Effect of Moisture Content on Physical Properties of Soybean

Abstract

Soybean (Glycine max (L)) is one of the oldest principal food crops and has paramount importance in Indian agricultural and oil industry. Soybean is recognized for its value in enhancing and protecting health. Soybean has a tremendous potential to be transformed into a number of traditional local foods. Different products can be prepared from soybean such as soymilk and soy-paneer (dairy analogs), soy flour, soy bakery products, soynuts etc.The physical properties of soybean are important to design the equipments and machines for sorting, separation, transportation, processing and storage. Designing of such equipments and machines without taking these into considerations may yield poor results. For this reason the determination and considerations of these properties become an important role. The major moisture-dependent physical properties of biological materials are shape, size, mass, bulk -density, true-density, porosity and static coefficient of friction against various surfaces. The study was conducted to investigate some physical properties of soybean at various moisture levels. The dependence of physical properties of soybean on moisture content was determined. In the moisture range from 9.98- 27.10% (wb).The soaked soybean size increased linearly in length (6.34 - 8.95 mm), width (5.42 -6.50 mm), and thickness (4.23 - 5.35 mm) according to final moisture content. In this study, length, width and thickness models based on moisture content are defined as linear models and the regression coefficients (R2) related to these models are found between 0.84, 0.72 and 0.70 respectively. Arithmetic Mean Diameter (5.330 - 6.933 mm), Geometric Mean Diameter (5.258 - 6.777mm), Square Mean Diameter (9.171- 11.876 mm), Equivalent Diameter (6.586 - 8.526 mm) are computed from the average values of three principal dimensions. In the current study, it was determined that unit volume (78.352-173.084 mm3), surface area (89.411-153.243 mm2), 1000 grain weight (120.2-132.432g) and angle of repose (25.25o-30.08o) increases as the moisture content of soaked soybean increases. As the moisture content of the soaked soybean increases, the value of sphericity, aspect ratio, bulk density, true density and porosity decreased.