Isolation and identification of a blackAspergillusstrain and the effect of its novel protease on the aroma ofMoutai-flavouredliquor

Abstract

Among Chinese traditional distilled liquors, Moutai-flavoured liquor is the most famous, owing to its complicated process as it is derived from fermented sorghum coupled with the use of a Moutai-flavoured Daqu. In this study, a novel isolate, belonging to a black Aspergillus, was obtained and identified as Aspergillus hennebergii by ITS-5.8S rRNA sequencing analysis and conventional morphologic identification. The influences of initial pH, carbon source, nitrogen source and metal ions on the production of an A. hennebergii protease were studied. The results revealed that metal ions exerted a significant effect on enzyme production and activity. Additionally, the potential application of the protease from A. hennebergii was investigated. The enzymatic hydrolysis resulted in the identification and quantification of 42 compounds, including alcohols, aldehydes, pyrazines and esters. These volatile compounds exhibited special flavour properties. Significant differences were observed between the enzyme treatments and the control sample. Samples from the enzyme treatments led to the highest amounts of alcohols, pyrazines and aromatics. These results suggest that A. hennebergii, or its protease, may have some application values for the enhancement of the quality of Chinese liquor and for the improvement of the liquor production process.

Comparative characteristics of rice wine fermentations using Monascus koji and rice nuruk

“…However, the protease activity with M. koji was maintained at a higher level than with rice nuruk throughout the cultivation time. Thus, greater amounts of flavor and aroma compounds, which are partially derived from hydrolysis of proteins [23], were produced with M. koji than with rice nuruk.…”

Analysis of the mould microbiome and exogenous enzyme production in Moutai-flavor Daqu

“…Chinese liquors are among the world's oldest distilled alcoholic beverages and play an important role in Chinese culture and people's daily lives. Moutai liquor, a Chinese liquor, is distilled from fermented sorghum in the Guizhou Province of China . The combination of traditional technology, natural condition and advanced scientific process, Moutai‐flavor liquor is a unique product which is marketed in over 100 countries .…”

Investigating the Variation of Volatile Compound Composition in Maotai Liquor During Its Multi-Rounds Brewing Process Using Statistical Methods

“…The research includes microorganism composition analysis (1,2), the isolation and characterization of functional strains (3), fl avour component determination (4,5), and the analysis of the relationships between the microorganisms and fl avour compounds (6,7). However, the utilization of multiple fermentation and distillation steps, a very special technique for Maotai-fl avoured liquor manufacturing, has not received enough academic att ention so far.…”