Brewers' spent grain as a food ingredient: Techno-processing properties, nutrition, acceptability, and market

Objectives: The study aimed to present the current trend during the 10 years study in the valorization of brewers' spent grain (BSG) derived compounds in food products from processing, nutritional improvement, and sensory acceptability. Results: The study discovered that BSG-derived compounds have been used in a variety of food products such as bread, cookies, baked snacks, pasta, noodles, muffin, yogurt, plant-based yogurt, ready to drink, confectionary, sausage, burgers, and mayonnaise. BSG flour was reported to reduce fat and sugar thus potentially as fat replacer and sugar reduction in food products. Several BSG-derived compounds in food products are reported including dried BSG flour, water fraction from fresh BSG, and protein hydrolysates. The main impact of BSG in food processing is its ability to modify the matrix formation of food products which at certain levels could diminish the textural properties thus negatively affecting the sensory acceptability. Several modifications have been made in order to improve the desirability of BSG-derived compounds in food products such as ingredients modification (e.g., sugar modification, oil vegetables, and others), utilizing pre-treated BSG (e.g., fermented, cooked, and extruded), and extraction of interest compounds (e.g., water fraction, protein, and BSG residue utilization). Conclusions: Although the evidence of BSG as a sustainable food ingredient has been clear, the study showed that lack of investigation was made in the commercialization approach such as big scale production and consumer familiarization on BSG-added food products which delay the feasibility of technological readiness and system readiness level.