发酵麦麸对面包膳食纤维组成及烘焙特性的影响

采用马克斯克鲁维酵母发酵麦麸制得富含天然酶的功能配料,分析麦麸发酵过程中纤维素酶活力变化,比较制作的麦麸面包(B₁)、发酵麦麸面包(B₂)、木聚糖酶麦麸面包(B₃)和复合麦麸面包(B₄)的膳食纤维组成及烘焙特性的差异。结果表明:马克斯克鲁维酵母具有较强的胞外β-葡萄糖苷酶生产能力,其酶活为6.98 U/g;在48 h麦麸发酵过程中,外切葡聚糖酶和β-葡萄糖苷酶的酶活不断提高,其酶活分别增加至6.06和21.70 U/g,不溶性膳食纤维(IDF)也持续降解至38.30 g/100 g。面团搅拌、醒发过程中,还原糖含量不断增加,且添加发酵麦麸的面包效果最明显。相比未发酵麦麸面包,添加发酵麦麸的面包体积、弹性及持水力都显著提升(p<0.05),气孔结构更加细腻。制作的4种面包中总膳食纤维(TDF)和阿拉伯木聚糖(AX)含量没有显著差异,而添加发酵麦麸及木聚糖酶都能促进面包中IDF和AX溶解。

Effect of Fermented Wheat Bran on Dietary Fiber Composition and Baking Characteristics of Bread

Kluyveromyces marxianus was used to ferment wheat bran as functional ingredient with natural enzymes, and celluase activity during fermentation was analyzed. The differences in dietary fiber composition and baking characteristics of wheat bran bread (B₁), fermented wheat bran bread (B₂), xylanase wheat bran bread (B₃), and composite wheat bran bread (B₄) were compared. The results indicated that K. marxianus exhibited abundant extra cellular β-glucosidase production ability with an enzyme activity of 6.98 U/g, exoglucanase and β-glucosidase activities increased to 6.06 and 21.70 U/g respectively, and insoluble dietary fiber (IDF) degraded gradually to 38.30 g/100 g during 48 h wheat bran fermentation. Reducing sugar content increased during dough mixing and fermentation, especially for fermented wheat bran enriched breads. Bread volumes, elasticity and water-holding ability of bread with fermented wheat bran were improved significantly (p<0.05), and its pores structures were more fine than unfermented wheat bran. No significant difference was showed in total dietary fiber (TDF) and araboxylan (AX) contents in four kinds of baked breads, and fermented wheat bran and xylanase could promote the dissolution of IDF and AX in bread.