Study On The Interaction Between Acylated Purple Sweet Potato Anthocyanins And Intestinal Bacteria

Purple sweet potato anthocyanins have an acylated structure,and have a variety of physiological effects;this study on the interaction between anthocyanins and intestinal flora is conducive to understanding the influence of food components on the symbiotic relationship between intestinal flora and human body.Provides the basis for the development of healthy foods.The main research content is as follows:First of all,from the feces of healthy adult females,traditional culture methods were used to isolate and extract the four genus Escherichia call,Enterococci,Bifidobacteria,and Lactobacilli,and the best time for reaching the logarithmic phase was found by drawing the growth curve.Therefore,it is beneficial to the activation of strains and the effect of anthocyanin on the bacterial species.The linear relationship between the optical density and the colony-forming units(CFU)was determined.The antimicrobial activity of purple sweet potato anthocyanin extract was tested by the filter paper method.The results showed that the purple sweet potato anthocyanin had no inhibitory effect on the growth of neutral bacteria Enterococci;it had a certain inhibitory effect on the growth of neutral bacteria Escherichia coli,antibacterial The intensity of action increases with the increase of the purple sweet potato anthocyanin concentration.The maximum inhibition zone diameter reached 9.20(±0.26)mm when the anthocyanin mass concentration was 12.8 mg/mL.The results of in vitro cultivation of beneficial bacteria showed that purple sweet potato anthocyanin promoted the proliferation of Lactobacillus and Bifidobacterium,and the promoting effect of purple sweet potato anthocyanin increased with the increase of anthocyanin concentration of purple sweet potato in the medium.When the concentration of anthocyanins was 10.67 mg/mL,the A values of Lactobacillus and Bifidobacterium reached the highest,and anthocyanins had the most significant effect on the proliferation of bacteria.When the incubation time was 8-16h,anthocyanin accelerated the proliferation rate of Lactobacillus and Bifidobacterium.In comparison,purple sweet potato anthocyanin had a greater role in promoting proliferation of Lactobacillus.In this experiment,the monomeric anthocyanins of purple sweet potato were prepared by high-speed countercurrent chromatography.The effect of intestinal bacteria on peonidin-3-caffeoyl-feruloyl glucoside-5-glucoside was studied.Intestinal flora promoted the reduction of monomeric anthocyanin content to varying degrees,and the ability of intestinal microflora to degrade anthocyanins was greater than that of four mixed bacteria.The effect of a single bacterium on the anthocyanin of the monomer was studied.The ability of four bacteria to degrade anthocyanins was as follows:Escherichia coli>Bifidobacterium>Lactobacillus>Enterococcus.The degradation mechanism of anthocyanin in Escherichia coli was preliminarily studied by HPLC(520 nm and 280 nm)method comparative analysis.It is speculated that within the time frame of this study,the role of Escherichia coli did not cause the anthocyanins to undergo reactions such as hydrolysis or lysis,they were not degraded into smaller molecules.The UV-absorbing aromatic ring structure in the molecule was not destroyed as a whole,but the anthocyanin color-forming group was changed to form a colorless degradation product.This may be due to the fact that under neutral pH conditions,the action of Escherichia coli promotes the conversion of anthocyanins from blue or violet quinoid bases to partially colourless methanolic pseudo-alkaline forms which,over time,become such methanolic pseudo-alkali.The number of groups in the form gradually increased while the entire molecular weight did not change.