Study On Physical Properties Of Defatted Rice Bran-Crushed Rice Mixture

Rice bran and crushed rice are two by-product resources of rice with high yield and rich nutrition,but the rice bran is liable to rancidity and the morphology of crushed rice is poor,so they can't be used reasonably.In order to prolong the storage period of rice bran,firstly,fresh rice bran was degreased by ultrasound-assisted method.The defatted rice bran was mixed with the crushed rice flour to study the gelatinization,rheological and textural properties of defatted rice bran-crushed rice flour mixtures under different conditions.The study may provide a theoretical basis for the research and development of food with defatted rice bran and crushed rice flour as raw materials.The main results of this study are showed as follows:The optimum degreasing process by ultrasonic assisted method was determined with solid-liquid ratio of 1:17.5 g/mL,and ultrasonic wave power of 500W,and time of ultrasonic wave treatment 10 min.The result showed that the degreasing rate was much higher with 96.73%than that by traditional solvent extraction method.It could effectively control the increase of fatty acid value during storage period and prolong the storage period of rice bran.Secondly,compared with using defatted rice bran and crushed rice flour alone,adding defatted rice bran in crushed rice can make the mixing system show better gelatinization characteristics,and reduce the size of crushed rice powder properly can reduce the difficulty of gelatinization.Research shows that the cold paste of Binary Defatted Rice Bran-Crushed Rice Blend mixtures belongs to pseudoplastic fluid.adding defatted rice bran in crushed rice can reduce the apparent viscosity of the blending system,however,reducing the size of crushed rice powder or increasing the gelatinization temperature can increase the apparent viscosity of the blending system.In addition,When the crushed rice particle size is between 80 and 160 sieves mesh,the rheological properties of Binary Defatted Rice Bran-Crushed Rice Blend mixtures are related to the gelatinization properties.The analysis of texture characteristics shows that adding defatted rice bran or decreasing the diameter of broken rice powder can weaken the aging of the gel.The gel can not be formed under the condition of pH=3,meanwhile,the gel state is the best under that of pH=5,and the addition of salt or sugar can reduce the hardness of the gel.