低醇早酥梨酒褐变因子分析及其对挥发性香气化合物的影响研究

Analysis of Browning Factors in Low-alcohol Zaosu Pear Wine and Its Effect on Volatile Aroma Compounds

摘要:

为探讨低醇早酥梨酒贮藏期间褐变因子和挥发性香气化合物的变化，将早酥梨酒分别在4、25℃下避光贮藏60d，每隔7d测定PPO、POD、PAL酶活力，总氨基酸、还原糖、总酚、5-羟甲基糠醛质量浓度及褐变度，并采用SPME-GC/MS检测贮藏结束时的挥发性香气化合物。结果表明，早酥梨酒在贮藏期间POD活力下降速度极快，总氨基酸质量浓度、总酚质量浓度分别下降62%~70%和23%~31%，5-羟甲基糠醛质量浓度和褐变度不断增加。总氨基酸、总酚、5-羟甲基糠醛质量浓度及褐变度变化均符合零级动力学方程，且拟合效果良好。相关性分析显示总氨基酸、总酚与5-HMF质量浓度对早酥梨酒褐变的影响最大。贮藏60d后早酥梨酒中萜烯类、酯类、羰基化合物质量浓度有所增加，醇类、酸类化合物质量浓度显著降低；15种关键香气物质（OAV大于0.1）质量浓度与主要褐变因子之间的相关系数均大于0.8。研究结果对控制早酥梨酒褐变具有应用价值。

关键词:低醇早酥梨酒;挥发性香气化合物;动态模型拟合;非酶促褐变

Abstract:

The low-alcohol Zaosu pear wine was prepared and stored at 4℃ and 25℃ for 60 days respectively to investigate the changes in browning factors and volatile aroma compounds. The activity of polyphenol oxidase, peroxidase and phenylalanine ammonia lyase, and the content of total amino acids, reducing sugar, total phenols, 5-hydroxymethylfurfural as well as the browning degree were measured every seven days during the storage of wine samples. The volatile aroma compounds in pear wine were detected at the end of storage by using SPME-GC/MS. Results showed that the POD activity of Zaosu pear wine was rapidly decreased and the content of total amino acids and polyphenols was reduced by 62%~70% and 23%~31%, respectively. Meanwhile, 5-hydroxymethylfurfural content and browning degree were constantly increased during the storage of pear wine. The evolutions of total amino acids, polyphenol, 5-hydroxymethylfurfural and browning degree were perfectly fitted to the zero order kinetic equation. Correlation analysis showed that total amino acids, polyphenols and 5-hydroxymethylfurfural had a significant impact on the browning of pear wine. The content of terpenes, esters and carbonyl compounds was increased, while the level of higher alcohol and volatile fatty acids was significantly decreased in wine samples after 60 days of storage. The correlation coefficients between 15 key aroma compounds (OAV>0.1) and the main browning factors were greater than 0.8. The research results had potential application value for controlling the browning of Zaosu pear wine.

Key words:low-alcohol Zaosu pear wine;volatile aroma compounds;dynamic model fitting;non-enzymatic browning