In Vitro Fermentation Of Five Lactobacillus By Haw Pectin Oligosaccharides

In this paper,the pectin was extracted from haw fruit,and four different degrees of haw pectin oligosaccharides were prepared through the decomposition of pectinase.Five strains of Lactobacillus probiotics were further selected to study their effects on fermentation of haw pectin oligosaccharides in vitro and the influencing factors.The main results are as follows:?1?Pectin was extracted from haw by hot water.The yield of haw pectin was 10.1%.Pectinase was used to hydrolyze haw pectin to prepare 4 kinds of haw pectin oligosaccharides with different average degree of polymerization.Oligosaccharides with an average degree of polymerization of 7,5,3.2 and 2.5,respectively.?2?In vitro fermentation of haw pectin oligosaccharides using Lactobacillus bulgaricus,Lactobacillus plantarum,Lactobacillus rhamnosus,Lactobacillus casei and Lactobacillus delbrueckii.The results showed that five strains of Lactobacillus can grow.Haw pectin oligosaccharides showed a certain concentration dependence.That is,as the concentration of oligosaccharides increased,the growth of five Lactobacillus strains showed a gradual upward trend,manifested as the density of bacteria in the fermentation broth,the OD₆₆₀ value gradually increased.Among them,Lactobacillus bulgaricus and Lactobacillus plantarum are in a 1%fermentation broth of haw pectin oligosaccharide,Lactobacillus rhamnosus and Lactobacillus delbrueckii in a fermentation broth with an oligosaccharide concentration of1.5%.The bacterial density is the highest,while Lactobacillus casei reaches a maximum at the oligosaccharide concentration of 2%.?3?Results of studies on the effect of initial pH of the fermentation environment on the fermentation of haw pectin oligosaccharides by Lactobacillus bulgaricus,Lactobacillus plantarum,Lactobacillus rhamnosus,Lactobacillus casei and Lactobacillus delbrueckii.It was shown that the initial pH of the fermentation broth did not have a significant effect on the growth of five strains of Lactobacillus in the range of initial pH 5.5-7.5.?4?The degree of polymerization of haw pectin oligosaccharides showed a great influence on the growth status of five strains of Lactobacillus.For Lactobacillus rhamnosus and Lactobacillus casei,the lower the degree of polymerization of haw pectin oligosaccharides is,the more favorable it is for growth;the growth of two Lactobacillus species in the treatment of haw pectin oligosaccharide?S4?with a degree of polymerization of2.5.The state is best,and its prebiotic value is also the largest,reaching 55.4%and 65.02%,respectively.The growth status of Lactobacillus bulgaricus,Lactobacillus plantarum and Lactobacillus delbrueckii in the haw pectin oligosaccharide?S3?group with a degree of polymerization of 3.2 was the best,and the prebiotic values were 60.5%,60.1%and 57.5%,respectively.?5?The results of five lactobacillus fermented oligosaccharides producing short-chain fatty acids were examined.The results showed that the metabolism of haw pectin oligosaccharides by the Lactobacillus bulgaricus has strong acid production ability,while Lactobacillus plantarum and Lactobacillus rhamnose has a weak ability to produce acid from the haw pectin oligosaccharides.In the 24h fermentation cycle,the total amount of short-chain fatty acids produced by fermented haw pectin oligosaccharides by Lactobacillus bulgaricus,Lactobacillus casei,Lactobacillus delbrueckii,Lactobacillus plantarum and Lactobacillus rhamnosus was 60.5 mmol/L,47.1mmol/L,46.2 mmol/L,38.9 mmol/L and34.7 mmol/L respectively.On the other hand,five Lactobacillus fermented haw pectin oligosaccharides producing different types of short-chain fatty acids.Among them,Lactobacillus bulgaricus,Lactobacillus casei and Lactobacillus delbrueckii metabolize haw pectin oligosaccharides with a relatively high proportion of lactic acid,while Lactobacillus plantarum and Lactobacillus rhamnosus produce relatively high proportion of acetic acid.?6?Further analysis of the structure-activity relationship of five strains of Lactobacillus fermented haw pectin oligosaccharides to produce short-chain fatty acids showed that there was a significant negative correlation between the amount of lactate,propionic acid and total short chain fatty acids produced by Lactobacillus casei fermentation and the average degree of polymerization.The amount of acetic acid fermented by Lactobacillus rhamnosus produced a significant negative correlation with the average degree of polymerization,whereas the ability of Lactobacillus bulgaricus,Lactobacillus plantarum and Lactobacillus delbrueckii to produce short-chain fatty acids and the degree of polymerization of haw pectin oligosaccharides did not was a clear linear relationship.The total short-chain fatty acids or lactic acid,acetic acid,propionic acid and butyric acid were all highest in haw pectin oligosaccharides with a degree of polymerization of 3.2?S3?.