Natto and miso: An overview on their preparation, bioactive components and health-promoting effects

Abstract

Natto and miso are two major traditional fermented soy foods in Japan. Natto is prepared by fermenting cooked soybeans with Bacillus subtilis natto. The beans of natto have a sticky outlook, slippery texture, sour aroma and nutty flavour. Bioactive components of natto are nattokinase, bacillopeptidase F, vitamin K2, dipicolinic acid and γ-polyglutamic acid. Miso is a fermented soybean paste widely used to make miso soup. The paste is produced by fermenting cooked soybeans with koji (steamed rice inoculated with Aspergillus oryzae). Bioactive compounds of miso include isoflavones and phenolic acids. In this review, the preparation, bioactive components, and health-promoting properties of natto and miso are highlighted. Sources of information referred were from Google Scholar, J-Stage, Science Direct, PubMed, PubMed Central and PubChem.