氮源对低温发酵脐橙果酒挥发性成分的影响

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

为解决低温发酵周期长的问题,并进一步分析其挥发性成分。通过考察不同氮源质量浓度对低温发酵脐橙果酒酒精度和发酵时间的影响,确定氮源添加量,并采用顶空-固相微萃取-气质联用法(HS-SPME-GC-MS)分析其挥发性成分。结果表明,与未添加氮源的空白组相比,添加DAP 0.4 g/L、硫酸铵1.0 g/L、碳酸氢铵1.5 g/L的脐橙果酒酒精度可提高4.6%~5.3%,缩短发酵时间22%~56%。四种低温发酵脐橙果酒共检测出挥发性成分32种,其中高级醇5种、萜烯类化合物10种、中链脂肪酸2种、高级醇乙酸酯3种、中链脂肪酸乙酯7种、醛酮类5种。添加三种氮源的果酒中,萜烯类和乙酸酯类挥发性成分总含量均大于空白组,中链脂肪酸和乙基酯类挥发性成分总含量均小于空白组。其中,添加磷酸氢二铵的果酒中乙酸酯类挥发性成分总含量最高(1.170 mg/L),添加硫酸铵的果酒中萜烯类挥发性成分总含量最高(11.378 mg/L);与另外两种氮源相比,添加磷酸氢二铵的果酒中乙酸-2-苯乙酯、庚酸乙酯等挥发性成分含量相对更高,添加硫酸铵的果酒中D-柠檬烯、乙酸乙酯、癸酸乙酯等挥发性成分含量相对更高,添加碳酸氢铵的果酒中β-水芹烯、4-萜烯醇、辛酸乙酯等挥发性成分含量相对更高。实验证明了氮源对促进脐橙果酒低温发酵具有明显效果,并对挥发性香气成分含量具有一定的促进作用,为脐橙果酒低温发酵工艺的应用提供了理论依据。

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 ofβ-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.