Purification Of Dihydromyricetin From Ampelopsis Grossedentata And Its Effect On Growth And Activity Of Lactic Acid Bacteria

Ampelopsis grossedentata is a widely used substitute tea spread in the mountainous areas of southern China.It is mainly made from the tender stems and leaves of Ampelopsis grossedentata after processing.It has the effects of clearing away heat and toxic materials,diminishing inflammation and swelling.Dihydromyricetin,the main active ingredient in Ampelopsis grossedentata,has been researched and developed by scholars since it was discovered in 1940.The current research results show that dihydromyricetin not only has the effects of scavenging free radicals,resisting oxidation,resisting thrombosis,resisting tumor and diminishing inflammation of general flavonoids,but also has the effects of relieving alcohol poisoning,preventing alcoholic hepatitis and fatty liver,inhibiting liver cell deterioration and reducing the incidence of liver cancer.It is a natural product that can protect liver,relieve hangover and sober up.Since Ampelopsis grossedentata was listed as a new resource food by the National Health and Family Planning Commission in 2013,people began to slowly try to add dihydromyricetin to food as a functional enhancer.This paper attempts to develop an efficient,convenient and low-cost way to purify dihydromyricetin from Ampelopsis grossedentata,explore the relationship between lactic acid bacteria and dihydromyricetin,and try to develop a new type of dihydromyricetin active yogurt.In this paper,Ampelopsis grossedentata was used as raw material,and the extract was pretreated by ethyl acetate extraction.The dihydromyricetin in the extract was purified by resin method.Taking the purity of dihydromyricetin as the index,four kinds of macroporous resins were selected for static and dynamic adsorption experiments.The results showed that in the static adsorption experiment,the adsorption capacity of HPD-100 macroporous adsorption resin for dihydromyricetin in the extract can reach 14.1mg/g,and the resolution rate can reach 87 %;In the dynamic adsorption experiment,HPD-100 macroporous adsorption resin was eluted by 30 % ethanol solution,and the eluent was concentrated and dried to obtain dihydromyricetin with a purity of more than95%.At the same time,its structure was analyzed by infrared spectroscopy and nuclear magnetic resonance spectroscopy,and the product was determined to be dihydromyricetin.In the experiment of exploring the relationship between dihydromyricetin and lactic acid bacteria,this paper preliminarily explored the effect of dihydromyricetin in Ampelopsis tenuifolia on the growth and activity of Lactobacillus acidophilus,Lactobacillus delbrueckii subspecies Bulgaria,and Streptococcus thermophilus by growth curve and flow cytometry.The results showed that when dihydromyricetin was added at100 ? 1 000 ?g/m L,it could significantly promote the growth of three lactic acid bacteria and increase the number of viable bacteria in their bacterial liquid(P < 0.05);When the addition of dihydromyricetin was more than 1 000 ?g/ml,the growth of three kinds of bacteria and the number of viable bacteria in the bacterial solution showed different degrees of inhibition,and Lactobacillus delbrueckii subsp.bulgaricus was the most sensitive to dihydromyricetin.In the analysis of bacteria liquid after fermentation,no obvious decrease of dihydromyricetin content was observed,which indicated that dihydromyricetin might affect the growth of lactic acid bacteria by adjusting the growth environment.In the development of dihydromyricetin active yogurt,orthogonal test was adopted in this paper.The effects of the addition of dihydromyricetin,sucrose and lactic acid bacteria powder on the quality of yogurt were investigated by using the acidity,water holding capacity and sensory evaluation of yogurt as indicators.The optimal process was obtained.The addition amount of dihydromyricetin is 0.14 ‰,the addition amount of sucrose is 8 %,and the addition amount of lactic acid bacteria powder is 0.20 %.At the same time,the protein content,fermented dihydromyricetin content and antioxidant activity of dihydromyricetin active yogurt were studied.The results showed that the protein content of dihydromyricetin active yogurt met the national standard,and dihydromyricetin had no obvious change before and after fermentation,and its antioxidant activity was significantly higher than that of ordinary yogurt.