Effect of Defatted Rice Bran Content on Physicochemical and Sensory Properties of Edible Cutlery Made from Rice Flour Green Composites using Compression Molding

Abstract

The optical properties, moisture content, water activity, water absorption, mechanical properties, morphological observations, and sensory properties of edible spoons made from rice flour and rice flour green composites were investigated. The rice flour green composites were prepared with different weight ratios of rice flour and defatted rice bran as 100:0, 75:25, 50:50, and 25:75 by compression molding at 150°C at a fixed pressure of 9 bar for 7 min. Increasing the weight proportion of defatted rice bran in rice flour green composites resulted in higher lightness values, yellowness values, and water absorption, but redness values and moisture content decreased. Weight proportions of defatted rice bran in rice flour green composites up to 50 improved mechanical properties (both Izod impact and flexural strength). The cross-sectional surface after flexural testing of rice flour spoons was smooth, whereas rice flour green composite spoons were rough. Sensory properties of rice flour green composite spoons showed reduced appearance scores, color scores, texture scores, and overall preference scores but odor scores increased compared with rice flour spoons. Maximum compression force of rice flour green composite spoons increased with increasing weight proportion of defatted rice bran. An increase in maximum compression force measured by the mechanical testing equipment was related to a decrease in texture scores. Spoons made from rice flour and rice flour green composites showed promise as single-use edible cutlery and packaging.