| Polyphenols exist widely in nature and have high antioxidant activity.However,the direct utilization of polyphenols in the body is low.Generally,polyphenols need to be converted into small molecules with high activity by intestinal microorganisms before they can be absorbed and utilized to exert their anti-oxidant activity.Oxidation,polyphenols may be fermented by lactic acid bacteria,and the product activity may be increased.Therefore,this study aims to develop a polyphenol extract lactic acid bacteria compound fermentation beverage with strong antioxidant activity,and evaluate the efficacy of the beverage.In this study,the in vitro highthroughput antioxidant capacity screening model was used to screen the polyphenol and lactic acid bacteria strains with the strongest antioxidant capacity after fermentation.To improve the sensory quality and antioxidant capacity of polyphenol extract lactic acid bacteria compound fermentation beverage,a new type of polyphenol extract lactic acid bacteria compound fermentation beverage was developed;the efficacy and activity of the beverage were evaluated through cell models and animal models.Intervention effect of phenol extract lactic acid bacteria compound fermented beverage on oxidatively damaged cells and high-fat diet oxidative stress mice,providing a certain theoretical basis for the development and utilization of polyphenols.The specific results are as follows:Three polyphenols（grape seed proanthocyanidin extract,green tea tea polyphenol extract and tartary buckwheat flavonoid extract）and four lactic acid bacteria were used as research objects（Streptococcus thermophiles,Lactobacillus plantarum,Lactobacillus casei Lactobacillus casei and Lactobacillus bulgaricus）,using DPPH method,ABTS method and total antioxidant capacity（FRAP）as evaluation indicators to determine that Lactobacillus plantarum grape seed proanthocyanidin extract has the strongest antioxidant capacity,its DPPH clearance rate,ABTS The clearance rate and FRAP were 97.4%,62.9%,and 1.97,respectively.Using grape seed proanthocyanidin extract and Lactobacillus plantarum as raw materials,the fermentation process parameters were optimized by response surface model,and the optimal fermentation process parameters of polyphenol extract lactic acid bacteria composite fermentation beverage were determined.The optimized beverage has a higher sensory score,physical and chemical properties Characteristics,active substances and antioxidant capacity.Optimized process conditions are: grape seed proanthocyanidin extract 0.15%,skim milk 25%,drinking water 75%,Lactobacillus plantarum inoculation amount 4%,pectin 0.15%,acid-resistant sodium carboxymethyl cellulose 0.1%,citric acid 1%,White granulated sugar 6%,trehalose 2%,stevia 0.04%,fermentation temperature 37℃,fermentation time 23 h.The content of polyphenols in the polyphenol extract lactic acid bacteria composite fermented beverage reached 53 mg / 100 m L,the number of live bacteria in the beverage reached 3.5 × 108 CFU /m L,the protein content（g/100g）was 0.9,and the acidity was 86.6。T.The polyphenol extract lactic acid bacteria compound fermented beverage has high antioxidant capacity,and its DPPH and ABTS free radical scavenging ability are 79.1% and 65.2%,respectively.By establishing a model of oxidative damage to HepG2 cells,the effect of procyanidinlactic acid bacteria combined fermented beverages on oxidative stress was evaluated.The results showed that proanthocyanidin-lactic acid bacteria combined fermented beverages could significantly increase the oxidative stress of HepG2 cells（p <0.05）and significantly increase the total resistance of cells.Oxidative capacity（p <0.05）,significantly reduced MDA content in cells（p <0.05）,significantly increased glutathione content（p <0.05）,and significantly reduced the number of apoptotic cells.Procyanidins were fermented by Lactobacillus plantarum more than a single Proanthocyanidins and Lactobacillus plantarum have better antioxidation effect,and proanthocyanidins and Lactobacillus plantarum have a synergistic trend.A high-fat mouse model was established to evaluate the antioxidant effect of proanthocyanidin-lactic acid bacteria composite fermented beverage.The results showed that proanthocyanidin-lactic acid bacteria composite fermented beverage can enhance the scavenging ability of free radicals in serum and tissue of high-fat mice,and significantly enhance the antioxidant activity in tissue（T-AOC,SOD,CAT,and GSH indicators）,significantly reduce the MDA content in tissues（p < 0.05）,significantly increase the total antioxidant capacity of serum（p < 0.05）,and significantly reduce the lipid peroxide MDA content in serum（p < 0.05）.The antioxidant capacity of the polyphenol extract lactic acid bacteria compound fermented beverage group was significantly higher than that of the single probiotic anthocyanin beverage group and the plant lactobacillus beverage group,indicating that procyanidin fermentation by plant lactobacillus was better than the single polyphenol and lactobacillus plantus intervention.Antioxidant effect,procyanidins and Lactobacillus plantarum have synergistic interference.At the same time,proanthocyanidin-lactic acid bacteria compound fermented beverage can significantly reduce the abdominal fat index of mice,and can regulate the abnormal lipid metabolism induced by high-fat diet.The lipid indexes TC,TG,and AI index are significantly reduced（p <0.05）,which can significantly increase the intestine.The number of beneficial bacteria Lactobacillus and Bifidobacterium in the bacterial flora（p < 0.05）,and significantly increased the content of short-chain fatty acids acetic acid and butyric acid in the intestine（p <0.05）.In summary,this research has developed a new type of polyphenol extract lactic acid bacteria compound fermented beverage.This beverage has high antioxidant capacity and sensory evaluation.The functionality of this beverage was evaluated by an in cell model and an animal model.The results show that proanthocyanidin and lactobacillus plantarum in the proanthocyanidin-lactic acid bacteria compound fermented beverage have synergistic antioxidant activity and interfere with oxidative stress. |
