Fermentation and the microbial community of Japanese koji and miso: A review

Area of Science:

• Food Science
• Microbiology
• Fermentation Technology

Background:

• Miso is a traditional Japanese fermented soybean paste, integral to Japanese cuisine.
• Its unique flavor, texture, and nutritional value are attributed to a complex microbial community.
• Current research on miso's microbiome is limited despite its importance.

Purpose of the Study:

• To review the two-stage fermentation process in miso production.
• To describe the known microbial communities involved in miso fermentation.
• To discuss potential health benefits and food safety considerations of miso consumption.

Main Methods:

• Literature review of existing studies on miso fermentation.
• Analysis of microbial roles in koji production (Aspergillus oryzae).
• Examination of secondary fermentation by bacteria and yeast.

Main Results:

• Miso production involves a two-stage fermentation: mold inoculation for koji, followed by bacterial and yeast fermentation.
• The specific microorganisms contribute significantly to miso's sensory and nutritional characteristics.
• Limited research exists on the detailed microbial dynamics throughout the fermentation process.

Conclusions:

• A comprehensive understanding of miso's microbial ecology is crucial for quality control and safety.
• Further research is needed to fully characterize the microbiome for optimized global production.
• Ensuring safe and delicious miso production requires continued investigation into its microbiological underpinnings.