摘要
该研究旨在阐明酪蛋白/乳清蛋白比例及食物基质对益生菌胃肠道存活特性的影响及作用机制。以菌粉固体饮料为对照组,酪蛋白和乳清蛋白质量配比分别为4∶1、2∶1、1∶1、1∶1.5的益生菌发酵乳为实验组,分别测定了它们在动态体外仿生儿童胃肠道消化模型内连续消化2 h期间胃/肠pH值、表观聚集态结构及总乳酸菌(包含保加利亚乳杆菌、嗜热链球菌和嗜酸乳杆菌)、乳双歧杆菌存活率的变化。结果表明,在相同的消化环境下,菌粉饮料的胃pH最低而肠pH最高,发酵乳胃消化期间形成的凝聚物进入肠消化后逐渐消失;无论是总乳酸菌还是乳双歧杆菌在所有发酵乳样品中的胃肠存活率显著高于在菌粉饮料中的存活率(P<0.05);随着酪蛋白/乳清蛋白比例的增加,发酵乳中总乳酸菌在胃和小肠内存活率均显著提高(P<0.05),但乳双歧杆菌的存活率差异较小。酪蛋白胶束较强的pH缓冲能力以及胃酸环境下形成的凝聚物,对益生菌具有一定的保护作用,进而提高其胃肠道存活率。
To elucidate the effects and mechanisms of casein/whey protein ratio and food matrixes on the gastrointestinal survival of probiotics in fermented milk,the probiotic fermented milk samples with different casein:whey protein mass ratio(4∶1,2∶1,1∶1 and 1∶1.5)were used as raw materials,with probiotics powder used as the control.An advanced dynamic in vitro gastrointestinal model was employed to mimic the stomach and small intestine digestive environments present in children.The changes of gastric/intestinal pH,gastric retention ratio,apparent aggregation structure,and survival rate of total lactic acid bacteria(including Lactobacillus bulgaricus,Streptococcus thermophilus and Lactobacillus acidophilus)and Bifidobacterium lactis during the simulated dynamic gastrointestinal digestion were measured.The probiotics powder showed remarkably lower gastric pH and higher intestinal pH during digestion compared to the fermented milk samples.The aggregates formed during the digestion of fermented milk in the stomach gradually disappeared in intestine.The gastrointestinal survival of both the total lactic acid bacteria and B.lactis in all fermented milk samples was significantly higher than that in the solid drink(P<0.05).With the increase of casein/whey protein ratio,the gastrointestinal survival rate of the total lactic acid bacteria was significantly increased(P<0.05),but the viability of the B.lactis was not remarkably affected.These results suggested that casein micelles in fermented milk might have higher buffering capacity than whey protein and tend to form denser coagula or aggregates in the stomach.These might generate certain protective effect on probiotics,thus improving the survival of probiotics during gastrointestinal digestion.
作者
伍鹏
王娟
王晶晶
陈晓东
司徒文佑
段素芳
WU Peng;WANG Juan;WANG Jingjing;CHEN Xiaodong;SZETO IGNATIUS Manyau;DUAN Sufang(School of Chemical and Environmental Engineering,Soochow University,Suzhou 215123,China;Xiao Dong Pro-health(Suzhou)Instrumentation Co.Ltd.,Suzhou 215152,China;Inner Mongolia Dairy Technology Research Institute Co.Ltd.,Hohhot 010110,China;Inner Mongolia Yili Industrial Group,Co.Ltd.,Yili Maternal and Infant Nutrition Institute(YMINI),Beijing 100022,China)
出处
《食品与发酵工业》
CAS
CSCD
北大核心
2021年第12期147-153,共7页
Food and Fermentation Industries
关键词
发酵乳
酪蛋白
乳清蛋白
益生菌
存活率
胃肠道消化模型
凝聚物
fermented milk
casein
whey protein
probiotics
viability
gastrointestinal digestion model
coagulum
