Rice bran protein increases the retention of anthocyanins by acting as an encapsulating agent in the spray drying of grape juice

Abstract

Rice bran protein concentrate (RPC), an industrial by-product, may emerge as a green alternative for substituting animal proteins in microencapsulating compounds of interest. This study applied RPC, combined with maltodextrin (MD) as carrier agents, in the spray drying of grape juice, a product rich in these bioactive compounds, seeking to protect anthocyanins from degradation. The effects of carrier agent concentration [C: 0.75, 1.00, and 1.25 g of carrier agents (CA)/g of soluble solids of the juice (SS)] and RPC:CA ratio (P: 0%, as a control sample, 5%, 10%, 15%, and 20%) on anthocyanin retention and powder properties were evaluated. At 1.00 g CA/g SS, the internal and total retentions of anthocyanins improved by 2.4 and 3.2 times, respectively, when the RPC:CA ratio increased from 0% to 20%. The protein also exhibited excellent surface activity on the grape juice and positively influenced the physicochemical properties of the microparticles. There was a reduction in stickiness, degree of caking, and hygroscopicity, in addition to an increased antioxidant capacity when protein was used in combination with MD, especially at 1.00 and 1.25 g CA/g SS. Therefore, this study demonstrated that RPC could enhance the protection of anthocyanins during the spray drying of grape juice.

Keywords: Maltodextrin; Microencapsulation efficiency; Plant protein; Spray dryer.