Digestive Properties Of Pasteurized Goat Milk And Its Effect On Gut Microbes

Goat milk is rich in nutrients and easy to digest and absorb,but it is extremely susceptible to contamination by microorganisms,causing spoilage and deterioration.Pasteurization can preserve the nutritional content of milk to the greatest extent,but there is still a certain amount of microorganisms in the milk,which has a certain impact on the quality and function of the product.This study investigated the effects of pasteurized goat milk quality,digestive characteristics,microbial diversity during storage,and intestinal microbial flora to provide a basis for the development and utilization of pasteurized milk.The first part is the effect of pasteurization on quality of goat milk.By researching the pasteurized goat milk(65?/30 min,72?/15s,85?/15s)at 4? for 1d,7d,14d,and 21d,its physical and chemical characteristics,microbial changes,and biologically active substances were studied.The results showed that the contents of protein,fat,lactose,ash content,and total solids did not change significantly during storage of pasteurized goat milk(P>0.05),but the acidity of goat milk increased with storage time;pasteurized goat milk The total number of medium colonies gradually increased with the extension of storage time;pasteurization had little effect on the contents of IGF-1,EGF,and cAMP in goat milk,but it could significantly reduce the contents of LTF and IgG in goat milk.The second part is the digestive properties of pasteurized goat milk.By researching the protein digestion of pasteurized goat milk(65?/30 min,72?/15s,85?/15s)using SDS-PAGE electrophoresis,the results showed that in the digestion of gastric juice,65?/30min pasteurized goat milk Protein is easier to digest than 72?/15s and 85?/15s pasteurized goat milk.Among the four caseins,asl-casein is easier to digest.In the intestinal digestion,65?/30min pasteurized goat milk is also easier than 72?/15s and 85?/15s pasteurized goat milk are easier to digest,and there is no significant difference in digestion of the four casein proteins.By comparing gastrointestinal fluid digestion,it was found that the protein in pasteurized goat milk digested in intestinal fluid was significantly higher than that in gastric juice.This shows that the protein in goat milk is mainly digested in the intestine.The third part is the study on microbial diversity in pasteurized goat milk.Through the study of microbial diversity during the storage period of pasteurized goat milk(72?/15s),the results showed that with the prolonged storage time of pasteurized goat milk,there were Verrucomicrobia?Verrucomicrobiae?Verrucomicrobiales?Enterobacteriaceae?Verrucomicrobiaceae?Bacteroidaceae?Yersinia?Serratia?Bacteroides?Parabacteroides?Akkermansia would continue to grow and reproduce,of which Yersinia?Serratia?Bacteroides?Parabacteroides belonged to harmful bacteria,which was the main bacteria group that caused the quality change of pasteurized goat milk,which should be paid attention to the actual production.The fourth part is the effect of pasteurized goat milk on intestinal microorganisms.Through the study on the effect of pasteurized goat milk(72?/15s)on intestinal microorganisms,the results showed that Firmicutes?Bacteroidetes?Muribaculaceae?Lactobacillaceae?Erysipelotrichaceae?Lachnospiraceae?Bacteroidaceae?Ruminococcaceae?Prevotellaceae?Rikenellaceae?Planococcaceae?Lactobacillus?Bacteroides?Dubosiella?Allobaculum?Alloprevotella?Turicibacter?Alistipes?Candidatus Saccharimonas?Kurthia?Ileibacterium in intestinal microorganisms was the dominant bacterial community.Pasteurized goat milk can promote Firmicutes?Erysipelotrichaceae?Allobaculum?Candidatus Saccharimonas?Ileibacterium?Paraprevotella?Desulfovibrio in intestinal microorganisms.It can also inhibit Bacteroidetes?Bacteroidaceae?Odoribacter?Rikenella?Enterorhabdus?Bacteroides?Intestinimonas in intestinal microorganisms.Pasteurized goat milk can promote the intestinal microbial community to participate in carbohydrate metabolism function,so as to improve the intestinal environment.