the beam-column wall thickness ratio τ(t/T) can also improve the initial rotational stiffness K0. The initial rotational stiffness K0 of the joint increased non−linearly with the γ(B/2T) and τ(t/T). The influence of β*(2b/B − 1), γ(B/2T), and τ(t/T) can be fitted by a quadratic function. The final coefficient (k) can be written in the form of Formula (7), where C1~C8 are undetermined constants. Using the data of 60 finite element models for parameter fitting, the fitting results are shown in Formula (8); most of the errors are less than 10%, and the maximum error is about 17%, which can obtain the initial rotational stiffness of the joint more accurately.The results of finite element parameter analysis are shown in Figure. 4. In According to the component method, the presence of a stiffener in the joint can be considered as an equivalent spring connected in parallel at the joint. This additional spring enhances the rotational stiffness of the joint. By analyzing the stiffness contributed by the stiffener, we can determine the overall stiffness of the joint with the stiffener. This stiffness is then combined with the stiffness of the joints without a stiffener to obtain the total rotational stiffness of the joint. Detailed information about the modeling, including the specifications of all numerical models of eccentric RHS beam-column joints, can be found in K0) resulting from the presence of a stiffener in the eccentric RHS joints. By analyzing the parameters that influence the increase in bearing capacity, the main factors affecting ΔK0 can be determined. The geometric parameters, namely the stiffener thickness (tl), beam height (h), and length (l), were investigated, as shown in K0 is directly proportional to tl and l, indicating that larger dimensions of the gusset plate lead to a more pronounced enhancement in joint stiffness through the stiffener. Furthermore, ΔK0 exhibits a linear relationship with the beam height (h), with a positive intersection point on the x-axis. This signifies that the stiffener’s ability to improve the joint stiffness may be limited when the beam height is small. This can be attributed to the reduced longitudinal deformation along the beam direction, which hinders the effective contribution of the stiffeners.Formula (9) represents the incremental value of the initial rotational stiffness . Conversely, changes in other geometric parameters of the beam-column members and modifications to the stiffener shape exhibited a relatively smaller effect on ΔK0. Notably, the parameter η was primarily achieved by altering the beam height (h), which was not explicitly considered in the final formula to avoid redundancy.The parametric analysis results of the geometric parameters influencing the joint dimensions are presented in K0) of the joint is expressed by Formula (10), and a parameter fitting was performed using the data from 50 finite element models established in this research. The fitting result is presented in Formula (10). When calculating the effect of the stiffener on the rotational stiffness, the contribution of the stiffener was ignored if the calculated ΔK0 was negative. The effect of the stiffener on the joint rotational stiffness was calculated using Formula (11), while the initial rotational stiffness of the joint without a stiffener was calculated using Formula (8). These two values were then added together to obtain the initial rotational stiffness of the joint with a stiffener. The maximum error (Δmax) was −11.21%, and the average error (Δavg) was −0.24%, demonstrating that the results met the engineering accuracy requirements.Finally, the increment of the initial rotational stiffness . When the shape coefficient of the power function model is set to 3, it provides a good simulation of the joint’s loading process. When applying this model to the strengthened ribbed joint of the eccentric RHS joint, the moment-rotation curve of the joint closely matches the calculated results obtained from finite element analysis ) can effectively simulate the entire loading process of the joint. analysis .(12)θr=Directly using solid elements for modeling requires significant computational time when conducting structural calculations. It is common in the design process to employ a beam system model for the overall analysis and design of the structure. The effect of different joint connection types on the final calculation results in frame structures cannot be simply ignored. Therefore, it is necessary to address how to incorporate the effect of joint semi-rigidity into the beam system model.The mathematical model of the eccentric RHS joint’s static performance under in-plane bending was established in this study. A rotational spring element was introduced at the intersection of the beam and column components to account for the effect of joint semi-rigidity in the beam system model. This method uses beam system units instead of solid units for finite element modeling, which greatly reduces the computational complexity and improves the computational efficiency.The beam system model established in this study is shown in P is the vertical load at the loading point at the beam end, and Δ is the vertical displacement at the loading point at the beam end. It can be seen from The calculation results of the finite element model of the beam system are shown in In the case of the solid models, when the load on the joint reached the ultimate carrying capacity, the load still increased slightly with displacement. However, when the load on the joint reached the ultimate carrying capacity, the load could not be significantly increased in the case of the beam system models. This limitation arose from using the power function model, where the maximum load-bearing capacity that the joint could achieve was the ultimate carrying capacity. The model did not account for any strengthening effect that may have occurred after the joint reached its ultimate carrying capacity.To validate the mathematical model’s accuracy for the joint’s static performance at the structural level, a finite element model of a frame structure was established. The 1/4th structure was considered to simplify the calculations, as shown in The finite element analysis results of the frame structure are shown in The beam model yielded the following results for the maximum displacements: 75 mm for the first layer, and 129 mm for the second layer. On the other hand, the solid model produced the following results: 73 mm for the first layer, and 126 mm for the second layer. The calculated results from both modeling approaches are essentially identical, with a small discrepancy in the displacement calculations of only 2.67% and 2.34% for the beam and solid models, respectively. This demonstrates the effectiveness of the proposed simplified calculation method for the eccentric RHS joint when applied to frame structure analysis.(1)K0) of eccentric RHS joints is primarily influenced by the tension-compression deformation stiffness (kcw) of the web. It increases with the height-to-column flange width ratio (η) and the beam-to-column wall thickness ratio (τ). Meanwhile, the column’s wall width-to-thickness ratio (γ) increases with these ratios’ increments.The rotational stiffness ((2)K0) does not change significantly when the beam-column flange width ratio (β) is less than 0.5. It increases significantly with an increase in (β) when (β) is greater than 0.5, indicating that the bending moment distribution form of the joint changes.The rotational stiffness ((3)Considering the force mechanism of the eccentric RHS joint, the side plate connected to the stressed beam and the web plate on the eccentric side bear most of the load, while the plates on the other two sides of the rectangular tubular column member are minimally affected. Therefore, for a T-shaped space joint with a 90° included angle, the mutual influence between the two stressed beams can be disregarded.(4)To simulate the semi-rigid effect of the joint, this study adopted a nonlinear corner spring model. Compared with the solid element analysis, the ultimate bending moment error of the joint is only 1.0%, the average lateral displacement error in the frame structure is only 2.5%. The finite element analysis confirmed the accuracy of the power function model in accurately simulating the static load behavior of the joint, particularly the bending moment-angle relationship.This research comprehensively investigated the in-plane bearing capacity of eccentric RHS beam-column joints. We analyzed the formula for the initial rotational stiffness of the joint, and explored the influence of spatial effects on its performance. The following conclusions can be drawn:


Neointima formation and hyperplasia in vascular grafts may lead to graft complications threatening the patency of the vascular reconstruction. A rare complication to endovascular treatment of grafts and stent grafts is dissection inside the graft.We present here a case of a 69-year-old female with acute occlusion of the limb of an aorto-bifemoral graft for the third time, 16 years after the primary operation. As at the first two occasions, catheter-based intra-arterial thrombolysis was performed, but with residual stenosis inside the graft. During stent placement, dissection of the neointima or fibrin sheet occluded the inflow to the stent. The complication was resolved with placement of kissing stents.It is important to recognize iatrogenic neointima dissection inside graft and stent grafts, as continued thrombolysis will not solve this, but increase the risk of hemorrhagic complications. Neointima formation and hyperplasia in vascular grafts may lead to graft complications threatening the patency of the vascular reconstruction . EndovasA 69-year-old female patient with a long vascular history and atrial flutter, presented with acute critical limb ischemia of the left extremity after stopping her anticoagulation (apixaban).She had received an aortobifemoral graft at the age of 53, and had two prior episodes with acute occlusion of the right limb of the graft, 10 and 14 years after the primary operation. Both occlusions was resolved with catheter-directed thrombolysis, the last time with application of a stent in the proximal part of the right limb of the graft.CTA confirmed occlusion of the left leg of the aortic-bifemoral bypass, and new short occlusions of two calf arteries. There was also wall thrombus in the native aorta above the graft, as well as in the main body of the graft.After discussion with the vascular surgeon, we started catheter-based intraluminal tPA-administration via a crossover hook-shaped catheter, with the intention to aspirate residual emboli from the calf the next day if needed.After 12 h, the thrombus was dissolved. There was significant residual stenosis due to neointimal hyperplasia or wall adherent thrombus in the proximal limb, and the left groin was punctured to apply kissing stents at the bifurcation of the graft Fig. . The disEmboli to the left calf were aspirated via a new antegrade puncture in the left groin, but completion angiograms showed some residual thrombi and a chronic occlusion of the dorsal pedal artery.The patient is back to her habitual state 6 months after the procedure, with no rest pain or wounds, but claudication at 500 m. Initially after the procedure the patient received dual antiplatelet therapy, but she was reinstated on apixaban from the cardiologist due to atrial flutter at dismissal from the hospital. She is currently on life-long anticoagulation and antiplatelet therapy with apixaban and ASA.While neointimal hyperplasia is a common occurrence, especially at the anastomotic site of vascular grafts, neointimal dissection is more rare. Iatrogenic dissections of the neointima has been reported from invasive cardiology procedures , as wellIn our experience, the dissection can be mistaken for residual thrombus, and while continued thrombolysis will not solve this problem, the systemic effect of tPA can increase the risk of intracranial hemorrhage. As for intimal tears and subintimal dissections, it is important how the dissection flap influence hemodynamics. If there is no hemodynamic significant stenosis, and the tear does not pose risk to further progression to cause occlusion or thrombus formation, the dissection can be left untreated. If the flap needs treatment, prolonged balloon inflation can be attempted or a stent can be placed inside the graft.In our experience, the neointima of stent grafts and grafts does not dissect easily, but when the dissection occur, it tends to extend rather long, often all the way to the anastomosis or the end of the stent graft. This is in contrary to iatrogenic subintimal dissections during vascular interventions, as they are often more limited, possibly due to atherosclerotic plaques and diseased vessel walls.


For many types of cancer, chemotherapy is still widely used, but it can cause serious side effects because it kills all rapidly growing cells, not just the cancerous ones. In this paper, a nanoparticle-based drug delivery system has been designed to selectively deliver a highly cytotoxic drug to tumor cells. The nanoparticles, obtained from a protein called silk fibroin, have been loaded with a naphthalene diimide derivative, namely NDI-1, which kills cells by affecting their DNA. The surface of the silk fibroin nanoparticles has been decorated with cyclopentapeptides incorporating the Arg-Gly-Asp sequence (cRGDs) to specifically target the tumor cells, thus reducing the harm to healthy cells and minimizing side effects.cRGDs) to provide active targeting toward glioma cell lines that abundantly express ανβ3 and ανβ5 integrin receptors. Cytotoxicity and selective targeting were assessed by in vitro tests on human glioma cell lines U373 (highly-expressing integrin subunits) and D384 cell lines (low-expressing integrin subunits in comparison to U373). SFNs were of nanometric size (d50 less than 100 nm), round shaped with a smooth surface, and with a negative surface charge; overall, these characteristics made them very likely to be taken up by cells. The active NDI-1 was loaded into SFNs with high encapsulation efficiency and was not released before the internalization and degradation by cells. Functionalization with cRGDs provided selectivity in cell uptake and thus cytotoxicity, with a significantly higher cytotoxic effect of NDI-1 delivered by cRGD-SFNs on U373 cells than on D384 cells. This manuscript provides an in vitro proof-of-concept of cRGD-silk fibroin nanoparticles’ active site-specific targeting of tumors, paving the way for further in vivo efficacy tests.Developing drug delivery systems to target cytotoxic drugs directly into tumor cells is still a compelling need with regard to reducing side effects and improving the efficacy of cancer chemotherapy. In this work, silk fibroin nanoparticles (SFNs) have been designed to load a previously described cytotoxic compound (NDI-1) that disrupts the cell cycle by specifically interacting with non-canonical secondary structures of DNA. SFNs were then functionalized on their surface with cyclic pentapeptides incorporating the Arg-Gly-Asp sequence ( Finding novel and effective cancer treatments is a key issue on a global scale . DespiteAlthough some NDIs have also reached clinical trials in humans , they caThe integrin superfamily members such as α4β1, α5β1, α6β4, ανβ3, and ανβ5  are ideaPeptidic and peptidomimetic compounds incorporating the Arg-Gly-Asp (RGD) sequence are known integrin antagonists with potential applications in anticancer therapy ,30. If lBombyx mori cocoons, is one of the most promising, as it possesses all the ideal characteristics mentioned above. The literature is rich in examples where silk-fibroin nanoparticles (SFNs) have been used to deliver different biologically active compounds, including cytotoxic ones, and they have also been functionalized to provide active targeting [cRGDs) [Although this assumption works very well theoretically, putting it into practice is a whole different thing. To develop a drug delivery system characterized by all these properties, choosing a biocompatible and biodegradable material with good mechanical properties and endowed with functional groups that allow easy functionalization is mandatory. Among the most employed materials for the preparation of NPs, silk fibroin, a protein extracted from argeting ,37,38,39 [cRGDs)  capable  [cRGDs) .cRGDs towards tumor cell lines that highly express αvβ3 and αvβ5 integrin receptors.Given these premises, this work aimed, for the first time, to exploit SFNs to encapsulate and deliver NDI-1, a highly cytotoxic tetrasubstituted naphthalene diimide derivative. The selective active targeting was provided by functionalizing the surface of SFNs with RGD-based cyclopentapeptides. Both loaded and unloaded, naked, or functionalized SFNs were fully characterized by size and size distribution, zeta potential, physical-chemical properties, morphology, and ultrastructure. Finally, formulations were tested to demonstrate the selective cytotoxic effect of NDI-1 loaded into SFNs functionalized with ® HSS C18 column . The following method was used: isocratic gradient over 2 min 95% of H2O + 0.1% trifluoroacetic acid (5% acetonitrile), gradually to 40% aqueous solvent over 6 min, then isocratic flow for 4 min . Purification of the final product was carried out by using an Agilent Technologies 1260 Infinity preparative HPLC  provided with a diode array UV-vis detector, using a Waters XSelect® CSH Prep C18 OBDTM column  at 30 mL/min flow rate. Aqueous solvent: 0.1% trifluoroacetic acid in water; organic solvent: acetonitrile; gradient: 95% aqueous for 2 min after injection, gradually to 40% aqueous over 16 min . UPLC-MS data were recorded employing a UPLC system  supplied with a BEH Acquity UPLC column (1.7 μm) 2.1 × 50 mm, and an LCQ ADV MAX ion-trap mass spectrometer, with an ESI ion source. In addition, 1H- and 13C-NMR spectra were recorded on a Bruker Avance 300 MHz .Solvents and reactants for the synthesis of the active compound NDI-1 were purchased from Carlo Erba, Zentek, and Merck , and were used as supplied without further purification. Yields were calculated for compounds purified by HPLC chromatography and judged homogeneous by thin-layer chromatography, NMR, and mass spectrometry. Microwave irradiation was performed with a Discover microwave synthesizer . Reactions were monitored by analytic HPLC using an Agilent system SERIES 1260  with XSelectBombyx mori cocoons were kindly donated by Nembri Industrie Tessili S.r.l., Capriolo, Italy. All the reagents for preparing and characterizing SFNs were purchased from Merck  and used without further purification. All the dialyses were performed using cellulose tubes purchased from Spectrum Laboratories .Human glioma cell lines (U373 and D384) were purchased from the European Collection of Authenticated Cell Cultures Cell Bank . All reagents used for cell cultures were purchased from Euroclone .The synthesis and characterization of NDI-1 were already reported in the literature ; neverthBombyx mori cocoons were cut into 1 × 1 cm sections and boiled in 100 °C water with 0.02 M Na2CO3 for 30 min to solubilize the sericin. The fibroin fibers were then washed with deionized water, left to dry at room temperature, and then solubilized in LiBr 9.3 M at 60 °C for 4 h. The fibroin solution was filtered through a 70 μm nylon mesh, placed into dialysis cellulose tubes , dialyzed against distilled water for 72 h at room temperature, and diluted to reach a 1.5% w/v concentration. NDI-1 was solubilized in the fibroin solution at the final concentration of 0.31 mg/mL, and the mixture was then desolvated in acetone (fibroin:acetone ratio 1:5). Unloaded SFNs were prepared following the same procedures but without adding NDI-1. SFNs and SFNs-NDI-1 were placed into dialysis cellulose tubes  and dialyzed against distilled water for 72 h at room temperature. The nanoparticles were then freeze-dried at −46 °C with 0.28 mbar pressure .Silk fibroin nanoparticles were prepared according to the procedure previously reported by our group . BrieflycRGD derivative carrying an azide moiety (N3-cRGD) was performed by following the protocol reported in our previous works [The synthesis of the us works ,43,44.cRGD  in DMSO (150 μL), a 0.01 M aqueous solution of CuSO4 , and a 0.01 M solution of sodium l-ascorbate  were then added to the reaction flask. After 72 h, the cRGD-functionalized nanoparticles were submitted to dialysis against distilled water at room temperature for 48 h.The surface of both unloaded (SFNs) and loaded (SFNs-NDI-1) nanoparticles was modified using the same functionalization strategy. SFNs or SFNs-NDI-1  were suspended in a phosphate buffer  for 1 h to ensure their complete hydration, then a 10 mg/mL DMF solution of the alkyne linker was added . After 24 h, the alkyne-functionalized nanoparticles were purified through dialysis against water at room temperature for 48 h. The alkyne-functionalized nanoparticles  were then suspended in a phosphate buffer  for 1 h to ensure their complete hydration. A solution of N3-The yield % was calculated according to Equation (1):cRGD-SFNs-NDI-1, the nanoparticles were solubilized in LiBr 9.3 M at 60 °C for 4 h (2 mg/mL). The UV-visible spectra of the solutions were registered with an Agilent Cary 60 spectrophotometer , recording the absorbance from 200 to 900 nm wavelength interval at a scan rate of 50 nm/min and a slit width of 0.5 nm. Emission spectra were run on a Cary Eclipse Fluorescent Spectrophotometer  and recorded from 636 nm to 850 nm by exciting at 616 nm. A scan rate of 600 nm/min, averaging time 0.1 s, data interval 1 nm, excitation and emission slits 5 and 10 nm, were used to obtain the spectra as an average of 3 scans. A quartz cuvette of 10 mm path length was used. The characteristic absorbance and emission spectra of NDI-1 were used to correctly quantify its load in the silk fibroin nanoparticles. To calibration lines, NDI-1  was suspended in a 100% w/v LiBr solution (1 mL) and heated at 60 °C for 4 h. Absorbance calibration lines were obtained by plotting the maxima of NDI-1 characteristic bands (365 nm and 616 nm) versus NDI-1 concentration from 0.25 μM to 2.5 μM. Using the same NDI-1 concentrations, the emission calibration lines were obtained by plotting the maximum emission bands at 657 nm, recorded with the slits opened at 10 and 5 nm. All measurements were conducted in triplicate by obtaining four calibration lines with R-square coefficients of determination equal to 0.998 ± 0.001, 0.997 ± 0.005, 0.999 ± 0.009, 0.99 ± 0.01, respectively. Finally, the drug loading was calculated according to Equation (2):To quantify the NDI-1 loading into SFNs-NDI-1 or The mean diameter and the particle size distribution were measured for all the formulations by a NanoSight NS300 . The nanoparticles were dispersed in water at 0.05 mg/mL and sonicated before the analysis. Five measurements of 90 s each were repeated for each sample, and the data were elaborated by the NTA software 3.0 provided by the manufacturer.The zeta potential was measured using the Zetasizer nano ZS90 after the dispersion of SFNs at 1 mg/mL in KCl 1 mM. Each analysis was performed in triplicate.The infrared spectra of all nanoparticles were acquired with an Alpha II FT-IR spectrometer with a platinum Attenuated Total internal Reflectance (ATR) module , and data were elaborated with Opus 7.8 software.For SEM analysis, the freeze-dried samples were placed on the stub and gold-sputter-coated under argon. The images were acquired by MIRA3 . TEM images were acquired by a JEOL JEM 1200 EX instrument. The samples were dispersed in water at the final concentration of 0.1 mg/mL; a drop of the sample suspension was then placed onto a 300-mesh nickel grid coated with carbon and let dry for 24 h at room temperature (25 °C) before analysis. Cryo-EM images were acquired by a Cryo transmission electron microscope Glacios . The sample suspension (0.1 mg/mL) was placed on a grid (Quantifoil R 1.2/1.3 Cu 300), and the images were acquired.v/v fetal bovine serum, 1 mM glutamax, 1% v/v antibiotics (penicillin-streptomycin), and 1 mM pyruvate  at 37 °C under a humidified atmosphere containing 5% CO2.U373 and D384 human glioblastoma cell lines were selected for the assays and purchased from the ECACC collection . The cells were cultured at 37 °C in DMEM supplemented with 10% To assess integrin subunits expression in U373 and D384 cells, the mRNA expression of αv, α5, β1, β3, and β5 were evaluated as previously described . In briesample is the absorbance of the tested samples and Abscontrol is the absorbance of cells not treated with any samples.Cell viability assays were performed using the MTS assay after 24 and 72 h treatments. The cells were seeded in a 96-well plate (5000 cells/well) and cultured with their culture media, as described in p < 0.05.The software STATGRAPHICS XVII  was used to elaborate raw data. As all data presented a normal distribution, a linear generalized analysis of variance model (ANOVA) was used, and the differences between the groups were evaluated with Fisher’s least significant difference (LSD) procedure. Statistical significance was set at 50 = 25 μM [50 values of 104.7 nM and 28.7 nM, respectively (by sulforhodamine B assay), the therapeutic window was very narrow, with a negligible selectivity over normal human fibroblast line WI38 (IC50 = 292 nM) [Tetrasubstituted and tetracationic NDIs are well-known for being excellent G-quadruplex ligands, with a considerable selectivity towards these secondary structures concerning single- and double-stranded nucleic acid sequences . However = 25 μM . Neverth 292 nM) . Its syn 292 nM) .90 was always lower than 150 nm.Silk fibroin nanoparticles were then prepared by inducing the coacervation of fibroin with acetone; therefore, starting from a homogeneous solution of fibroin and, in the case, NDI-1, at the end of the coacervation process, the active was entrapped in the fibroin matrix. The process yield was above 75% for all the batches prepared, and all the formulations were found to be nanometric in size, as reported in w/w, with an encapsulation efficiency above 95%. Attempts were made to change the initial fibroin:NDI-1 ratio to gain SFNs with higher theoretical loading, but the actual drug loading was never above 1% w/w. It was supposed that NDI-1, a rigid, planar, and aromatic structure, can bind and settle only in the amorphous portions of fibroin chains that are more flexible, thus accommodating and firmly binding a flattened molecule such as NDI-1. It is likely that, after desolvation, fibroin is mainly present in the β-sheet form, which has a very compact texture, and thus there is not much space for NDI-1 in the matrix when the theoretical composition is above 1% w/w. Indeed, according to the literature [−1 (due to C=O stretching), precisely 1622.15 cm−1, the absorption peaks of amide II at around 1520 cm−1 (due to N-H bending), specifically at 1515.18 cm−1, and the peak of the amide II band at around 1266 cm−1 , specifically at 1260.89 cm−1  was performed by exploiting an azide-alkyne “click reaction” between the azide group of the RGD-based cyclic pentapeptide and triple bond-functionalized SFNs  of the reaction mixture afforded pure cRGD-SFNs or cRGD-SFNs-NDI-1.The preparation of zed SFNs . The funcRGDs did not change the main characteristics of the nanoparticles. Following functionalization, the loading of the active compound was preserved (1.2 ± 0.3% w/w), as well as the nanometric size  and explains why flocculation was observed during the dialysis process .Next, the cytotoxic effect of nanoparticles was investigated in vitro, specifically on the human glioma U373 and D384 cell lines. Firstly, the integrin expression pattern in the selected cell lines was evaluated by real-time qRT-PCR analysis. The data in Subsequently, the active compound NDI-1 was tested on U373 cells at different concentrations  and time of contact (24 and 48 h) to identify the minimum effective concentration and time. A concentration of 1 μM induced a marked decrease in cell viability after 24 h of contact .cRGD functionalization made the nanosystem selective, all SFNs formulations were tested. The tests were performed on the U373 cell line, overexpressing αv, β3, and β5 integrin subunits, and the D384 cell line, expressing these integrin subunits in amounts markedly lower than U373, as assessed by real-time RT-PCR analysis. At first, a dose-dependent effect for SFNs loaded with NDI-1 was observed: for both cell lines, the cytotoxic effect increased after increasing the tested concentration . The effectiveness of the functionalization in providing selectivity is further supported by the zeta potential data (cRGD-SFNs-NDI-1 and the cell membrane (both negatively charged), the internalization by the U373 cell and the resulting toxic effects are marked. This is probably due to the overexpression of integrin receptors, which counteracted and overcame the unfavorable effects of electrostatic repulsion.After 72 h of treatment, unloaded SFNs, either functionalized with ll lines . Conversial data : despitew/w of NDI-1 with a high encapsulation efficiency (over 95%); (iii) the loaded active is retained by the protein matrix of fibroin, and it is released and exerts its cytotoxic effect only after internalization and degradation of SFNs in the cytosol; (iv) the functionalization with cRGDs made the uptake of SFNs by cells that overexpress αvβ3 and αvβ5 integrin receptors selective.Overall, the formulated nanoparticles had the following characteristics: (i) morphology, size, and surface charge that make them optimal for cell uptake; (ii) ability to load up to 1% cRGDs), making the uptake by cells that overexpress αvβ3 and αvβ5 integrin receptors selective. The encapsulation of NDI-1 into cRGD-SFNs could prevent it from exerting systemic cytotoxic effects. Moreover, following accumulation in the tumor (guided by the EPR passive targeting and active uptake by tumor cells), the high cytotoxicity of NDI-1 could be selectively directed towards malignant cells overexpressing αvβ3 and αvβ5 integrin receptors. Therefore, this manuscript provides the in vitro proof-of-concept of cRGD-SFNs active site-specific targeting for tumor site-specific delivery, paving the way for in vivo studies and in vitro innovative models as alternatives to animal use.In this work, compound NDI-1, a tetrasubstituted naphthalene diimide derivative with potent cytotoxic anticancer activity, was encapsulated into SFNs with a high encapsulation efficiency. Active targeting was provided for SFNs by functionalizing their surface with cyclic pentapeptides bearing the RGD sequence (


Experience with durable biventricular assist devices (BiVADs) as a bridge to heart transplantation (HTx) is limited, particularly in women. A 41-year-old woman with biventricular failure complicated by cardiogenic shock underwent durable concurrent BiVAD implantation and was supported for 1212 days as a bridge to HTx. During BiVAD support, she experienced bacteremia (day 1030 of support), appropriately managed with intravenous antibiotics. She is alive and well, 1479 days from BiVAD implantation and 267 days from orthotopic HTx. Strategies contributing to successful prolonged support include concurrent BiVAD implantation, aggressive cardiac rehabilitation, diet management for weight loss and frequent interval surveillance. Patients with biventricular failure requiring biventricular assist device (BiVAD) support have inferior post-implant outcomes compared to left ventricular assist device (LVAD) patients, with 1-year post-implant survival of ˂60%  mmHg), PCWP (10 mmHg) and CI  limits the ability to implant two intrathoracic VAD devices. In fact, over 88% of BiVADs in the last decade have been implanted in men . HoweverRight atrial cannulation versus right ventricular cannulation (in BiVAD support) is associated with improved outcomes . A systeIn this report, we highlight that long-term survival on BiVAD is possible with concurrent implantation, right atrial cannulation, aggressive cardiac rehabilitation, diet management for weight loss and frequent interval surveillance. While this patient was supported with HeartWare VAD devices, our current strategy includes biventricular HeartMate III implantation. She was supported for 1212 days and experienced methicillin-susceptible staph bacteremia after 1030 days of support. She experienced no other VAD complications and remains alive through latest follow-up, 1479 days after BiVAD initiation and 267 days after HTx.


The pre-gelatinization and co-gelatinization methods were also compared. SEM results showed that the presence of Ca(OH)2 promoted the connection and further strengthened the pore wall of the three-dimensional network structure of the gelatinized and retrograded TBS-rutin complex, indicating the complex possessed a more stable structure with the presence of Ca(OH)2, which were also confirmed by the results of textural analysis and TGA. Additionally, Ca(OH)2 reduced relative crystallinity (RC), degree of order (DO) and enthalpy, inhibiting their increase during storage, thereby retarding the regeneration of the TBS-rutin complex. A higher storage modulus (G′) value was observed in the complexes when Ca(OH)2 was added. Results of in vitro digestion revealed that Ca(OH)2 retarded the hydrolysis of the complex, resulting in an increase in values in slow-digestible starch and resistant starch (RS). Compared with pre-gelatinization, the complex process prepared with the co-gelatinization method presented lower RC, DO, enthalpy, and higher RS. The present work indicates the potential beneficial effect of Ca(OH)2 during the preparation of starch-polyphenol complex and would be helpful to reveal the mechanism of Ca(OH)2 on improving the quality of rutin riched Tartary buckwheat products.This study examined the effect of calcium hydroxide (Ca(OH) Fagopyrum, which is broadly cultivated and occupies a crucial part in Europe and Asia [Tartary buckwheat is a kind of crop of the family Polygonaceae and genus and Asia ,2. Compaand Asia ,3, whichand Asia . In addiand Asia . In receThe interaction between polyphenols and starch has been widely reported. The study found that quercetin had an effect on the morphological structure and thermal characteristics of pre-gelatinized starch; the addition of quercetin greatly reduced digestibility . He et a2. During the manufacturing process, adding Ca(OH)2 will raise the calcium content of noodles and promote the formation of the calcium-modified starch complex, which could be useful for enhancing the physicochemical properties of products [2 is also added to improve food quality characteristics. Palacios [2, while these changes have not been explained from the perspective of the interaction between starch and calcium [Tartary buckwheat is mostly consumed as noodles, steam buns, pancakes, and muffins in the main cultivation countries, such as China, Ukraine, Japan, etc. . Howeverproducts . In manyPalacios  discoverPalacios . Our pre calcium .2-starch and rutin is still unclear. Therefore, to evaluate how Ca(OH)2 and rutin affect the physicochemical characteristics of starch during processing, Ca(OH)2 and rutin interacted with TBS under different heating modes (pre-gelatinization and co-gelatinization). This research is expected to provide a new method for preparing starch-polyphenol complexes and be helpful in revealing the possible role and mechanism of Ca(OH)2 during the processing of Tartary buckwheat.Different processing methods may lead to differences in the composition and content of phenolic compounds in Tartary buckwheat products, but there is no comparative study between pre-gelatinization and co-gelatinization. Moreover, the mechanism of action between Ca(OH)Aspergillus niger was supplied by Aladdin Industrial Corporation .Tartary buckwheat flour was purchased from Saixue Grain & Oil Industry and Trade Co., Ltd. . Rutin was provided by Shanghai Yuanye Bio-Technology Co., Ltd. . Calcium hydroxide (food grade) was purchased from Guangzhou JIAYE food ingredients Co., Ltd. . Porcine pancreatin was purchased from Solarbio Science &Technology Co., Ltd. . Amyloglucosidase from According to a prior study , the TBS2 solution , the mixtures were stirred at room temperature for 10 min before being heated at 90 °C for 10 min with constant stirring at 150 rpm. Subsequently, 10 mL of rutin solution  was added into the pre-gelatinized starch solution, and we continued heating for 20 min with stirring at 150 rpm. Paste liquids were placed at room temperature for 1 h to obtain pre-gelatinized samples, marked for pre-TBSR and pre-TBSRCa; in order to get the retrograded sample, the pastes were kept at 4 °C (1 day) and labeled as pre-TBSR-1d and pre-TBSRCa-1d. After freeze-drying, all samples were ground and passed through 100 mesh sieves for further assessment.Pre-gelatinized complexes were prepared through previous literature  with som2 and rutin complexes were prepared according to the previous literature [2 solution ; the mixtures were stirred for 10 min at room temperature before being heated at 90 °C for 30 min with constant stirring at 150 rpm. Paste liquids were placed at room temperature for 1 h to obtain the co-gelatinization samples, marked for GTBS, GTBSCa, TBSR, and TBSRCa, in order to get the retrograded sample, the pastes were kept at 4 °C (1 day) and labeled as GTBS-1d, GTBSCa-1d, TBSR-1d, and TBSRCa-1d. After freeze-drying, all samples were ground and passed through 100 mesh sieves for further assessment.Co-gelatinized complexes of TBS, Ca(OH)1) was put into pre-weighed centrifuge tubes, added 5 mL distilled water and stirred continuously for 30 min at 90 °C. After cooling to room temperature, centrifuged at 4000 rpm for 20 min. Separate the sediment (W2) and supernatant, transfer the supernatant to a pre-weighed glass beaker and dried at 105 °C to constant weight (W3). The following formulas were used to determine the solubility and SP:The solubility and SP of samples were evaluated using a previous method . Fifty mMorphological characteristics of starch and complexes were analyzed through SEM  at 15.0 kV. The sample was stabilized on the surface of copper stubs before being thinly coated with gold, then observed under 20 kV.The starch (or complex) pastes were prepared according to the instructions in The TGA of all samples was measured using a Thermoanalyzer System  following the procedure proposed by Gao et al. . BrieflyAn X-ray diffractometer  was used to determine the crystal structures of all samples. The diffractometer worked at 40 kV and 100 mA with scanning radiation in the angular range of 4°–40° (2θ) at a scanning speed of 0.1°/s. Jade software version 6.0 was used to analyze the relative crystallinity of each powder.w/w) and equilibrated in an oven at 40 ° C; after grinding, we pressed the mixed power into sheets with a vacuum compressor. The FT-IR spectrometer  was used to determine the spectral data of all samples through 32 scans in a band with a texture number range of 400–4000 cm−1.The sample and KBr powder were mixed  of sample and added into 9 uL of distilled water, placed in aluminum pans before analysis. All samples were measured by differential scanning calorimeter  as presented by Yu . The DSC−1 and subsequently from 300 to 0.1 s−1 at a constant shear stress of 5 Pa to determine their apparent viscosity (Pas) and shear stress (Pa). A frequency sweep was performed on gel samples with constant deformation (2% strain) in a frequency range of 0.1 to 20 Hz at 25 °C.A rheometer  equipped with a parallel plate geometry and a probe  was used to conduct steady shear and frequency sweep investigations on all samples. All sample suspensions (1.5 mL) were deposited onto the metal platform in accordance with the previously reported procedure . All theThe in vitro digestibility of all samples was tested using the procedure presented by Englyst et al.  with sliG20 and G120 stand for the contents of hydrolysis glucose within 20 and 120 min; FG is free glucose content; T refers to the content of total starch; 0.9 is the conversion factor.p < 0.05 represents statistically significant differences.All statistical analyses were conducted using SPSS software , and variance (ANOVA) was used to measure statistical differences. 2 and rutin greatly improved the solubility of each sample, while it was not significant between pre-gelatinization and co-gelatinization methods. TBSRCa has a higher solubility than GTBSCa and TBSR, either in pre-gelatinized or co-gelatinized samples. Compared to GTBS, the SP of TBSR decreased significantly, and the reduction of SP of pre-TBSR is not significant, while the SP of GTBSCa, TBSRCa, and pre-TBSRCa increased. It can also be seen that the SP of TBSRCa was higher than TBSR but lower than GTBSCa.2 created pores on the starch surface and led more water and alkali into the starch, thus accelerating the protons’ separation from their hydroxyl groups on starch [2+ or Ca(OH)+ forms a complex with starch to destroy starch granules, leading to higher solution dispersion and solubility.Starch-water interactions could explain the increased solubility. On the one hand, interactions between the hydroxyl groups of phenolic acids in water change the water activity and ionic strength of an aqueous solution. This alteration encourages the dissolution of soluble starch , and then starch ; it migh2; the formation of alkaline conditions in the presence of appropriate amounts of Ca(OH)2 promotes the release of amylose from starch granules and the release of hydroxyl groups from starch chains, which may result in Ca2+ and Ca(OH)+ proton substitution. Interactions between Ca2+, Ca (OH)+, and starch increases the swelling capacity of particles [The decrease in SP might be attributed to the addition of rutin, which prevents the interaction between starch granules and amylopectin or amylose, limiting starch particle expansion force . Zhang earticles .Textural property is an important indicator of the gel system, among which gel hardness is commonly used to assess the amount of starch retrogradation during storage. 2 might be due to the role of Ca2+ ions, which may interact with starch chains that contribute to forming an interconnection network [2 as a cross-linker that enhanced the interaction between rutin and starch. At the same time, the firm gel structure can also be seen in SEM.Compared with GTBS, the decrease in hardness of pre-TBSR and TBSR samples may be due to the fact that the hydroxyl group on the polyphenol molecular chain can combine with the amylose molecule, which inhibits the formation of amylose double helix and regeneration crystallization , thus le network . The gel2 and rutin, are shown in 2 exhibited irregular solid particle aggregates. NTBS lost their native shape after hydrothermal treatment, and no residual starch granules can be observed in the gelatinized and retrograded samples, indicating that the present hydrothermal condition induced complete gelatinization of NTBS. All gelatinized (1–F1) exhibited a three-dimensional honeycomb network structure with a multidimensional void wrapped in the gel wall. However, it could be observed that the homogeneity and continuity of the gel wall were visible differences in the different samples. In contrast to GTBS 2  possessed a thicker gel wall than those samples without Ca(OH)2.The morphology characteristics of all samples, including Ca(OH)atinized A–F and ratinized A1–F1 exh to GTBS A, the co to GTBS C,F could to GTBS E,F. Howe to GTBS B has a m to GTBS A. The pr Ca(OH)2 B1,D1,F1 2 in TBS enhanced the formation of the hydrogel microarchitecture of GTBS, which was consistent with the findings of Cornejo–Villegas [2 to gelatinized starch formed a filamentous network and promoted the formation of the hydrogel microstructure. The presence of Ca(OH)2 in complexes of TBS and rutin smoothed and firmed the gel walls might be because that alkaline condition promotes the dissolution of rutin and makes it easily permeate into the starch matrix and interact with starch, generating a smoother and more compact starch reticular structure. During the preparation of the pre-gelatinized complex, rutin might be easier to deposit on the gel wall, rather than prevent the interaction of starch molecules, resulting in the pre-gelatinized complex of TBS and rutin showed the thicker and continue gel wall than co-gelatinized complex.The morphology of NTBS and rutin observed during this investigation is in accordance with earlier literature ,10. AleiVillegas , who ind2 facilitated the dispersion, smoothed the surface, and firmed the gel walls.In short, the present finding from SEM indicated rutin was dispersed in a starchy matrix and hindered the formation of continuous gel walls. Ca(OH)2 showed only one stage of decomposition around 400 °C, which is different from that of complexes. The thermal decomposition processes of complex prepared with pre-gelatinized and co-gelatinized exhibited two main steps. The first decomposition processes occurred immediately after warming up and ended before 200 °C. The second mass loss happened between 250–400 °C with the mass of GTBS decreasing from 90% to around 20%, and from 90% to around 26% for TBSR and pre-TBSR, while the mass of TBSRCa, pre-TBSRCa, and GTBSCa was reduced from 90% to around 23%. The remaining rate of the rutin and Ca(OH)2 was above 40% and 80% when the temperature reached 600 °C, while decreased to around 20% after adding into starch, indicating the formation of starch-rutin, starch-Ca(OH)2 and starch-rutin-Ca(OH)2 complex. DTG curves in max) of GTBSCa, TBSR, and TBSRCa was 320 °C, 321 °C, and 325 °C, respectively, either in pre-gelatinized or co-gelatinized samples, indicating an increase in their thermal stability in the presence of Ca(OH)2 and rutin. Retrograded samples presented similar trends to the gelatinized samples.According to max indicated an increase in the sample’s thermal stability in the presence of Ca(OH)2 and rutin, which were also reported in a previous study [max of the TBSRCa is slightly higher than that of the TBSR and GTBSCa, indicating that the TBSRCa loses less weight and has better thermal stability at the same temperature [The first stage of mass loss represents the removal of water and low molecular compounds present in the samples. Starch molecules contain some water, and the hydrophilicity might be due to the hydrogen bond formed by the hydroxyl group of the glucose unit . The secus study , which fperature .An amorphous pattern with broad peaks was observed either in pre-gelatinized or co-gelatinized samples. The rutin crystalline peak can be seen at 26.43° in pre-TBSR and TBSR, but its intensity decreased in pre-TBSRCa and TBSRCa. 2 and rutin had no effect on the crystalline shape of the pasted starch, which is consistent with previous reports on buckwheat starch [2 and rutin affects the starch retrogradation to various degrees, whether pre-gelatinization or co-gelatinization. At the same storage time, both TBSRCa and TBSRCa -1d had the lowest RC values, and the RC of gelatinized complexes grew slowly compared to gelatinized starch, implying that the presence of Ca(OH)2 and rutin may inhibit the formation of recrystallization of starch, delays the retrogradation of GTBS.As evaluated by X-ray diffractometry, the original crystalline shape of the gelatinized and regenerated starch was lost, but the presence of Ca(OH)t starch . After pt starch . Roskhrut starch  also sugt starch , similar−1 band of all samples were determined, as shown in −1  [Infrared spectroscopy is sensitive to chemical bond oscillation frequency, and vibrational modes are related to starch conformation and crystallographic order . The FT-der, DO)  was disp−1 indicates stretching of the -OH group in starch or phenolics, which could be observed in all complexed and GTBS. The OH− stretching in Ca(OH)2 is represented by the absorption peak at 3642 cm−1, which only was found in the Ca(OH)2, and could not be observed in the complex added with Ca(OH)2. The absorption peak at 1650 cm−1 is associated with C-O-O stretching vibration of carbohydrates, and the absorption peak at 2930 cm−1 is associated with the C-H stretching vibration [−1 were related to the vibrational modes of the amorphous regions of starch, whereas the bands at 1022 and 1047 cm−1 were correlated with the number of ordered regions [2 and rutin interfere with the formation of ordered structures in the starch crystal region. Chai et al. [According to i et al.  also obs2+ ions does not form new chemical bonds in the starch matrix, but the Van der Waals interactions might affect the physicochemical characteristics of starch [It was noticed that there were no new characteristic peaks in TBSR or pre-TBSR, which demonstrated that the rutin would not lead to the formation of new chemical bonds in starch samples . Furtherf starch ,33.P) values of GTBSCa were significantly higher by about 4°C, while the gelatinization enthalpy (ΔH) value decreased from 9.44 to 7.09. Compared to GTBS, the onset temperature (TO), TP, conclusion temperature (TC), and ΔH values of TBSR and pre-TBSR were decreased, the TO, TP, and TC values of TBSRCa and pre-TBSRCa were higher than GTBS, TBSR, and pre-TBSR and were lower than GTBSCa, and the ΔH value of TBSRCa was the lowest among the starch complexes. We found that the change in trends of retrogradation enthalpy (ΔHr) was consistent with the ΔH, the ΔHr value of all complexes was significantly lower than that of GTBS-1d, and the ΔHr value of TBSRCa-1d was the lowest. Meanwhile, the value of the co-gelatinized sample was lower than that of the pre-gelatinized sample.The parameters of DSC with all samples were observed in O, TP, and TC values of the starch sample decreased with the addition of rutin, and ΔH was reduced to different degrees, implying that the starch gel was less susceptible to retrogradation under the presence of rutin. Previous research found that alkali treatment can increase the gelatinization temperature of starch and reduce ΔH value [O indicates that the melting of starch granules starts at a higher temperature [2 dissociates into Ca2+ and OH− ions in the process; the higher the amount of OH− anions, the easier it is to penetrate the starch granule and destroy the hydrogen bond in the starch chains, which enhances the gelatinization process [2 and rutin reduced the enthalpy of gelation of TBS, implying that they reduced the energy required to change from suspension to gelation state. Moreover, TBSRCa had the lowest ΔH, which may be caused by the connection among starch, rutin and Ca(OH)2. The lower ΔH of complexes indicated that the presence of Ca(OH)2 and rutin inhibited TBS retrogradation. The starch complexes showed obviously lower ΔHr, which was similar to the trend of starch enthalpy reported by Tang et al. [2 is beneficial to delay the buckwheat starch’s retrogradation, as well as co-gelatinization has a better effect.Wang et al.  found thΔH value , which iperature . Ca(OH)2 process . ΔH repr process . The addg et al. , that th2, the apparent viscosities of TBSRCa, pre-TBSRCa, and GTBSCa were higher than that of GTBS, while GTBSCa has the highest apparent viscosity, which could be attributed to the formation of a strong and continuous network, resulting in an improvement in the consistency of the starch complexes [The rheological properties of all the samples are depicted in omplexes .2 complex has a low tan δ value, indicating that Ca(OH)2 will affect the rheological behavior of the starch-rutin complex, and Ca(OH)2 may be beneficial to the release of amylopectin, thus affecting its viscoelasticity [2 are used as molecular chaperones to assist in the reorganization of starch, which may form a starch network or a starch-rutin-Ca(OH)2 architecture.asticity . The assInteractions between starch and other food ingredients have been shown to influence in vivo starch digestion and postprandial blood glucose response. In vitro digestibility changes of all samples were diagrammed in 2 and rutin, indicating that the in vitro digestibility of GTBS could be greatly impacted by rutin and Ca(OH)2. Similar digested results were displayed in retrograded samples. The change of digestibility is as follows: the starch sample without any substance has the highest digestion rate, the digestion rate of samples treated with rutin or Ca(OH)2 was significantly lower than GTBS, and TBSRCa was the lowest. Moreover, the digested rate of complexes with the pre-gelatinization method is slightly higher than that of the co-gelatinization method.From 2 and rutin promoted the conversion of RDS and SDS to RS in TBS. The same changes were applied to the retrograded samples. Wang et al. [2 complexes is most likely the primary cause of the reduction in starch digestibility.The contents of the RDS, SDS and RS complexes are presented in g et al.  studied g et al. . Gao et g et al.  also foug et al.  found th2 on structural, physicochemical, and in vitro digestibility properties of complex of TBS and rutin were investigated in this study, and pre -gelatinization and co-gelatinization methods were compared. The present study has shown that Ca(OH)2 promoted the connection of the three-dimensional network structure of gelatinized and retrograded TBS-rutin complex and effectively inhibited the retrogradation of TBS. TBSRCa possessed lower RC, DO and enthalpy values, lower digestibility, and higher content of RS compared to other samples. The rheological results also showed that TBSRCa modified the viscoelastic behavior of starch pastes. Compared with pre-gelatinization, complexes prepared with the co-gelatinization method presented better properties.The effect of Ca(OH)2 and rutin is conducive to the gelatinization of TBS, and Ca(OH)2 treatment should be taken into consideration as a potentially effective method for preparing starch-polyphenols complexes. In the future, more research using modern analytical means is needed to clarify the formation mechanism of starch-polyphenol complexes in the presence of calcium hydroxide at the molecular structure level and bond valence level.In short, the addition of Ca (OH)


In this work, the effect of iron(III) in the preparation of a conductive porous composite using a biomass waste-based starch template was evaluated. Biopolymers are obtained from natural sources, for instance, starch from potato waste, and its conversion into value-added products is highly significant in a circular economy. The biomass starch-based conductive cryogel was polymerized via chemical oxidation of 3,4-ethylenedioxythiophene (EDOT) using iron(III) p-toluenesulfonate as a strategy to functionalize porous biopolymers. Thermal, spectrophotometric, physical, and chemical properties of the starch template, starch/iron(III), and the conductive polymer composites were evaluated. The impedance data of the conductive polymer deposited onto the starch template confirmed that at a longer soaking time, the electrical performance of the composite was improved, slightly modifying its microstructure. The functionalization of porous cryogels and aerogels using polysaccharides as raw materials is of great interest for applications in electronic, environmental, and biological fields. Natural polymers enable the production of innovative materials within the framework of the principles of the circular economy, and it is a key strategy to balance progress and sustainability . The cirFrom the technological perspective, the capacity to modulate biomaterial properties to convey unique characteristics allows their application in different fields. Biopolymers are excellent raw material candidates for aerogel processing regarding circular economy principles, relying on renewable raw materials or energy sources ,11,12. AConductive porous materials possess a unique combination of properties and have become a global hot topic in the fields of catalysis, drug delivery, electronic devices, extracellular matrices, and tissue regeneration ,23,24,25In this work, the effect of iron(III) in the preparation of a conductive porous composite using a biomass waste-based starch template was evaluated. The starch-based conducting porous material was obtained through the chemical oxidation of 3,4-ethylenedioxythiophene (EDOT) using iron(III) p-toluenesulfonate. Our study is a step forward to previous works ,19,21 siSodium hydroxide , hydrochloric acid , 3,4-ethylenedioxythiophene , iron(III) p-toluenesulfonate hexahydrate , potassium bromide , and 2-Propanol  were purchased from Sigma-Aldrich .Potato tubers from agricultural waste were obtained from a local market in Cartago, Costa Rica, and were used as biomass source in accordance with CONAGEBIO permission R-CM-ITCR-002-2023-OT. The biomass was proceeded based on the following references ,41.Briefly, starch isolation was carried from the tubers using ca. 300 g of discarded potatoes, then thoroughly washed using deionized water and detergent, peeled, and sliced into small pieces. The tuber pieces were ground using a home blender , and the homogenate obtained product was suspended in 1 L of deionized water containing NaOH (0.1% wt.). The suspension was filtered, and sample was allowed to settle down for 4 h.The obtained sediment was washed four times using NaOH (0.1% wt.), and it was neutralized using HCl, and the supernatant was removed. The obtained residue was centrifuged for 5 min at 5000 rpm and stored at −20 °C for 24 h. Then, the sample was lyophilized for 72 h at −60 °C  and stored in conical tubes before their use. The starch extraction yield percentage was calculated through a mass analysis of the fresh tuber and the amount of starch obtained after lyophilization.Once the starch was isolated, starch-based cryogels were prepared. First, an aqueous solution containing starch 9% wt. was autoclaved  for 7 min at 121 °C and 1 atm. Then, samples were maintained for 48 h at 4 °C for starch retrogradation . The resOnce the cryogels were obtained, PEDOT was synthesized via oxidative chemical polymerization of EDOT onto the starch scaffold, adapted from previous work . The sta𝑠𝑘𝑒𝑙) was determined using a nitrogen pycnometer  set at room temperature and 15 psi. A total of 10 replicates were used for each measurement. The bulk density (𝜌𝑏𝑢𝑙𝑘) of the cylindrical cryogels was calculated by weighing and measuring the dimensions of each cryogel before functionalization and after soak times in iron(III) and EDOT polymerization. Equations (1) and (2) were used to calculate cryogels’ overall percentage porosity (ε) and total pore volume (𝑉𝑝), respectively, according to a previous report [Skeletal density of polysaccharide-based cryogels (𝜌s report .(1)ε =1BET) of the polymerized cryogels at different soak times in iron(III) solution was determined by applying nitrogen physisorption using the BET (Brunauer-Emmett-Teller) method in an adsorption analyzer . The characterization of the specific pore volume (Vp) and the mean of pore diameter (Dp) were estimated using the BJH  method. Finally, micrographs of the polymerized cryogels were recorded via scanning electron microscopy .The specific surface area  spectrometer  controlled with the OMNIC v9.3.30 software. For the analysis, PEDOT-polymerized starch cryogels were ground using a mortar and mixed with potassium bromide (KBr). The obtained powder was pressed using a Specac Atlas™ manual 15T hydraulic press  to obtain a pellet. Measurements of the acquired pellets were made in transmittance mode in the 4000–400 cm−1) was maintained during the analysis with a scan rate of 10 °C·min−1 from 25 °C to 800 °C in alumina cups (110 μL) . Finally, the atmosphere was changed to synthetic air at a flow of 100.00 mL·min−1.Thermogravimetric analysis (TGA) was carried out for all cryogel samples after iron(III) immersion and polymerization in an SDT Q600 from TA Instruments . A nitrogen atmosphere  . The bulk material was packed on a sample holder and measured in the range of (2θ) 5°–55° with a cobalt (Co) anode and an Fe filter using a GaliPix detector with a 17.8 mm anti-scatter slit. The operating conditions including step size, voltage, and current were adjusted to 0.007°, 40 kV, and 40 mA, respectively. Finally, the 2θ data was recalculated from Cobalt-KThe total organic carbon (TOC) for the porous composites was measured using a CHNS analyzer  using ca. 50 mg of sample. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) analysis for the St/iron(III)/PEDOT cryogels after different soak times in iron(III) solution were analyzed using an energy dispersive X-ray spectrometer detector (EDS)  and tabletop SEM  with EDS Xplore Compact, Oxford, UK), applying a voltage of 30 kV. Image analysis was performed with the SMILE VIEW™ Lab software 2.1 .5 Hertz (Hz).The electrical properties of the conductive material were evaluated via electrical impedance spectroscopy on a potentiostat instrument . The analysis was carried out in a system of two electrodes made of copper strips; the conductive material was located between the 2 copper electrodes placed in a compression load of ca. 35 mg. The resistivity of each probe was obtained from the current vs. voltage curves corrected by the area and length. The impedance analysis was performed at 50 mV in a frequency range of 0.1 to 10The obtained starch from the discarded potato matter was in the range of 7.82 ± 0.10%, in agreement with those values reported in the literature . The extThe chemical composition of the composites at different soaking times was evaluated via infrared, thermogravimetry, and elemental composition. The obtained data confirmed starch-iron interaction and its effect on the conductive polymer deposition in the porous structure. Starch cryogels were poured into the IPA-iron(III) solution, and immediately, the coloration of the samples changed from white to dark yellow. This is attributed to the iron content in the solution, supposing that free ferric ions in the IPA-iron(III) solution bonded to the polysaccharide structure in accordance with previous reports .The modification of the starch cryogel sample caused by the iron ions was monitored via TGA analysis. As is shown in −1 show a shape change and shifting in the functionalized samples  soaking are shown in  samples b,c, indireaction ,46. Addi−1 is indicative of the stretching vibration absorption peak of C=O [−1 were attributed to coupled valent vibrations of the C–O and C–C bonds and deformational vibrations of the C–C–H and C–O–H bonds [The signal at 1640 cmk of C=O ,46. Shif−1 is identified for the starch template, and it was assigned to vibrations of the C–O–C group on the glycosidic bond; this signal shifted to 1125 cm−1 in polymerized samples, possibly related to the polysaccharide–iron interaction [The band at 1153 cmeraction .−1 are identified in the starch/iron template and the polymerized sample  with differences among St, St/iron(III), and St/iron(III)/PEDOT materials. These differences are attributable to the presence of iron(III) and PEDOT, as well as the reduction of empty spaces in the cryogels. The results agreed with previous reports using a similar concentration of corn starch [The textural properties of the resulting cryogels for each synthesis stage are shown in n starch  and for n starch . skel) values in the range of native starch (1.50 g·cm−3) [Differences were determined between skeletal density values. St and St/ iron(III) cryogels showed skeletal densities (𝜌 g·cm−3) . The pyc g·cm−3) ,52. PoroWe observed that the cryogel macroporous structure endured the polymerization process through all preparation stages without an evident collapse, as shown in TGA data demonstrated that no significant difference in ashes was observed after an 8 h soaking time, and a similar amount of conductive polymer was observed in the 24 h and 48 h of soak time samples see . Consequ3 as an oxidant in the absence of a template [XRD diffraction  analysistemplate . TherefoElemental analysis data  showed tElectrical impedance spectroscopy characterization (EIS) of the porous composites was performed using a previous model , which iThe real impedance (Z′) and imaginary impedance (Z″)  confirmeThe impedance data fitting was performed using Autolab NOVA 2.1.6. based on a previous model . The modOverall, biomass-waste starch was a suitable raw material to structure a porous template. The porous structure withstands the fabrication process with only slight differences in microporosity. The chemical composition at different soaking times was studied via infrared, thermogravimetry, and elemental composition, confirming that a longer soak time altered the starch–iron ions interaction. Additionally, the results evidenced the presence of PEDOT and counter ions through the synthesis process, and they influenced the electrical behavior of the obtained composites.Our work gives insights into the methodology to functionalize starch obtained from biomass waste using chemical polymerization of poly directly on the substrate. Thermal and spectrometric characterization of those composites allow us to detect and quantify the iron–starch interaction and the amount of oxidizing agent during the soaking time. Moreover, we have confirmed using electronic microscopy and nitrogen physisorption that the porous template endured the polymerization process through all preparation stages without an evident collapse on the macrostructure, slightly affecting the microstructure due to the PEDOT deposition on the template surface. Longer soaking times  unveiled, via impedance spectroscopy, a more complex electrical behavior, which is of great interest to a wide audience, including electronic, environmental, and biological applications. Finally, the conversion of potato waste into a conductive porous composite is an example of the potential preparation of innovative materials that balance progress and sustainability in a circular economy framework.