NMR Spectrum Analysis And Its Antioxidant Activity Of Dry White Wine

Wine is produced using fresh grape or grape juice as raw material after alcohol, called bee wine. Compared with dry red wine, there is little study of dry white wine. In recent years, with the rapid development of the wine industry, there are more and more attentions to the dry white wine. This paper researched the relationship of the environment conditions and growth of the four grape:White Riesling、Semillon Blance、longya、Sauvignon Blance. In the experiment, four dry white wines were fermented under low temperature. Experiment measured and analysed Brewing technology、physicochemical property and sensory quality. Compared the metabolites of the four dry white wine using NMRS. The purposes of this study were comprised the assessment of the scavenging effect (on DPPH) of dry white wine samples by ESRS. The conclusions are as follows:1. The Brix of vitis vinifera in mature wine grapes can be up to210g/L. The geographical condition of Sungod has the ability to produce the high-quality wines.2. Chose the high quality yeast:VL2VIN BLANCE Saccharomyces cerevisiace that imported from France. In addition, the production process used low-temperature fermentation (18-20℃) which was made for dry white wine of quality. All indices of the dry white wine were in accord ance with the standard of the GB15809-2006. Its quality was stable. The flavor and quality of dry white wines which producted in different years were similar.3. The direct analyses of the wine presented some limitations for the detection of "minor" compounds:amino acids, phenolic compounds, etc. So in this paper, chosing the NMR spectrum of the wines with freeze-drying and water-squelched for comparison and analysis.4. According to one-dimensiona(1D)1H NMR spectra of Sauvignon Blance, the assignments of the metabolites have been carried out on the basis of the analysis of2D NMR and spiking experiments and of information published elsewhere. Some metabolites were identified.Lactic acid was not observed wines because these wines were not fermented by ML bacteria, which converted malic acid to lactic acid.5. The amount of dissimilarity was obvious between the dry white wines vinified in different years, but wasn’t obvious between the dry white wines vinified with different grape varieties. There was higher similarity between Semillon Blance vinified in2008and2009. Comparatively speaking, the amount of dissimilarity was obvious between the dry white wines vinified with Longyan grape and others. This demonstrates the possibility of NMR-based metabolomic research to characterize wine quality and Product Country of Origin. 6. Randomly selected one dry white wine, choosing the best ESR measurement conditions by the study of wine antioxidant to study wine antioxidant capacity, the optimal conditions were the dilution factor of30times and reaction time of10minutes.7. For getting the clearance rate of DPPH by the peak area, this paper used Origin8.0and data analysis software. Different wines have different ability of removing DPPH, Sauvignon Blanc (2010) has the best ability of scavenge free radicals, it attained to68%. The total polyphenols content of Sauvignon Blanc (2010) was285.0mg/L8. The ability of removing DPPH was related with polyphenol content of dry white wine positively, but not a linear relationship. There were basically the same results with other conventional methods of determination of its antioxidant capacity. It was reliable results of ESR technique for the determination of antioxidant activity.