Abstract
Even if freeze-dried natto is rehydrated in water, it loses much of its natto-like quality and cannot be successfully regenerated into natto. In order to be able to eat delicious natto even overseas, we have developed a rehydratable dried natto through industry-academia collaboration. The fermented natto was dried so as not to be subjected to secondary fermentation by blowing at 8-30°C, and then dried to a moisture content of about 7% that enables long-term storage by blowing at 20-80°C. Although this dried natto was very hard as it was, it had a natto-like character, and the cell number of Bacillus subtilis subsp. natto was as high as that of normal natto. By swelling with water at room temperature for 6 hours or at refrigerated temperature for 12 hours, it could be regenerated into natto as usual. Natto regenerated with water had more than twice the hardness of normal natto, and the degree of stringing was inversely proportional to the amount of swelling water.
