双歧杆菌胞外多糖对酸豆乳品质的影响

为探索益生菌及其胞外多糖对酸豆乳的影响，利用产胞外多糖双歧杆菌及其活性多糖与传统发酵剂共同发酵豆浆，研究其对酸豆乳理化、感官及质构特性的作用。结果表明：添加双歧杆菌（107 CFU/mL）和其活性胞外多糖（质量分数0.3%，下同）均对酸豆乳凝乳速度及后酸化无显著影响（P＞0.05）。添加0.3%胞外多糖能显著提高酸豆乳的黏度、持水力和质构特性（P＜0.05）。添加产胞外多糖双歧杆菌107 CFU/mL，对发酵期间酸豆乳发酵速率及凝胶特性影响不大；在后酵期间产生86 mg/L 胞外多糖，显著提高酸豆乳的黏度和质构特性（P＜0.05），但对产品持水力的影响并不显著（P＞0.05）。双歧杆菌胞外多糖可有效改善酸豆乳凝胶特性，提高产品品质。

Effect of Exopolysaccharides Produced by Bifidobacterium on Properties of Soya Yogurt

In order to explore the effect of addition of probiotics and probiotic exopolysaccharides (EPS) on properties of
soya yogurt, the physicochemical, sensory and texture properties of soya yogurt fermented by a traditional starter culture
combined with Bifidobacterium animalis subsp. lactis after addition of EPS produced by the probiotic strain were examined.
Changes in pH, water-holding capacity, apparent viscosity, EPS content and texture properties were determined during
fermentation and storage over 21 days. The results indicated that water-holding capacity, apparent viscosity and texture
properties of soya yogurt containing 0.3% EPS were significantly higher than those of the blank control (P < 0.05). The
addition of the EPS-producing bacterium had no effect on fermentation speed and gel properties of soya yogurt, but the EPS
(86 mg/L) produced during post-fermentation storage at 4 ℃ for 24 h led to a significant improvement in apparent viscosity
and texture properties (P < 0.05), while not significantly influencing water-holding capacity (P > 0.05). This study led us
to conclude that addition of EPS produced by Bifidobacterium animalis subsp. lactis was effective for improvement of gel
properties and quality of soya yogurt.