Variation Of Antioxidative Activity In Brewing Persimmon Vinegar

Fruit vinegar is a kind of sauce, which fermented by yeasts, acetic acid bacteria using fruit or fruit juice as the main raw materials, its unique taste and excellent anti-oxidation activity are more and more attented by pepole. The conventional fermentation and the one-step fermentation were applied for producing persimmon vinegar with the persimmon as raw material, changes of its major components and anti-oxidation activity, as well as the correlation between them were studied in the process of fermentation, in order to reveal the variation regularity of antioxidative activity and material base, and provide theoretical foundation for processing persimmon vinegar and study of antioxidative activity.The conclusions of this study are as follows:1. The major components changes in the process of persimmon vinegar were determined in the conventional fermentation and the one-step fermentation. The results show that the content changes of soluble solids, reducing sugar and total sugar were similar in the two fermentation. Three of their content rapid decline in the during of pre-fermentation, and the content of soluble solids slow decline, and reducing sugar and total sugar content increase slightly in the aging stage. The total acid content rapid rises in the during of fermentation step and remains the same in the during of aging stage, both in conventional fermentation and one-step fermentation. Vitamin C, polyphenols and flavonoids content increased first and decreased in the fermentation stage, and rise slowly in the aging stage. But three of their content tend to decline in the early stage of aging in the conventional fermentation, and they maintain a balance in the early of aging and pre-fermentation in the one-step fermentation.2. In the conventional fermentation, the DPPH·radical scavenging rates changes little in the fermentation stage, but it increases significantly after 40 days in the aging stage, and the maximum scavenging rates is 64.92 percent in the end of aging stage; The hydroxyl radical scavenging rates of the persimmon vinegar rises from 57.72% to 79.59% in 4 days of the late in the fermentation period in the acetic acid fermentation stage, that the change is more obvious. But it maintains a balance in the aging stage. The total anti-oxidative capacity of persimmon vinegar remains elevated during in the fermentation and the aging, and the the maximum value 778.64mg Vc turns up in the end of aging.In the one-step fermentation, changes of the DPPH·and hydroxyl radical scavenging rate of persimmon vinegar both first increase and then decrease in the fermentation stage, and the DPPH·radical scavenging rate of persimmon vinegar rise slow in the aging stage. And the hydroxyl radical scavenging rate is expressed as a balance. In the period of 12 days of fermentation stage, the total anti-oxidative capacity of persimmon vinegar increases rapidly, from 111mg Vc in the pre-fermentation stage to 424.1mg Vc in the end of fermentation. And the upward trend of total anti-oxidative capacity slows in the aging stage until the end of aging as 610mg Vc.3. There is an extremely significant negative correlation between total acid and reducing sugar, total sugar, total phenol, total flavonoids in the conventional fermentation process(p<0.01), and a significant positive correlation between total phenols and reducing sugars, total sugar, total flavonoids(p<0.05). The hydroxyl radical scavenging rate of persimmon vinegar rate is related significantly with the total acid(p<0.05), and the total anti-oxidative capacity of persimmon vinegar are also related the total acid(p<0.05). In the one-step fermentation process, there is an extremely significant negative correlation among total polyphenols, vitamin C and flavone(p<0.01), and also does between total anti-oxidative activity and total acid(p<0.01). A remarkable positive correlation was also observed between the hydroxyl radical scavenging capacity(p<0.01), and the content of total polyphenols and among the DPPH·scavenging capacity of persimmon vinegar, the content of flavone, total acid and vitamin C(p<0.05).4. Persimmon vinegar can effectively scavenging the DPPH·radical and the hydroxyl radical. And the anti-oxidative activities of persimmon vinegar attribute to many kinds of components.