Recovery of antioxidative protein hydrolysates with functional properties from fermented brewer's spent grain via microwave-assisted three phase partitioning

The protein shortage for the world's population in the near future has prompted scientists to develop novel methods for the sustainable production of dietary proteins from various alternative sources. In this study, the application of the bioseparation technique known as microwave-assisted three phase partitioning (MATPP) was explored to simultaneously extract and separate proteins from brewer's spent grain (BSG) after fungal fermentation. The results of the study indicated that MATPP (82.2%) recovered twice the amounts of proteins from fermented BSG compared to three phase partitioning (TPP) (41.8%). Besides, no significant differences (p > 0.05) were observed in terms of amino acid composition, protein pattern, and some functional properties between the fermented BSG proteins (FBPs) obtained via TPP and MATPP. Additionally, MATPP was found to increase the antioxidant activities of FBPs. These findings suggest that MATPP holds great potential for industrial-scale protein recovery attributed to its effectiveness, simplicity, and speed. Microwave-assisted three phase partitioning (MATPP) is an emerging bioseparation technique that could simultaneously extract, separate, and partially purify proteins from protein-rich plant materials effectively within a relatively short timeframe. The fact that the microwave used does not significantly alter most of the physicochemical properties of the plant protein hydrolysates certainly supports the adoption of the technique in industry settings. MATPP demonstrates significant potential for industrial-scale utilization due to its efficiency, simplicity and potential cost reduction in production.