Effect Of Low Temperature Fermentation On The Flavors Of Navel Orange Wine

Navel orange fruit wine is a flavor drink with nutrients of navel orange and certain alcohol content,and is one of the important directions for processing and utilization of navel orange resources.The aroma components of fruit wine are important indexes to reflect the quality.Enriching aroma components in fruit wine is of great significance to improve the quality.At present,the study of navel orange fruit wine is based on alcohol concentration mostly.It is brewed at the temperature that suitable for alcohol production,but cannot fully reflect the flavor characteristics of navel orange fruit wine.Low temperature fermentation is beneficial to keep the content of aroma components during fermentation,and promote the production of esters by yeast,which is of great significance for enriching aroma components and improving the quality of navel orange wine.The research take the navel orange as the study object,explored the parameters of navel orange wine during the low temperature fermentation.The efficiency of yeast was increased and the fermentation time was shortened by adding different nitrogen sources.The effects of different nitrogen sources on alcohol content,fermentation time and aroma components of navel orange wine fermented at low temperature were investigated comprehensively.By means of simultaneous fermentation at low temperature,the effects of Williams Saturnus on aroma components of navel orange fruit wine were investigated.At last,the antioxidant activity of navel orange wine fermented at low temperature was determined.The research provides a theoretical basic for improving the quality of navel orange fruit wine.The main results are as follows:(1)Through single factor experiment and response surface analysis,the optimal technological conditions of navel orange wine during low-temperature fermentation were determined which the fermentation temperature was 14?,initial sugar content was 22.3%and yeast the inoculation of Saccharomyces cerevisiae was 3.2%.Under these conditions,the total esters content of navel orange wine was 1.084 g*L.(2)By adding three nitrogen sources of diammonium hydrogen phosphate,ammonium sulfate and ammonium bicarbonate to the fermentation must,the alcohol content of navel orange wine was increased by 4.6%,5.3%and 5.2%respectively,and the fermentation time was shortened by 56%,44%and 22%respectively.The GC-MS results of navel orange wine showed that the aroma compounds identified in the wines were the same while the contents were different.Among them,the content of acetates in navel orange wine added with diammonium hydrogen phosphate was the highest(1.170 mg/L)compared with other experiment groups;The terpenes content in navel orange wine added with ammonium sulfate was the highest(11.378 mg/L)compared with other experiment groups.Compared with the other two nitrogen sources,the content of 2-phenyl ethyl acetate and ethyl heptanoate in orange wine added with diammonium hydrogen phosphate was relatively higher,the content of D-limonene,ethyl acetate and ethyl decanoate in orange wine added with ammonium sulfate was relatively higher,and the content of ?-phellandrene,4-carvomenthenol and ethyl caprylate in orange wine added with ammonium bicarbonate was relatively higher.(3)By means of simultaneous fermentation,the Williopsis saturnus to was used for low temperature fermentation.The alcohol content and total esters in navel orange wine showed the highest content,when the inoculation of Saccharomyces cerevisiae and Williopsis saturnus were 3%and 3.5%respectively.More aroma components were accumulated in the wine,and the proportion of terpenes and esters increased when Williopsis saturnus was applied to low temperature fermentation,(4)The total phenol content of low-temperature fermented navel orange wine was 0.464 mg/mL.The research of the antioxidant showed that the ability of clearing DPPH-was the low-temperature fermented wine>the normal temperature fermented wine>the market of orange wine,the ability of clearing the·OH was the market of orange wine>low-temperature fermented wine>the normal temperature fermented wine,the ability of clearing the superoxide anion was the low-temperature fermented wine>the normal temperature fermented wine>the market of orange wine.