The Effect Of Prebiotics On The Survival Of Bifidobacterium Lactis Probio-M8 In Fermented Milk Based On Dynamic Bionic Digestive System In Vitro

Taking Bifidobacterium lactis Probio-M8 as the research object,the effect of prebiotics on Bifidobacterium lactis Probio-M8 in fermented milk was investigated.To study the effects of inulin,fructose-oligosaccharides,galactose oligosaccharides,konjac mannose-oligosaccharides and polyglucose on the proliferation and fermentation and storage characteristics of Bifidobacterium lactis Probio-M8 in the fermentation process,the dosage of each prebiotic was 1%,2%and 3%,respectively.The optimal addition amount of each prebiotic was selected by taking the live bacteria count as the main index and combining with the analysis of microrheology of fermented milk,and the living bacteria count,p H,TA,water holding capacity,viscosity value and texture characteristics of the storage period were comprehensively analyzed.A group of prebiotic fermented milk with excellent fermentation and storage characteristics and the control group were selected to analyze the gastric empting characteristics,and the improved Elashoff power index model equation was used to fit,and the gastric p H was dynamically monitored.Dynamic in vitro bionic digestive system test was conducted on fermented milk to analyze the effects of different prebiotics on the survival rate of Bifidobacterium lactis Probio-M8 in fermented milk.The results are as follows:(1)Compared with the control group,the active count of Bifidobacterium lactis Probio-M8 at the fermentation endpoint with different proportions of prebiotics in each group showed:The viable numbers of 3%inulin,3%oligosaccharides,3%galactose oligosaccharides,3%polyglucose and 2%konjac mannose-oligosaccharides were the highest in the same group,which were significantly higher than those in the control group(P<0.05),and increased by 0.74,0.53,0.50,0.26 and 0.37 orders of magnitude compared with the control group,respectively.At the same time,the microrheological analysis during fermentation showed that it had the fermentation characteristics of fast viscosity production,strong elasticity and good stability.(2)The optimal dosage of prebiotics in each group was carried out fermentation storage test.After storage at 4°C for 21 days,the survival rate of Bifidobacterium lactis Probio-M8in fermented milk in all groups was higher,and the viable number of Bifidobacterium lactis Probio-M8 in 3%inulin group was significantly higher than that in other groups(P<0.05).In addition,the viscosity of 3%inulin group was higher than other groups,and the texture analysis showed that the stability of 3%inulin group was the best.(3)The optimal dosage of prebiotics in each group was selected for dynamic in vitro bionic digestive system test.The determination coefficient r~2 of the fitting of Elashoff power exponent model equation of gastric emptying characteristics was>0.99,indicating a good fitting effect.The results showed that all the five prebiotics had positive effects on the survival rate of Bifidobacterium lactis Probio-M8 in fermented milk,and 3%inulin was the best after digestion,followed by 3%fructose-oligosaccharides,3%galactose oligosaccharides,2%konjac mannose-oligosaccharides and 3%polyglucose.The survival rates of 3%inulin in 60min stomach,120min stomach,60min small intestine and 120min small intestine were 81.3%,48.7%,44.0%and 24.0%,respectively,which were significantly higher than 75.0%,33.7%,34.0%and 13.0%in control group(P<0.05).In conclusion,compared with fructose-oligosaccharides,galactose oligosaccharides,konjac mannose-oligosaccharides and polyglucose,inulin addition can improve the number of viable bacteria and in vitro digestion survival rate of Bifidobacterium lactis Probio-M8 in fermented milk,which is conducive to its probiotic effect.