枯草芽孢杆菌对大豆蛋白-磷脂复合乳液在体外消化中稳定性的影响

Effects of Bacillus subtilis on the Stability of Soybean Protein-Phospholipid Composite Emulsion in Vitro Digestion

为探讨枯草芽孢杆菌在消化过程中对大豆蛋白-磷脂复合乳液稳定性的影响。本试验设计胃肠消化模型,通过对加菌与不加菌的O/W型和W/O型乳液的乳化活性指数(Emulsifying activity index,EAI)、乳化稳定指数(Emulsification stability index,ESI)、浊度、粒径、Zeta电位检测和显微观察,考察乳液是否出现分离、絮凝、聚集上浮等现象。结果表明,在胃消化阶段,O/W型和W/O型乳液EAI、ESI、粒径、电位都明显减小,显微观察显示液滴密度减小,体积增大;加入枯草芽孢杆菌的乳液与不加菌乳液相比,各指标减小的幅度更大。在小肠消化阶段,O/W型和W/O型乳液EAI和ESI整体呈上升趋势,而粒径和电位则明显下降,另外,两者的显微观察显示液滴密度减小,体积也减小。与不加菌的相比,加入枯草芽孢杆菌后乳液EAI、ESI、粒径显著降低,电位显著升高(P<0.05)。综合上述结果,枯草芽孢杆菌促进了大豆蛋白-磷脂复合乳液在消化过程中的破乳现象。

To investigate the effect of Bacillus subtilis on the stability of a soy protein-phospholipid complex emulsion during digestion.This experiment designed a gastrointestinal digestion model,calculated the emulsification activity index(EAI),emulsification stability index(ESI),turbidity,particle size,Zeta potential,and conducted microscopic observation for O/W and W/O emulsions with and without bacteria to investigate whether the emulsion was separated and flocculated,gathering and floating phenomenon.The results showed that in the digestive stage of the stomach,the EAI,ESI,particle size,and Zeta potential of the O/W and W/O emulsions all significantly reduced,and the micrograph showed that the droplet density reduced and the volume increased.Compared with the without bactericidal emulsion,the index of the emulsion decreased more significantly.In the digestive stage of the small intestine,the EAI and ESI of the O/W and W/O emulsions showed an overall upward trend,while the particle size and potential decreased significantly.In addition,the micrographs of both showed a decrease in droplet density and volume.After adding Bacillus subtilis,the EAI,ESI,particle size of the emulsion significantly reduced,and the potential significantly increased(P<0.05).Based on the above results,Bacillus subtilis promoted the demulsification of soybean protein-phospholipid complex emulsion during digestion.