Su Y.,Tianjin University of Science and Technology |
Su Y.,China National Research Institute of Food and Fermentation Industrials |
Yang L.,China National Research Institute of Food and Fermentation Industrials |
Hui L.,China National Research Institute of Food and Fermentation Industrials |
And 5 more authors.
Journal of the Institute of Brewing | Year: 2015
Bacterial communities in fermentative high-temperature Daqu play an important role in the Chinese roasted sesame-like flavour liquor brewing process. A culture-independent method of 16S rDNA clone library was applied to investigate the changes in bacterial diversity during the process of a Daqu fermentation. The results indicated that the types of bacteria species gradually increased with prolonged fermentation time. The first dominant bacterium, Pantoea sp. (73.68%), in the raw material was only detected at the beginning of the fermentation stage (8 days) in small quantities. The second dominant bacterium, Weissella sp. (16.99%) and the third, Lactobacillus sp. (4.57%), were both detected in the beginning fermentation sample (3.22, 11.29%), in the ripening fermentation sample (24 days; 6.89, 25.11%) and in the drying stage (49 days; 3.74, 7.47%). In the beginning fermentation, Thermoactinomyces sp. (47.57%) was detected as the first predominant bacterium, and it was also detected in the ripening fermentation stage (4.93%) and in the drying stage (15.68%). The bacterial communities in the Daqu fermentation process affected the physicochemical index of Daqu. A molecular analysis of the bacterial community from the Daqu fermentation process will benefit studies on the aroma production mechanisms from these bacteria. © 2015 The Institute of Brewing & Distilling.
Jiang Z.M.,Yantai University |
Chen Y.,Yantai University |
Wang D.L.,China National Research Institute of Food and Fermentation Industrials |
Wang X.L.,China National Research Institute of Food and Fermentation Industrials |
And 3 more authors.
Journal of the Institute of Brewing | Year: 2016
Solid-state fermentation is a unique technology used for Chinese liquor production and the porosity of the grain medium is one of the important characteristics in the process. However, research on the effects of porosity on flavour generation of liquor in fermented grains is rarely reported. Therefore the present paper introduces the concept of porosity from the field of soil studies and establishes a method for determining the porosity of the fermentation grain medium. Based on the practicality in liquor production, the influence of the addition levels of rice husk and the grinding intensity of the raw material on the porosity of the grain medium was studied. On this basis, the process of solid-state fermentation was simulated and the influence of different porosities on liquor flavour production was examined. The results showed that there were obvious differences in the flavour profiles of the fermented grains with different porosities. The most abundant content and species of volatile compounds appeared when the porosity of the fermented grain medium was ~33%. The development patterns of volatile flavour compounds, in both varieties and quantities, were examined in relationship to the porosity of the fermentation medium. Copyright © 2016 The Institute of Brewing & Distilling. Copyright © 2016 The Institute of Brewing & Distilling