The role of canola, black caraway, and wheat bran protein isolates in anthocyanin microencapsulation via double emulsions

Abstract

This study investigates the potential of protein isolates from canola (Brassica napus L. var. napus) (CC) and black caraway (Nigella sativa) (NS) oil cake and wheat bran (Triticum aestivum) (WB) as sustainable alternatives to traditional soybean isolates (SB) for anthocyanin microencapsulation in double emulsions, aiming to leverage agricultural by-products for sustainable food processing, potentially offering improved functionality for sensitive compound stabilization. The study discovered that NS concentrates considerably improved emulsion stability (ES) (75.89 %, 77.26 %, 85.09 %) in samples when compared to other isolates. SB produced the lowest (1.17 span) and most consistent droplet diameters. Each of the protein isolates under investigation exhibited commendable efficiencies in the encapsulation of anthocyanins. However, the isolates derived from soybean distinguished themselves by achieving the highest encapsulation efficiency, suggesting that they possess intrinsic properties that may not be fully paralleled by the alternative protein sources examined. FT-IR spectroscopy revealed varied secondary structural compositions among the isolates, corresponding to their functional capabilities in emulsion system. This study helps to generate innovative functional foods and fosters the circular economy by successfully encapsulating and stabilizing anthocyanins.