Co-Culture Probiotic Fermentation of Protein-Enriched Cereal Medium (Boza)
Abstract Objective: Boza is a fermented cereal beverage which is produced by co-culture fermentation of lactic acid bacteria and yeasts. In addition to the nutritional properties of cereals used in the production, it is also suitable to be gaining functional properties by fermenting with probiotic microorganisms. Methods: In this study, protein content of probiotic boza was increased by the addition of gluten, zein and chickpea flour and the volatile compounds formed during co-culture fermentation of the cereal medium with Lactobacillus acidophilus, Bifidobacterium bifidum and Saccharomyces boulardii were determined. Results: It was determined that chickpea added boza provided the highest cell counts of Lactobacillus acidophilus (7.92 logs CFU/g), Bifidobacterium bifidum (7.32 log CFU/g) and Saccharomyces boulardii (3.26 log CFU/g) during storage. With the addition of gluten, the protein content of the sample was enriched four times more when compared with control boza. During fermentation and storage, a total of 36 different compounds were identified with the major compounds as 9,12-octadecadienoic acid, 9-octadecenoic acid, hexadecanoic acid and hexadecanoic acid, 2-hydroxy-1-(hydroxymethyl)ethyl ester. The concentration of volatile compounds generally decreased during storage of samples. According to Principle Cluster Analysis results, enriched protein samples had similar projections due to their fatty acid contents and the main difference was shown in the control sample. Conclusions: The results of this study indicate that chickpea, single or mixture with cereals, can be a good substrate for probiotic microorganism production for acceptance as probiotic foods.
Solid-state fermentation with probiotics and mixed yeast on properties of okara
Abstract The effect of solid-state fermentation with compound probiotics and two types of yeast (Saccharomyces cerevisiae and Hansenula sp.) on the composition and selected quality attributes of okara were studied. Four different fermentation schemes, i.e., compound probiotics fermentation (P), mixed yeast (Saccharomyces cerevisiae and Hansenula sp.) fermentation (SH), co-fermentation of compound probiotics and mixed yeast (P + SH) and two-stage fermentation of compound probiotics and mixed yeast (P-SH) were comparatively assessed for their proximate composition, abilities to improve selected physicochemical, antioxidant, functional properties and sensory attributes (flavor and taste) of okara. The results showed that all the fermentation schemes could significantly improve the proximate composition, physicochemical as well as antioxidant activities and sensory attributes of okara. The bitterness and astringency of the okara were also reduced. The P-SH samples contained crude fiber of 12.0 g/100 g dry sample, total phenols of 154 mg gallic acid equivalence/100 g dry sample, free amino acids of 3.80 g/100 g dry sample. The DPPH free radical scavenging capacity and ABTS free radical scavenging capacity of the P-SH samples were 776 mg Trolox equivalence/100 g dry sample and 487 mg Trolox equivalence/100 g dry sample, respectively. The P + SH sample produced more alcohol, ester and other important flavoring substances than the other three methods. However, the P + SH sample had a relatively acidic taste.
Interaction of Formaldehyde and Tetrahydrofolic Acid and Its Relation to the Enzymic Synthesis of Serine
Interaction of Formaldehyde and Tetrahydrofolic Acid and Its Relation to the Enzymic Synthesis of Serine