Development of Soft, Sticky Itohiki-natto Manufactured for Senior Citizens

Abstract

With the increase in the proportion of older people in the population, the development of foods especially suitable for this segment of the population is eagerly expected. We produced a soft, sticky variety of natto that is easy for older people to masticate and to swallow, using a bacterial strain improved by mixed culture. By screening natto bacilli for their ability to make soft Itohiki-natto, we selected the strain Bacillus subtilis (natto) KFP 231, but the stickiness of the natto produced with this strain was very weak. Using a mixed culture of KFP 231 with Micrococcus luteus IAM+*/0, we obtained strain KFP 231++, which produced a soft, sticky natto. At approximately /., times that of KFP 231-natto, the relative viscosity of KFP 231++-natto was close to that of marketed natto. Similarly, the activity of the g-glutamyltranspeptidase of KFP 231 natto was approximately six times that of KFP 231++-natto. Analysis by capillary column gas chromatography detected the ten volatile substances that are responsible for the flavor of natto, showing that the flavor of KFP 231++-natto was similar to that of Japanese Itohiki-natto. Organoleptic tests were conducted on elderly subjects concerning the taste of the new soft, sticky natto at three o$cial centers for the elderly in Chiyodaku, Tokyo. The participants viewed the new soft, sticky natto as being slightly better than their generally held opinion of natto. Consequently, the newly developed soft, sticky natto proved to be a useful food for older people.

Correlation analysis between soluble sugars of soybean and mucus drawing length of fermented natto

“…In the sensory experiments of natto, the drawing performance of mucus is mostly used as the measurement standard (Cao et al, 2021;Yoshikawa et al, 2014;Yang et al, 2021). In a sensory test aimed at the elderly in Tokyo, participants rated soft, sticky natto as better than what they generally believed to be natto, and a newly developed soft, sticky natto proved to be useful as food for the elderly (Mitsuboshi et al, 2006). The good quality characteristics of natto depend on soybean varieties, processing conditions and strains.…”