清香型白酒发酵过程中高级醇形成规律

Formation law of higher alcohols during the fermentation of light-flavor Baijiu

传统白酒发酵过程中高级醇的合成受到多种因素影响,该研究从环境(氧化还原电位)和物质(游离氨基酸)两方面探讨清香型白酒发酵过程中高级醇合成规律。结果表明,高级醇主要在发酵前期产生,随发酵进行呈现先增加后下降再增加的规律。发酵前期的高含氧量可能是推动高级醇大量合成的主要原因。16种氨基酸在发酵前期含量普遍较低,随发酵进行含量逐渐增加。游离氨基酸与高级醇之间的相关性结果显示,异戊醇、正丁醇、正戊醇、苯乙醇和丙醇与游离氨基酸呈现显著相关性。基于以上,推断高级醇的合成前期主要通过合成代谢途径(Harris pathway),随着发酵的进行,游离氨基酸大量产生,高级醇的合成逐渐转向氨基酸降解途径(Ehrlich pathway)。

The synthesis of higher alcohols was influenced by many factors in traditional Baijiu fermentation process.The effects of environment(oxidation-reduction potential)and substance(free amino acids)on higher alcohols synthesis during the fermentation of traditional light-flavor Baijiu were studied.The results showed that higher alcohols were mainly produced in the early stage of fermentation,which increased first,then decreased and increased again with the progress of fermentation.The high oxygen content may be the main reason to promote the higher alcohols synthesis in the early stage of fermentation.The contents of 16 amino acids were lower in the early stage of fermentation and gradually increased with the fermentation progress.The correlation between free amino acids and higher alcohols showed that isoamyl alcohol,n-butanol,n-amyl alcohol,phenylethanol and propanol were significantly correlated with free amino acids.Based on the above,it is inferred that the higher alcohols synthesis is mainly through the Harris pathway in the early stage and gradually moves to the Ehrlich pathway when the free amino acids are produced in fermentation progress.