鲜食葡萄白兰地蒸馏过程中主要发酵香气物质馏出动力学研究

以中国陕西主栽的鲜食葡萄户太8号为原料酿造葡萄白兰地,研究蒸馏过程中主要发酵香气物质的馏出规律。葡萄原酒自然澄清后进行一次蒸馏,摘除前3%的馏出液,随后进行二次蒸馏。在2次蒸馏过程中,利用GC-FID监测馏出液中果香酯、高级醇和脂肪酸含量,研究其蒸馏过程中的馏出动力学特征。采用感官量化品评法分析了蒸馏出的酒头、酒身、酒尾的气味特征。结果表明,在2次蒸馏过程中,大多数果香酯在起始阶段迅速累积后趋于稳定,并在前、中期停止累积；高级醇从起始阶段就有馏出,并持续至后期；而脂肪酸则主要在中后期馏出。分析发现,在第二次蒸馏进程的40%～60%阶段,主要发酵香气物质均有均衡馏出。感官分析表明,酒头辛辣味突出,酒身具有和谐的果香和醇香,而酒尾则有明显的蒸煮味。综合研究结果表明:户太8号葡萄蒸馏酒的较佳蒸馏工艺是摘除一次蒸馏的前3%馏出液,再将剩余部分进行二次蒸馏；二次蒸馏的前2%～5%作为酒头,80%～100%为酒尾,其余为酒身。研究结果可为葡萄白兰地蒸馏过程中的摘酒工艺提供技术指导。

Research on Distillation Kinetics of Major Fermentative Aroma Compounds During Distillation of Table Grape Brandy

Grape brandy brewing was carried out using the table Hutai-8 grapes, primarily cultivated in Shaanxi, China. Distillation characteristics of the main fermentation aroma compounds during distillation process was investigated. After natural clarification of the grape wine, the first distillation was performed, discarding the first 3% of distillate, and followed by the second distillation. In both distillations, the content of fruity esters, higher alcohols, and fatty acids in the distillate were monitored using GC-FID to study the distillation kinetics characteristics during distillation. Sensory quantitative analysis was conducted to assess the aroma characteristics of the distillation head, heart, and tail. The results indicated that most fruity esters rapidly accumulated during the initial stages of distillation in two distillation runs, reached stability thereafter and ceased accumulation in the middle stages of distillation. Higher alcohols were distilled from the beginning to the end of distillation runs, while fatty acids were primarily distilled in the middle to later stages. Analysis reveals that during the 40% to 60% stage of the second distillation, the main fermentation aroma compounds were distilled, showing a relatively balanced distribution. Sensory analysis revealed a pronounced spiciness in the head, harmonious fruity and alcoholic notes in the heart, and a distinct cooked aroma in the tail. Overall, the optimal distillation process for Hutai-8 grape brandy involved discarding the first 3% of distillate from the first distillation and conducting the second distillation with the remaining distillate. The initial 2% to 5% of the second distillate could be considered as head, the final 20% as tail, and the intermediary portion as heart. These findings provided technical guidance for the distillation process of grape brandy, particularly in selecting fractions during distillation.