Quality properties of defatted rice bran extract powder and vegan cookies

This study aimed to enhance the value of defatted rice bran, a byproduct of rice milling, as a sustainable food ingredient. Defatted rice bran extract powders were obtained by water, autoclave, alcalase, and autoclave/alcalase treatment, and their quality characteristics were investigated. The extract powders treated with alcalase and autoclave/alcalase showed higher contents of protein (19.34-22.86%), essential amino acids (6.22-7.44%), and branched-chain amino acids (2.67-3.18%). The autoclave/alcalase-treated extract powder exhibited the highest amino acid score (0.94), in vitro protein digestibility (90.67%), and protein digestibility-corrected amino acid score (0.86). The extract powder showed higher oil absorption capacity and water solubility index but lower water absorption capacity compared to wheat flour. Vegan cookies prepared with 7%, 13%, 20%, and 27% of autoclave/alcalase-treated powder had a lower spread ratio, loss rate, and leavening rate than control cookie, with a firmer texture, lower elasticity, and a darker red color. Sensory evaluation results showed that the vegan cookie with 20% extract powder received higher scores in appearance, aroma, taste, texture, and overall preference. Therefore, defatted rice bran extract powder can be applied in the food processing industry, particularly in vegan bakery products, as a source of high-quality protein.