Study On Antioxidant Activity, Phenolic Compounds And Aroma Compounds In Kiwifruit Wines

Kiwi wine was fermented by five kiwi varieties（Qinmei, Huayou, Hayward, Yate, Xuxiang) and five yeast species in our laboratory. It showed the changing rules about antioxidantactivity and phenolic compounds during the fermentation and aging. The kiwifruit cultivarfitting for wine producing was selected by study the aroma character of kiwifruit wine ofdifferent cultivars. The main results of this paper are as follows:1.Yeast growth curve, the fermentation capacity of production capacity, testing, and thebrewing process of kiwi wine hypoglycemic rate and ethanol production capacity as well asthe original wine transmittance, chromaticity and polyphenols were analyzed. The resultsshowed that WLP775was the best one.2.Physical and chemical properties of five kiwifruits can meet the fruit wine brewingconditions, soluble solids content and pH value was14～18and3.42～3.75respectively.After the end of the main fermentation, soluble solids remained about5, pH was3.06～3.57.Five kiwi wines’ physical and chemical indicators (in addition to reducing sugar) did notsignificantly affect. Five kiwi wines showed strong antioxidant capacity, the change ofphenolic compounds can partly explain the changes of the antioxidant capacity of kiwi wine,but also some differences, which may require further study of other substances in the kiwiwine. For example, amino acids, peptides, maillard product. Total phenolic content varied,Qinmei kiwi wine had the highest content in the whole process.3.Caffeic acid and epicatechin as the main polyphenol content of2.106~2.417mg/L and0.643~1.831mg/L respectively; followed by ferulic acid and the original catechin content as0.543~1.108mg/L and0.429~0.861mg/L respectively; ellagic acid, catechins,proanthocyanidins B2content was relatively low, and catechin in Qinmei kiwi wine was notdetected, the Hayward wine did not detect the original catechin.4. The antioxidant capacity of the five kiwi wines after aging and the brewing processwas significantly different. Their total antioxidant capacity, reducing ability, DPPHscavenging capacity and superoxide anion scavenging capacity were a clear difference. Thelinoleic acid autoxidation inhibition rate of Qinmei, Huayou, Hayward, Yate and Xuxiang was76.5,74.1,70.9,72.5and69.7%, respectively. DPPH and superoxide anion scavenging capacity was in the order was almost the same. The order of reducing ability was Qinmei>Yate> Huayou> Hayward> Xuxiang. The total phenolic content Qinmei, Huayou, Hayward,Yate and Xuxiang were687,712,433,518and547μg.5. Volatile substances were alcohols, esters, volatile acids and other substances in five kiwiwines, which were15relative content greater than1%. The main aroma were similar, themain aroma were Ethanol, isobutanol, isoamyl alcohol, n-hexanol, ethyl acetate, isoamylacetate, ethyl caproate, hexyl acetate, ethyl octanoate, ethyl decanoate, caprylic acid. Thesimilarity of the main aroma and the difference of the minor aroma showed the kiwifruit ofdifferent cultivars had not only something in common but also their own characters.