The Antioxidant Activity Of Black Garlic And Its Effect On Lipid Level In Rats Fed With High-fat Diet

This paper used black garlic to analysis the change of chemical composition in the fermentation process and evaluation its antioxidant capacity in vitro.Establish the animal model of SD rats fed with high-fat diet,to explore the effect of black garlic water extract on blood lipid and liver lipid level,antioxidant capacity and representative intestinal microbes.（1）Using the variable-temperature fermented black garlic,the moisture,acidity were reduced,and the content of total sugar,reducing sugar,amino acids,polyphenols were increased compared with fresh garlic;Reducing sugar which significantly increased 36 times,to 452.72±24.63 mg/g;Polyphenols and S-allyl cysteine were fresh garlic 8 times,up to 9.53±0.59 mg/g,6.98±0.02 mg/g.Its material accumulation mainly occurred in the high temperature fermentation stage.（2）The results showed that black garlic had stronger antioxidant activity than fresh garlic.The IC₅₀of the DPPH·and OH·scavenging activity were 0.021 g/m L,0.036 g/m L and 0.012 g/m L,0.041 g/m L.When the concentration was 0.2 g/m L,black garlic total antioxidant capacity was fresh garlic 18 times;The effect of simulated gastrointestinal digestion on antioxidant capacity of balck garlic and garlic were researched.The results showed that:during digestion process,the polyphenol of the black garlic was decreased significantly（P<0.05）,and the fresh garlic was increased（P<0.05）.Similar to the total polyphenol,the total antioxidant capacity of balck garlic was decreased（P<0.05）,but the scavenging ability of OH·was increased（P<0.05）after simulated digestion.（3）Established the rats model with a high-fat diet,after 40 days,we found that high-fat diet rats had a higher TC、TG、LDL-C levels in liver and serum compared with normal-fat diet rats.When fed with 4g/kg black garlic extract for 40 days,liver weight reduced（P<0.05）,serum TC,HDL-C levels changed significantly（P<0.05）,liver TC,TG,LDL-C were significantly reduced（P<0.05）,showed that the supplement of black garlic extract could reduce the high-fat diet rats blood and liver lipid levels effectively;Its also could improve T-SOD activity,CAT activity and GSH content,decrease the liver MDA level,and enhance oxidation protection system of organism.（4）Compared with normal control group,the moisture content and PH value of high-fat diet rats were decreased significantly（P<0.05）,after adding black garlic extract,the moisture was increased（P<0.05）;During feeding,the number of Lactobacillus,Bifidobacterium,Enterococcus and Escherichia coli of control group were stable,and high-fat diet group Lactobacillus,Bifidobacterium and Enterococcus decreased significantly（P<0.05）,the balance of the intestinal microenvironment was destroyed.While the supplement of black garlic extract had not obvious impact on the number of gut microbes.