Eco-Efficiency Assessment of Agri-Food By-Product Valorization: Integrating Profitability and Functionality in the Evaluation of Brewer’s Spent Grains Management

Brewer’s spent grains (BSGs) are the main by-product of beer production and are currently mostly undervalued. Offering an innovative perspective, this research examines BSG protein recovery for food applications as a novel route to more eco-efficient brewing. The weak functional properties of BSG ingredients are considered one of the main barriers to their use in food formulations. Alkaline extraction has been shown to improve those properties. An eco-efficiency assessment considering potential profits, environmental impacts, and additional quality and functionality indicators for BSG-derived ingredients in human consumption scenarios was performed to compare two types of BSG protein extracts with other common methods of BSG management (landfill, animal feed, and flour). Due to their improved functional properties compared to native BSG (mainly foaming and emulsifying capacities), extracts were more eco-efficient than other options when considering multiple values, while BSG flour was the most eco-efficient scenario when only profit was considered.