Antioxidant Activities Of Yellow Wine And The Involvement Of Phenolic Compounds

Yellow wine, beer and red wine are the three most ancient wines in the world. Traditionally yellow wine, derived from Shaoxing China, is brewed from glutinous rice and wheat Glutinous rice contains higher protein, lower fat, and the wheat can ofifer abundant carbon, nitrogen and microelement source for mold and yeast used for fermentation. The unique brewing technology handed down from generations brings yellow wine with bright brown color, subtle sweet flavor and low alcoholicity. Therefore yellow wine has been popular in China for centuries and was honored as the national banquet wine. In addition, yellow wine is widely known for its health care function. It is not only a good tonic, but also frequently used in Chinese traditional medicine as therapeutic component and has been claimed to have beneficial effects on the prevention of cancer and cardiovascular disease, but there is no epidemiological evidence.In this study, the antioxidant activity of yellow wine and its concentrate and volatile compounds was determined in terms of total antioxidant, reducing capacity, free radical scavenging, metal chelating and superoxide anion radical scavenging activities. These various antioxidant activities were compared with synthetic antioxidant, such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT). The total phenolic compounds were also determined. Results indicated that yellow wine and its concentrate exhibited similar strong total antioxidant activity. The inhibition percentage of 100 μl of yellow wine and its concentrate on peroxidation of 2.5 ml of linoleic acid emulsion was 97.99% and 95.74%, and both of them also had effective reducing capacity, 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging and superoxide anion radical scavenging activities, but had very low metal chelating activity on ferrous. However, the volatile compounds in yellow wine had little antioxidant activities. Results indicated that active antioxidants were non-volatile and resided in the concentrate after evaporation. Phenolic compounds may play a very important role in the antioxidant function.Then total antioxidant, reducing, free radical scavenging, and superoxide anion radical scavenging activities were determined in five Chinese rice wines (Guyuelongshan, Hongqu, Shousheng, Foshou, and Nuomi) comparing with synthetic antioxidants, such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene(BHT). Ten individual phenlic compounds including caffeic acid, syringic acid, and rutin, (-)-epicatechin, (+)-catechin, gallic acid, vanillic acid, p-coumaric acid, ferulic acid and quercetin, were identified and quantified by HPLC. Results indicated that rice wines exhibited high antioxidant power, and that total antioxidant activity, reducing capacity and free radical scavenging activity were highly correlated with total phenolic content Nuomi with the highest content of phenolic compounds showed the highest antioxidant activity, while Foshou had the lowest content with lowest activity. Syringic acid and (+)-catechin contributed most to the phenolic compounds and were highly correlated with all antioxidant properties (r2 > 0.75). However, vanillic acid, p-coumaric acid and quercetin showed little contribution to the antioxidant function.