| Rice bran stabilization was conducted by internal (microwave), external (oven drying and steam retorting) heating and non-heating (;Two commercial rice varieties cultivated in Louisiana, one long grain (Lemont) and a medium grain (Nato), were milled to collect bran samples. The bran was analyzed for its proximate composition and various physical and thermal characteristics.;The proximate composition for long and medium grain bran, respectively, was: moisture, 11.2% and 10.8%; protein, 16.07% and 16.20%; fat, 19.20% and 21.97%; crude fiber, 8.49% and 8.41%; ash, 9.23% and 9.46%; and nitrogen-free extract, 47.01% and 44.07%. Physical and thermal properties for corresponding brans, respectively, were: bulk density, 18.20 lb/ft;The rice bran stabilized by four methods was packed in brown paper bags and stored in an extremely unfavorable environment (33 ;Heat transfer efficiency analysis revealed that microwave heating is superior to either external heating methods for bran stabilization. Multiple regression analysis indicated that the initial moisture content, weight of the rice bran and microwave heating time are three important variables for the inactivation of bran peroxidase and lipase. Given the microwave heating strength constant, optimum stabilization effect was obtained with 21% initial moisture content in rice bran. |
