Improvement of rice bran modified by extrusion combined with ball milling on the quality of steamed brown rice cake

Abstract

To improve the quality of brown rice food, rice bran modified by extrusion and ball milling was mixed with semidry ground rice flour to reconstitute brown rice flour, which was applied in steamed brown rice cakes. The physicochemical properties of modified rice bran and brown rice flour were investigated, and the quality of steamed rice cakes was evaluated. Compared with the single ball-milled rice bran, the rice bran modified by a combination of extrusion and ball milling had a smaller particle size (24.79 μm), stronger swelling (4.23 mL/g) and water holding (3.20 g/g) capacity, and higher nutritional value. Fourier transform infrared spectroscopy (FTIR) and x-ray diffraction (XRD) indicated that the crystal structure of starch was destroyed and amylose-lipid complexes were formed during the extrusion of rice bran. The reconstituted brown rice flour had a higher final viscosity and lower breakdown value than semidry ground brown rice flour, resulting in lower hardness, higher springiness of steamed brown rice cakes, and a specific volume that consequently increased by 21.71%. Hence, the processing of extrusion and ball milling effectively enhances the properties of rice bran, and the reconstituted brown rice flour is a prospective material for improving the quality of brown rice food.