Characterizing Soy Sauce Moromi Manufactured by High-Salt Dilute-State and Low-Salt Solid-State Fermentation Using...

Area of Science:

• Food Science and Technology
• Microbiology
• Biochemistry

Background:

• Moromi fermentation is crucial for traditional food production.
• Different fermentation methods, such as high-salt dilute-state (HSDS) and low-salt solid-state (LSSS), influence moromi characteristics.
• Understanding microbial dynamics and chemical profiles is key to optimizing moromi quality.

Purpose of the Study:

• To characterize physiochemical properties, free amino acids (FAAs), volatiles, and microbial communities of HSDS and LSSS moromi.
• To investigate the impact of fermentation stages on moromi composition.
• To compare the sensory profiles, specifically odor complexity, between HSDS and LSSS moromi.

Main Methods:

• Multiphase analysis including Phospholipid Fatty Acids (PLFA) and Denaturing Gradient Gel Electrophoresis (DGGE).
• Identification and quantification of free amino acids (FAAs) and volatile compounds.
• Odor activity value (OAV) analysis to assess sensory contributions.

Main Results:

• Gram-positive bacteria and fungi were dominant microbes, with shifts towards halophilic and acid-tolerant species during fermentation.
• Key dominant genera identified include Weissella, Tetragenococcus, Candida, Pichia, and Zygosaccharomyces.
• 15 FAAs and 44 volatiles were identified; LSSS moromi showed more complex odors than HSDS moromi.

Conclusions:

• Technological parameters, microbial communities, raw materials, and fermentation processes contribute to the differences between HSDS and LSSS moromi.
• Fermentation strategy significantly impacts the microbial ecology and volatile profiles of moromi.
• Further research can optimize fermentation for desired moromi characteristics.