| Natto is a popular fermented soybean food product in Japan. Cultivar suitability for natto production is dependent on agronomic and seed quality traits as well as sensory properties. The objectives of this study were to evaluate: 1) agronomic traits of three types of natto soybean lines; 2) seed physical and chemical attributes of different types of natto soybean lines; and 3) sensory properties and their associations with agronomic and physical/chemical attributes. A total of 15 small-seeded genotypes including three superior, nine moderate, and three inferior natto lines were evaluated in a randomized complete block design with three replications at Keiser, Rohwer, and Stuttgart, AR in 2008 and 2009. Seed yield, maturity, plant height, and lodging data were collected. Harvested seeds were evaluated for seed size, hardness, water absorption, protein, oil, calcium, manganese, boron, and sugar content. In addition, seed samples from each plot were processed into natto for appearance, stickiness, flavor, texture, and shelf-life measurements. There were no significant effects of year, location, and genotype x location on agronomic and seed quality traits. The superior natto lines had significantly lower seed yields with softer texture, higher water absorption and sugar content, and lower protein plus oil, calcium, manganese, and boron content. In addition, natto sensory quality was found to be associated with several seed physical and chemical attributes. Desirable appearance, stickiness, flavor, texture, and shelf-life of natto showed positive correlation with sucrose and oil content, but negative correlation with seed hardness, protein, protein plus oil, calcium, manganese, and boron content. The results of this study can serve as indirect selection criteria in the development of superior natto cultivars. |
