Xianli Gao

TL;DR: In this article, the authors investigated the impact of koji fermentation on soy sauce aroma and found that 1-octen-3-ol, 3-octanol, di-epi-α-cedrene, benzeneacetaldehyde, 3-(methylthio)-propanal and 2-phenylpropenal were the major volatile classes present in koji samples.

TL;DR: In this paper, the authors investigated the impact of koji fermentation on soy sauce aroma and found that 1-octen-3-ol, 3-octanol, di-epi-a-cedrene, benzeneacetaldehyde, 3-(methylthio)-prop-anal and 2-phenylpropenal were the major volatile classes present in koji samples.

TL;DR: Nonprolamin fractions including proteins with structural functions or metabolic activities were extracted from barley malts of the widely used cultivars Gangpi and Baudin in China, suggesting important roles in barley malting and the mashing stage of brewing.

TL;DR: In this paper , the authors provide a comprehensive understanding of the formation mechanisms, the latest detection and control methods of BAs in traditional fermented foods, which might shed a new light on controlling and solving the problem of biogenic amines in traditional fermentation foods.

Abstract: Proximate indices, water soluble peptides distribution, free amino acids (FAAs) and aroma active compounds in soy sauces prepared using Aspergillus oryzae koji (SSAO) and mixed kojis (SSAON, A. oryzae koji: Aspergillus niger koji = 3:1, w/w) were determined. Results showed that SSAON resulted in 6.14, 5.97, 10.40, 71.59 and 9.62% of increases in contents of formaldehyde nitrogen, total FAAs, glutamic acid, peptides (≤1 kDa) and reducing sugar when compared with those in SSAO, whereas there were no significant differences in contents of aroma active compounds except for 2-methoxy-4- vinylphenol between these two kinds of soy sauces. The higher activities of acid protease, glucoamylase present in the mixed kojis, were the main reason for the increases of formaldehyde nitrogen, total FAAs, glutamic acid, peptides (≤1 kDa) and reducing sugar in SSAON. Moreover, results from sensory evaluation clarified that the taste of soy sauce prepared using mixture of A. oryzae koji and A. niger koji was obviously improved. Based on the results from the present study, soy sauce preparation using mixed kojis is an effective approach to improve its taste. Key words: Chinese-type soy sauce, Aspergillus oryzae, Aspergillus niger, free amino acid, aroma active compound.