植物乳杆菌在体外消化中对大豆蛋白-磷脂复合乳液的影响

Effect of Lactobacillus plantarum on soy protein-phospholipid complex emulsion in vitro digestion

以大豆分离蛋白和磷脂作为原材料,制成稳定的水包油(oil/water,O/W)型和油包水(water/oil,W/O)型大豆蛋白-磷脂复合乳液,研究植物乳杆菌对乳液的影响。通过分析乳液经唾液,胃液,肠液消化时粒径、电位、稳定性和微观结构的变化,发现在胃中,乳液油滴不断变大,电位、乳化活性指数(emulsifying activity index,EAI)和乳化稳定指数(emulsifying stability index,ESI)下降;O/W型不加菌乳液粒径从3405 nm降到1858 nm,加菌乳液粒径从3826 nm降到2204 nm,W/O型不加菌乳液粒径从5269 nm降到1963 nm,加菌乳液粒径从5680 nm降到2449 nm;在小肠中,乳液油滴均一,EAI和ESI增加,O/W型不加菌乳液粒径从1434 nm降到691 nm,加菌乳液粒径从1684 nm降到687 nm,不加菌乳液电位绝对值在7 h达到最大值(75.73),大于加菌乳液的最大值(70.66);W/O型不加菌乳液粒径从2317 nm降到1221 nm,加菌乳液粒径从2201 nm降到1314 nm,不加菌乳液电位绝对值在7 h达到最大值(75.66),大于加菌乳液的最大值(70.06)。O/W型乳液和W/O型乳液具有显著性差别(P<0.05),植物乳杆菌对大豆蛋白-磷脂复合乳液具有显著影响(P<0.001),说明O/W型乳液比W/O型易消化,植物乳杆菌加剧了乳液的破乳。

Soy protein isolates and phospholipids were used as emulsifiers to make stable oil/water(O/W)and water/oil(W/O)soy protein-phospholipid composite emulsion,and the effect of Lactobacillus plantarum on the emulsion was studied.The changes of particle size,potential,stability and microstructure of emulsion were analyzed during digestion through saliva,gastric juice and intestinal juice.Results showed that in the stomach,the emulsion oil droplets continuously increased,and the potential,emulsifying activity index(EAI)and emulsifying stability index(ESI)decreased.The particle size of O/W bacteria-free emulsion decreased from 3405 to 1858 nm,in the bacterial emulsion,it decreased from 3826 to 2204 nm.The particle size of W/O bacteria-free emulsion decreased from 5269 to 1963 nm,in W/O bacterial emulsion,it decreased from 5680 to 2449 nm.In the small intestine,the emulsion oil droplets were uniform,and the EAI and ESI increased.The particle size of O/W bacteria-free emulsion decreased from 1434 to 691 nm,while in the bacterial emulsion,it decreased from 1684 to 687 nm.The absolute value of the potential in bacteria-free emulsion reached the peak(75.73)at 7 h,which was greater than the maximum value of bacteria-free emulsion(70.66).The particle size of W/O bacteria-free emulsion decreased from 2317 to 1221 nm,while the particle size of bacterial emulsion decreased from 2201 to 1314 nm.The absolute value of the potential of bacteria-free emulsion reached a peak(75.66)at 7 h,which was larger than that of the bacteria-free emulsion(70.06).There was a significant difference between O/W and W/O emulsion(P<0.05).L.plantarum had a significant effect on soy protein-phospholipid composite emulsion(P<0.001),indicating that O/W emulsion is easier to digest than W/O,and L.plantarum exacerbates emulsion demulsification.