Phenolic Composition Of Variety Wines And Commercial Wines And The Influence Of The Soaking Time With Grape Seeds On Phenolic Compounds In Wines

This thesis is divided into two parts, the first part is "research" separation and HPLC fingerprint of wine phenolics, established a high-performance liquid fifteen mono-phenols separation chromatography method in wine, wine polyphenols in main producing areas in China were determined by the composition and antioxidant capacity. To provide a theoretical basis for the objective evaluation of wine quality, to provide a reference for consumers. The second most "effect" in the process of wine fermentation seed of wine phenolics, mainly studied the fermentation process, influence of seed of wine phenolics. To provide a theoretical basis for the reform process measures of wine.The main research findings are as follows:(1) The contents of15mono-phenols in wines were determined using a dual-wavelength fusing HPLC method. The chromatographic separation was performed on a Waters XBridgeTM Shield RP18(4.6*250mm,3.5um) column at30℃with an acetonitrile/acetic acid/water mixture as a mobile phase at a flow rate of0.8mL/min. The injection volume was20uL, and the DAD detector was used at280nm and320nm. Under the optimal conditions, all15mono-phenols were successfully separated. The method showed good linear relationship, precision and repeatability. The contents of15phenolic acids in wines of different manufactures were also determined. The results showed that all15mono-phenols were found in red wines,13mono-phenols were found in white wines and14mono-phenols were found in Hutaibahao sweet wines. And the contents of several monophenols in red wines are higher than those in white wines, the contents of several monophenols in Hutaibahao sweet wines are the lowest. The results indicated that the method was accurate and reliable, and was suitable for the analysis of different mono-phenols in various wines. (2) Phenolic compounds and antioxidant properties of ten varietal wines from the Ningxia Helan zone of China were investigated. Results showed that grape variety affected greatly on phenolic composition and antioxidant properties of wines. For red wines, Cabernet Sauvignon represented the highest phenolic contents and antioxidant capacity. Amongst the white wines, Chardonnay and Chenin blanc showed the highest phenolic contents and antioxidant capacity. Phenol profiling of wines varied greatly among different grape varieties in both red wines and white wines. Moreover, the antioxidant capacity of wines appeared to be largely influenced by phenolic contents. Among the15individual phenolic compounds investigated in this study, a good correlation between (+/-)-Catechin hydrate, L-Epicatechin,(-)-Epigallocatechin gallate,(-)-Epicatechin gallate, quercetin, rutin, p-Coumaric acid, vanillic acid, gallic acid contents and resveratrol and the antioxidant activity was obtained while trans-Ferulic acid and gentisic acid had no contribution for antioxidant activity of wines.(3) This study selected Shaanxi market common wine samples, composition, color, the polyphenols antioxidant capacity were investigated, according to the assessment of the Shaanxi market wine quality. Analysis results show that, the Shaanxi market wine quality is generally good, but there are also individual products in the presence of exogenous gallic acid phenomenon. And simply rely on the tasters to assess the wine quality, limited to the professional level compared with the personal preferences, polyphenol composition, color, antioxidation parameters to evaluate the wine quality is feasible, effective method.(4) This study explored the effects of the time of eliminating grape seeds on antioxidant capacity and polyphenols composition of wine, through the analysis of different treatment methods, monitoring in fermented wine, grape, grape seed total phenolic content, total flavonoid content, total flavanol content, total anthocyanin content, fifteen kinds of monomers phenolic composition, DPPH free radical scavenging capacity, influence the basic clear grape seed to seed time on the antioxidant capacity of wine polyphenols composition and wine. To seed the time delay, the content of polyphenols and antioxidant capacity in wines increased,. By analyzing the monomeric phenols, indicating that the main source of catechin, epicatechin, chlorogenic acid, resveratrol is grape seed, coffee acid, ferulic acid, the main source of p-coumaric acid may be the grape skin.In the process of fermentation, the fermentation period, slower growth of monomeric phenols from grape seeds, in the middle stage of fermentation, after a period of time after soaking, grape seed testa gradually softened, monomeric phenols from grape seeds in the accelerated stripping. Monomeric phenols are derived from grape skins in dissolving speed, which may be related to the degree of fragmentation of the better. In addition to fermentation liquor on the extraction of polyphenols from grape seed and grape skins, the monomeric phenols in the fermentation liquor also changes in the complex, lead to the fluctuation of monomeric phenols.Compared with full fruit fermentation fermentation and broken, the polyphenol content, antioxidant capacity, only about half of the broken about fermentation, proves the necessity of breaking fermentation.