Multiple Parameter Optimization of Hydration Characteristics and Proximate Compositions of Rice-Soybean Extruded Foods

Abstract

Multi-parameter extrusion cooking conditions for the extrusion of composite flours of rice and soybean were modeled using response surface methodology (RSM). A five-level-three-factors central composite rotatable design (CCRD) was employed to optimize three process variables including barrel temperature (BRT)(X 1 ), feed moisture (FMC)(X 2 ) and feed soybean composition (FSC)(X 3 ) for the achievement of satisfactory hydration characteristics and proximate composition. The fitted polynomial models indicated significant coefficients, satisfactory coefficients of determination (R 2 and R 2 adjusted ) and non-significant lack-of-fit test. Optimum X 1 , X 2 and X 3 were 120˚C, 20%, and 23% for rice-soybean based extrudates. At these optimum combinations, optimum responses were 97.10% for dispersibility, 6.11 water absorption index and 8.42 water solubility index, while proximate composition of 1.02% moisture content, 3.62% lipid, 26.26% protein, 0.48% ash content, 2.14% fibre, 70.13% and 412.14 kcal/100g of energy were obtained. Under the optimized conditions, the responses are well matched with the predicted values and therefore the models could be used to predict the extrusion system in its natural state.

Optimization of barrel temperature and feed moisture content on physio-chemical and sensory properties of extruded snacks from finger millet, sweet potato, and soybean composite flour

“…This nding is consistent with the work of Adem et al [10], who found a rise in moisture contents of extrudates as the level of feed moisture content enhanced in maize-lupine extruded snacks. Maximum extrudates moisture was obtained at higher feed moisture contents (26%) due to high amounts of water in the dough [9]. The other probable reason is low vaporization, resulting in high feed moisture content since moisture acts as a lubricant that decreases the products' vaporization.…”

“…Product quality is signi cantly in uenced by the processing conditions of the extruder machine. Nahemiah et al [9] investigated the effect of feed soybean composition, barrel temperature, and feed moisture content on rice-soybean extrudates' nutritional quality and other characteristics. They found that feed soybean composition, barrel temperature, and feed moisture content signi cantly in uenced the extrudates' nutritional properties and other characteristics.…”