Research On Mechanism Of Micro-Oxygenation And Its Application In Industrial Dry Red Wine-Making

Appearance of the micro-oxygenation(MOX) technique caused popular concern of many famous winemakers. In our modern industrial wine-making field, the stainless steel tanks are extensively utilized as wine aging container to replace expensive oak barrels. Oak barrels are characterized by permeability, allowing minute oxygen enter into barrel inside. However, the stainless steel tanks permits no incursion of oxygen, and do not satisfied with oxygen requirement of wine aging. Moderate oxygen is required, but excessive oxygen is disadvantageous to wine quality. Moreover, utilization of oak barrels went aganist protection of the precious forest resources. And it is unfeasible to extensively apply into practice due to its high costs and long period.The micro-oxygen technique create a micro-oxygen and mature environment ,similar to oak barrel, to wine by slowly and constantly suppling minute oxygen into the stainless steel tank, in order to satisfy the need of various oxygen-required physical and chemical reactions during wine aging ,and to improve and modify wine quality.The dynamic process of dissolved oxygen of wine in oak barrel and stainless steel tank was studied. The theoretical model of oxygen consumption was established,and its formula was represented by [DO]=[DO]*exp(-kox*t). The difference between oak barrel and stainless steel tank was evaluated.Under the conditions of industrial dry red wine-making, mechanism of micro -oxygenation was studied by analyzing the relationships among the amounts of oxygen, acetaldehyde, tannins, anthocyanin and so on. The result shows that the acetaldehyde content was adjusted precisely by regulation of oxygen supply. Participation of trace acetaldehyde can improve the formation of the polymeric anthocyanin derived from the free anthocyanin, and reasonable polymerization of tannins, in this way the quality of wine was greatly improved. The research on model wine shows that the effect of same microoxygenation treatment on the different type wine was different, and MOX is advantageous to the wine with stronger structure and higher tannins content.The micro-oxygenation technique was applied in industrial winemaking in our country for the first time. Different MOX treatments were carried out with the dry red wine (cabernet sauvignon) as trial material and 30000L stainless steel tank as trial container. Effect of MOX on various items was investigated systemically and completely, including the physical and chemical items, character of aroma, and organoleptic analysis. The concrete contents are as follows:1. The effects of MOX on alcohol content, residual sugar, extract, total acid, volatile acid, pH, malic acid, lactic acid and citric acid were not significant. The effects of MOX on total SO2 and free SO2 were significant. The total SO2 of Rck is higher than others, and TW2,TX2 is lower. The change trend of free SO2 is similar with total SO2.2. Ethyl acetate was slightly higher in the MOX treatment. Introducing minute oxygen into wine has a significant effect on the color of wine. Reasonable application of MOX can improve the color density of wine at 420nm, 520nm and 620nm.3. In this experiment, MOX has significant effects on tannins, HCl index, anthocyanin, polymerized index. Research shows that reasonable application of MOX can improve the felicitous polymerization of anthocyanin and tannins, in this way improving the quality of wine.4. By analyzing the aroma composition, there were 39 aroma substances in different treatments, and 12 aroma substances were all existed among them. There existed great difference with respect to aroma composition types, such as fat, alcohols, carboxylic acids, ketone, hydrocarbon compound and heterocyclic compound.5. Organolepic evaluation showed that the quality of TX2(oxygen 2 mg/L/month, oak 1 g/L) was the best, and NT(new oak barrel) second.Under the industrial production conditions, an ideal environment similar to oak barrel for wine can be created, by choosing the stainless tank as container, and adopting reasonable micro-oxygenation technique.