Effect of Nitrogen Sources on Volatile Components of Navel Orange Wine during Low Temperature Fermentation

To solve the problem of longer time during low temperature fermentation,and analyze its volatile aroma components. The concentrations of nitrogen sources was determined depending on the alcohol content and fermentation time of navel orange wine fermented at low temperature. The volatile components of orange wine samples were analyzed by HS-SPME-GC-MS. The alcohol content of orange wine samples with 0.4 g/L DAP,1.0 g/L ammonium sulfate and 1.5 g/L ammonium bicarbonate added increased by 4.6%~5.3% compared with the no addition,and the fermentation time shortened by 22%~56%. The results of GC-MS showed that 32 aroma compounds were detected in four wine samples,including 5 higher alcohols,10 terpene compounds,2 medium-chain fatty acids,3 higher alcohol acetates,7 medium-chain fatty acid ethyl esters and 5 aldehydes or ketones. Compared with the no nitrogen source addition group,the three nitrogen sources group had higher content of terpenes and acetates,and lower content medium chain fatty acids and ethyl esters. The orange wine sample added with diammonium hydrogen phosphate had the highest content of acetate compounds(1.170 mg/L),while the orange wine added with ammonium sulfate had the highest content of terpene compounds(11.378 mg/L). 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 β-phellandrene,4-carvomenthenol and ethyl caprylate in orange wine added with ammonium bicarbonate was relatively higher. The result showed that nitrogen sources had significant effect on promoting the process of low temperature fermentation,and had effect on promoting the content of some volatile aroma components. This study provide a theoretical basis for the application of low temperature fermentation technology on orange wine.