The influence of xylanase and thermal treatment on the composition and interfacial rheology properties of whole wheat dough liquor

Effects of Co-Modification by Extrusion and Enzymatic Hydrolysis on Physicochemical Properties of Black Wheat Bran and Its Prebiotic Potential

Black wheat bran (BWB) is an important source of dietary fiber (DF) and phenolic compounds and has stronger nutritional advantages than ordinary WB. However, the low content of soluble dietary fiber (SDF) negatively influences its physicochemical properties and nutritive functions. To obtain a higher content of SDF in BWB, we evaluated the impact of co-modification by extrusion and enzymes (cellulase, xylanase, high-temperature α-amylase, and acid protease) on water extractable arabinoxylan (WEAX) in BWB. An optimized co-modification method was obtained through single-factor and orthogonal experiments. The prebiotic potential of co-modified BWB was also evaluated using pooled fecal microbiota from young, healthy volunteers. The commonly investigated inulin served as a positive control. After co-modification, WEAX content was dramatically increased from 0.31 g/100 g to 3.03 g/100 g (p < 0.05). The water holding capacity, oil holding capacity, and cholesterol adsorption capacity (pH = 2.0 and pH = 7.0) of BWB were increased by 100%, 71%, 131%, and 133%, respectively (p < 0.05). Scanning electron microscopy demonstrated a looser and more porous microstructure for co-modified BWB granules. Through in vitro anerobic fermentation, co-modified BWB achieved a higher content of Bifidobacterium and Lactobacillus than inulin fermentation. In addition, co-modified BWB induced the highest butyric acid production, indicating high potential as prebiotics. The results may contribute to improving technologies for developing high-fiber-content cereal products.

Enhancing the technofunctionality of γ-aminobutyric acid enriched germinated wheat by modification of arabinoxylan, gluten proteins and liquid lamella of dough

To enhance the technofunctionality of germinated wheat enriched with γ-aminobutyric acid, xylanase (Xyn) and glucose oxidase (Gox) were incorporated with emphasis on modifying the key components. Combination of Xyn and Gox enhanced steamed bread quality with optimum loaf volume and textural property. Continuous and dense gluten network was facilitated and improved viscoelasticity of dough. Water solubility of arabinoxylan (AX) enhanced with Xyn and the molecular weight was more homogeneous distributed throughout bread making process with Xyn and Gox. Polymerization behavior of α-/γ-gliadin and glutenin was suppressed in steamed bread, while incorporation of AX to insoluble proteins was enhanced by enzymes. In addition, the promoted formation of high molecular weight glycoprotein in the liquid lamella of dough enhanced the thermal stability of foams and contribute to superior quality of steamed bread. Results demonstrated that germinated wheat could be exploited as a functional ingredient with desirable technofunctionality by modification of the components.