Desired soy sauce characteristics and autolysis of Aspergillus oryzae induced by low temperature conditions during initial moromi fermentation

Autor: Jian Xiong, Chun Cui, Dongxiao Sun-Waterhouse, Wensi Zhou, Wei Wang, Keming Dong
Rok vydání: 2019
Předmět:
Zdroj: J Food Sci Technol
ISSN: 0975-8402
0022-1155
Popis: This is the first report on the effect of low temperature stress applied during initial moromi fermentation on the quality and taste of soy sauce. Koji was prepared to yield initial moromi under three comparative fermentation conditions over 9 days: (1) 4 °C and 0% brine (i.e., water) (LTSF); (2) 4 °C and 16% w/w brine (LTSH); (3) 25 °C and 16% w/w brine (the control, CRTH). Greater extent of autolysis in samples was found under low temperature stress conditions (i.e., at 4 °C, a temperature much lower than the normal temperature range like 25 °C for natural microbial growth and performance). Compared to CRTH, LTSF had a two-fold increase of glutaminase activity in dregs and 65.17% increase in supernatant, and after 60 days of moromi fermentation, a 5.73% and 3.47% increase, respectively, in the contents of glutamic acid (Glu) and aspartic acid (Asp). LTSF had the highest total free amino acid content due to both the low temperature stress and absence of salt. The intensity ranking of umaminess and kokumi sensation (LTSF > LTSH > CRTH) revealed by sensory analysis followed the changing trends of their umami and sweet amino acid contents with a trend reversal in the bitter amino acid content. Low temperature (4 °C) without brine for initial moromi fermentation seemed beneficial, leading to a soy sauce product with desired taste and amino acid contents. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s13197-019-03742-5) contains supplementary material, which is available to authorized users.
Databáze: OpenAIRE
Externí odkaz: