Study On Wine’s Antioxidant Capacity And Wine’s Bound Volatiles

At present, wine antioxidant function and bound aroma attracted many studies. In this research, we focused on the capability of red and white wine to prevent cholesterol oxidation induced by free radical, the bound arom of wine and the wine parameters which affect the wine bound volatiles SPE extraction recovery.Moderate consumption of wine can reduce the incident of Cardiovascular diseases, platelet aggregation, stroke and some cancers, cause wine contain resveratrol and different kinds of pHenols, and their antioxidant and capability. So it is very necessary to prevent cholesterol oxidation inducing by free redicals, which will decrease the incidence of above disease and mortality. In this study, capabilities of Muscadine (MCD), Merlot (MLT), Cabernet Sauvignon red wine, Chenin Blanc and Sauvignon white wine in inhibiting cholesterol oxidation were evaluated using cholesterol emulsion (CE) system, a free radical generator, 2,2’-Azobis(2-methylpropionamidine) dihydrochloride (AAPH), was used to accelerate cholesterol oxidation at 37℃, the production of 7-ketocholesterol was detected after 0h, 24h, 48h and 72 h oxidation. In the research about white wine and red wine, the results show that Merlot and Cabernate Sauvignon red wines have the similary capability in reducing cholesterol oxidation reducing by free radical; and the Chenin Blanc and Sauvignon Blanc white wines have the similary capability of anti-cholesterol-oxidation, too; however, the red wines’activity are almost equal to 50 times of white wines’activity. The level of catechin in Merlot and Cabernate red wines are 140.6mg/L and 132.5mg/L, respectively; the resveratrol are 0.7 mg/L, 1.0mg/L, respectively; at the same time, the level of catechin in Chenin Blanc and Sauvignon Blanc are 10.6mg/L, 11.0mg/L, respectively; and the resveratrol level of the two white sample wines are 0.3 mg/L. also, the results demonstrated that the antioxidant capability of catechin are much stronger than the resveratrol’s capability. In the research about Muscadine and Merlot red wine, the results demonstrated that the both of sample red wines can strongly prevent cholesterol oxidation inducing by free radicals, meanwhile, the activity anti-cholesterol-oxidation of Merlot red wines is stronger than Muscadine red wines’; The mainly antioxidant compounds are catechin and anthocyanins, meanwhile, resveratrol was not determined, the content of anthocycanin in Muscadine and Merlot red wine are 150.1mg/L and 150.3 mg/L, respectively; and the content of catechin are 15.6 mg/L and 140.6mg/L, respectively. Compared with anthocyanins, catechin and resveratrol are more readily absorbed in the bloodstream without degradation after ingestion, it can be known that catechin rather than resveratrol may significantly contribute to the antioxidant capability of red wine in retarding cholesterol oxidation. Based on the results of those study, catechin level of normal table red wine is about 150 mg/L, consuming 60-70mL of the red wine would be helpful in inhibiting the oxidation of LDL cholesterol of a healthy person for 24 hours.The aromas of a finished wine are absent in many wine-grape cultivars (Vitis. L. vinifera), but are instead generated during fermentation and storage from non-volatile precursors such as the glycoconjugates. Glycoconjugates (glycosides) posses an aglycone covalently bound to one or four sugar moieties via an ether linkage. During wine production, glycosides may be hydrolyzed enzymatically by yeasts and exogenous glycosidases or non-enzymatically by acid-catalyzed hydrolysis. Following hydrolysis, the liberated aglycone can have immediate odor impact (e.g. linalool) or else may rearrange under acid conditions to form odor-active compounds (e.g.β-damascenone, 1,1,6-trimethyldihydronapHthalene). Cause the bound volatiles always effect on the wine’s desirable aroma, it is very important to determine the bound volatiles. In this research, the bound volatiles of wine was extracted by solid-pHase extraction (SPE), with LiChrolut EN polymeric packing resin, then those bound compound were hydrolyzed in water bath at 100℃. In Riesling white wine and Cabernet Sauvignon red wine, there are 37 and 36 different bound volatiles were identified. Those aroma compounds are grouped according to the biological origin of the precursors which presumably generated the volatiles, using this criterion, four large groups can be differentiated: lipid derivatives, norisoprenoid, terpenes and shikimic acid derivates. In generally, the different wine parameters: ethanol level, glucose, pH and tannin have the different response to those aroma compunds of SPE extraction recovery. In white wine‘Riesling’, when then ethanol level is between 3.75 mg/ml and 123.75mg/ml, ethanol is the most important parameter which affects SPE of bound volatiles recovery , the following is glucose and Glucose×Glucose; when the ethanol level decreased, between 3.75mg/ml and 63.75mg/ml, the ethanol is still the most important factor, the following is pH×Eth and pH; In Cabernet Sauvignon red wine, when the ethanol level is between 3.75mg/ml and 123.75mg/ml, ethanol also is the most important parameter which affects SPE of bound volatiles recovery, the following is ethanol×tannin and pH×tannin; when the ethanol decreased, between 3.75mg/ml and 63.75mg/ml, the ethanol is still the most important parameters, the following is Eth×Eth and pH. When the ethanol level is under 23.75mg/ml, there is no bound volatiles compounds will be effected by wine parameters. According to our study, we figured out the wine parameters affect the bound aroma’s SPE recovery; Meanwhile, a quickly, precise method was developed to detemine those wine bound volatiles.