NATTO HAVING IMPROVED SHELF STABILITY, AND MANUFACTURING METHOD THEREOF

摘要

PROBLEM TO BE SOLVED: To provide a natto having notably improved shelf stability, while having sufficient quality as natto without deterioration of the quality; and a manufacturing method thereof.SOLUTION: The manufacturing method of natto having improved shelf stability includes: inoculating steamed soybeans or boiled soybeans with Bacillus natto; fermenting them in a temperature zone of 37 to 53°C; and performing heat treatment, with the bean product temperature kept in a temperature zone of substantially 54 to 67°C for 3.5 hours or less. The natto manufactured by the method satisfies both of the following conditions immediately after the heat treatment: (A) free amino acid content is 14.5 mg/g-natto or less; (B) γ-PGA content is 1.1 mg/g-natto.