Effect of virgin coconut meal (VCM) on the rheological, micro-structure and baking properties of cake and batter
Virgin coconut meal (VCM) cakes were prepared by replacing refined wheat flour (maida) (5 to 20 % level) to check its effect on chemical, textural and rheological attributes of cake. The addition of VCM significantly (p ≤ 0.05) increased redness (a*), yellowness (b*) while reduced lightness (L*) of cakes. The incorporation of VCM affects the hardness, adhesiveness gumminess and chewiness of cake. The effect of flour replacement with VCM increased the viscosity of batter which leads to increase in consistency index and lower the shearthining behavior. The viscoelastic behavior of cake batter in which elastic modulus (G’) and viscous modulus (G”) both were decreased with the increase in percentage of VCM. The differential scanning calorimetry (DSC) analysis revealed that the onset (To), end set (Tc) and enthalpy of gelatinization (ΔH) increased with the increased level of VCM.
EVALUATION OF FERMENTED PALM KERNEL MEAL AND FERMENTED COPRA MEAL PROTEINS AS SUBSTITUTE FOR SOYBEAN MEAL PROTEIN IN LAYING HENS DIETS
Two hundred and ten (210) laying hens of Black Harco breed at 37 weeks in lay were fed experimental layer diets, in which fermented palm kernel meal (PKM) and copra meal (CM) were used independently to substitute for soybean meal (SBM) on protein content basis at 0%, 25%, 50% and 75%, to give seven treatments in a completely randomized design feeding trial that lasted 12 weeks. Performance characteristics and some haematological indices were evaluated in this study. Fermentation for seven days increased the crude protein of PKM (from 20.04% to 23.42%) and that of CM (from 19.63% to 23.11%). The crude fibre of the fermented PKM and CM decreased (from 15.47% to 12.44 % and 16.00% to 11.63% respectively). The feed intake (FI) was significantly highest (P 0.05) by the substitution of PKM and CM for SBM. The study showed that SBM protein could be substituted optimally at 50% by either PKM or CM protein.
Modelling of Mooney viscosity relaxation in natural rubber
Abstract Better assessment of natural rubber (NR) quality and processability, through the identification of new attributes, is still a major challenge. With this scope, 12 model samples of natural polyisoprene and two of synthetic polyisoprene were characterized in terms of Mooney torque relaxation, using the standardized ISO289 method (ML(1+4)100, explained later in the Section 1 ). The main purpose of this study was to identify a model that gave a better fit for the experimental decay of Mooney torque over time (ML(t)=f(t)) than the usual power law model used before (Y=at−b, [G.M. Bristow, A.G. Sears, The use of novel parameters in the assessment of natural rubber processability, NR Technol. 18 (1987); H.G. Burhin, W. Spreutels, J.M. Campbell, MV2000 Mooney viscometer: Mooney relaxation measurements on raw polymers and compounded rubber stocks, Kautsch. Gummi Kunstst. 43 (1990) 431]). The results showed that a generalized Maxwell model, and the Wu–Abbott empirical model ( Y = 1 − a Ln ( t ) − ( b t / ( c + t ) ) ) [T. Wu, J.A. Abbott, Firmness and force relaxation characteristics of tomatoes stored intact or as slices, Postharvest Biol. Technol. 24 (2002) 59–68], recently used for describing stress relaxation of tomato flesh, allowed a better description of the relaxation curve for the samples studied than the power law or stretched exponential traditionally used. Moreover, the total relaxation time (τm) given by the generalized Maxwell model showed good correlation with the total gel content of the samples studied.