Impact of air classification, with and without micronisation, on the lipid component of rice bran (Oryza sativa L.): a focus on mono-, di- and triacylglycerols

Rice (Oryza sativa L.) bran is an important by-product produced during the milling of brown rice, rich in several valuable compounds, such as lipids. Moreover, considering the valorisation potential of these material, the application of innovative and low-impact techniques can improve the overall quality of by-products for their future exploitation in the food manufacturing. In this study, the impact of air classification and micronisation (fine grinding) of rice bran on the lipid components was studied. These treatments allowed to obtain bran fractions, with different granulometry, from coarse to very fine. The total crude fat content was significantly higher in fine air-classified rice bran fractions. Besides, polyunsaturated triacylglycerols (TAG) were the most abundant compounds and monoacylglycerols concentration increased from ~15% in rice bran to ~22% in fine fraction. Considering the relevant emulsifying properties of these compounds, this fraction could be used as functional ingredient for the quality improvement of cereal-based products, without modifying the valuable fatty acid profile.