Optimization Of Ginseng Fermentation Process With Lactic Acid Bacteria And The Protective Effect Of Rh1 On Cell Damage Induced By Glycidol

Ginsenoside is the main active ingredient in ginseng,which reflects the main physiological activity of ginseng.Ginsenosides include high-content ginsenosides such as ginsenosides Rb1 and Rg1,and some rare ginsenosides,such as ginsenosides C-K,Rh1,Rh2,Rh3,and Rg3.High-content ginsenosides are hydrolyzed(deglycosylated)to remove glycosyl groups and converted into rare ginsenosides.The fewer glycosyl groups it contains,the higher the bioavailability and pharmacological activity.Therefore,how to obtain rare ginsenosides has become the focus of scholars' s research.Researchers have tried to convert high-content ginsenosides into rare ginsenosides through various methods.Microbial fermentation is considered to be one of the safest and most efficient transformation methods.However,the research on the preparation of rare ginsenosides by microbial fermentation at home and abroad is still in its infancy.Lactic acid bacteria are common probiotics and are widely used as excellent fermentation agents.Screening lactic acid bacteria that are good for ginseng fermentation and can efficiently transform rare ginsenosides,optimizing ginseng fermentation transformation conditions,studing the multi-bacterial combination fermentation technology systematically,and using strains to coordinate fermentation to improve the conversion of rare ginsenosides and fermentation quality,those measures are of great significance both for the realization of the industrial production of rare ginsenosides and for the development of ginseng fermented foods and medical and health products.In this paper,the whole ginseng components were used as fermentation substrates,and 7 self-isolated and commercial lactic acid strains were used as fermentation agents.First,peptone,glucose and skimmed milk were used as a synergist,and the number of colonies and pH value of fermentation broth were used as detection indexes to optimize the fermentation conditions of ginseng whole components.The results showed that the best ginseng full-component culture medium composition was: sterile full-component ginseng homogenate(w):sterile water(v)=1:1,and peptone 1%(w/v).Under this medium condition,the number of colonies of Bifidobacterium,Streptococcus thermophilus and Lactobacillus plantarum reached the peak in the fermentation broth for 48 h,and the pH value of the fermentation broth was the lowest in 72 h.Taking the number of viable bacteria as the main evaluation index,a comparative test of single-strain fermentation and double-strain fermentation were conducted to determine the fermentation strain.The single factor test was used to optimize the culture conditions such as inoculation amount,initial pH and fermentation temperature.The response surface test was used to obtain the optimal conditions for the fermentation of compound lactic acid bacteria.The results showed that the combined fermentation of Lactobacillus plantarum KC-28 and Lactobacillus acidophilus LA-3 inoculation volume ratio was 1: 1,the optimum fermentation temperature was 37 ?,the initial pH was 6.8,and the inoculation volume was 3%.In order to verify the antioxidant activity of ginseng full-component fermentation broth,this article used the ABTS free radical scavenging rate,DPPH free radical scavenging rate,and hydroxyl free radical scavenging rate as indicators.It can be seen that the three kinds of free radical scavenging rates of the samples fermented by a single strain of Lactobacillus plantarum KC-28 or Lactobacillus acidophilus LA-3 were lower than the samples fermented by two strains.And with the increase of fermentation broth concentration,the free radical scavenging rates showed an increasing trend.The results showed that the combined fermentation of lactic acid bacteria had better ability to scavenge free radicals than single lactic acid bacteria,and enhanced the antioxidant capacity of the ginseng full-component fermentation broth.In this paper,ginsenosides were extracted from the ginseng fermentation broth after 72 hours of Lactobacillus plantarum KC-28 or Lactobacillus acidophilus LA-3 single fermentation and combined fermentation of the two strains.Using high performance liquid chromatography,We studied the effects of different inoculation fermentations on the conversion of ginsenoside Rd,Rg3,Re and ginsenoside Rh1.The results showed that the double-bacteria co-fermentation significantly improves the conversion of Rh1.In this paper,L-02 and HT22 were used as cell models,and glycidol was used as an oxidative damage agent to explore whether ginsenosides Rh1 and Rg3 have protective effects on glycidol-damaged cells.From the results,it can be seen that ginsenoside Rh1 at a concentration of 40 ?mol / L significantly increase the activity of L02 cells damaged by glycidol.