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.
Protein concentrations in milk were compared using a modified Lowry and the micro-Kjeldahl methods. Correlation coefficients for absorbance (Lowry) vs protein (Kjeldahl) were 0.925, 0.904 and 0.899 for individual Holstein, individual Guernsey and bulk raw milk samples, respectively, whereas, the RZ was 0.9998 for samples of 2.5-4.0% protein prepared from three brands of nonfat dry milk. Added lactose, up to 16 mg/ml milk, did not interfere in the test. Storage at 4°C for up to 6 days was without effect. However, whey proteins had a lower specific absorbance than did casein. The standard deviation of differences among triplicate Lowry tests was about one-third of that for duplicate micro-Kjeldahl tests.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.