Mechanisms of the regulation of ester balance between oxidation and esterification in aged Baijiu

Abstract

The influence of oxidation and esterification on the ester balance of aged Baijiu and methodology for the rational design of liquor flavors to optimize the practice of Baijiu production are not completely understood. We investigated the influence of ester balance on the flavor compounds of aged Baijiu by conducting constituent analysis of Baijiu from different aging times (0, 1, 2, 3, 4, 5, and 10 years). The changes of the main flavor compounds in the aging process were determined, and the correlations among different chemical reactions, such as oxidation, hydrolysis, and esterification, were systematically expounded. Furthermore, cluster analysis of the heat map indicated significant differences between aged Baijiu and new Baijiu and recommended a suitable aging time of 2–3 years.

Electrochemical esterification in distilled liquor via gold catalysis and its application for enhancing ester aroma of low-alcohol liquor

“…3 c. As seen, the content of lactic acid decreased steadily along with the increase of processing time of electrochemical treatment, while the content of ethyl lactate increased steadily along with the increase of processing time, which confirmed the transformation from lactic acid to ethyl lactate by the esterification process. In the earlier publication it was found that the spontaneous oxidation in the Baijiu aging process contributed to the increase of ester content ( Deng et al, 2020 ). The reaction rate of spontaneous oxidation, caused by the dissolved oxygen, is extremely slow, and a long period of time (at least three years) is required for the Baijiu aging process.…”

Volatile Compound Abundance Correlations Provide a New Insight into Odor Balances in Sauce-Aroma Baijiu

“…Fruity-like volatile compounds take an important part in the correlation network, including 2-butanol, ethyl propanoate, ethyl isobutyrate, ethyl hexadecenoate, isoamyl acetate, and isobutanol, which were all correlated to furfural, and the average abundance of these compounds in the RG group were all higher than that in the RP group. It is worth noting that due to the esterification and hydrolyzation balance of ester/acid in SAB [ 36 ], a close association between several pairs of ester/acid in the correlation network was noticed, for example, the correlation between acetic acid and ethyl acetate, and the correlation between butyric acid and ethyl butyrate.…”

Identification of Compounds Contributing to Trigeminal Pungency of Baijiu by Sensory Evaluation, Quantitative Measurements, Correlation Analysis, and Sensory Verification Testing

“…Ethyl acetate, one of the most abundant esters in Baijiu, 40 has a low boiling point and high volatilization. Because of the volatilization and the partial hydrolysis of ethyl acetate, the amount of ethyl acetate in Baijiu decreases rapidly with aging, 41 which could be associated with the decreased pungency and the improved smoothness with aging of Baijiu.…”