Some Alternative Strategies Applied to Brewery Spent Grains for the Development of Sustainable Recycling Solutions in the Agro-Food Industry

Abstract

Brewer’s spent grain (BSG) is a raw material produced during beer production that has a high potential for sustainable reuse. BSG is con­sidered an important feedstock for producing several products. Brewer’s spent grain (BSG) is the main by-product obtained after wort production commonly used as animal feed. Recently research work has focused on ap­plication in different areas, because of BSG’s low cost, large availability, and valuable chemical composition. Brewer’s spent grain forms 85% of the total by-products generated. Of the breweries that produce potential by-products, their recovery is an­other cost-effective pollution prevention option that can provide a facili­ty with significant economic benefits while simultaneously reducing waste production. BSG water content is around 80 – 85 %. Dry BSG content has around 60-63% hemicellulose, cellulose, and lignin, protein content is around 22-25%, lipids 8-9%, phenolic compounds 1.7-2%, ash 2.5%. In Albania spent grain is used as feed for animals without any other pre­treatment. Our experiment is focused on spent grain pretreatment and sta­bilization techniques to extend BSG’s life. BSG pretreatment/stabilization techniques can be employed as a function of their future destination such as energy production, food additives production, using BSG as a substrate for enzyme production, etc. In this paper, we have used three different pretreat­ment/stabilization procedures. Thin layer drying technique, alginate treat­ment of BSG, and vacuum filtration of BSG with cold and hot water. For each sample, we have monitored drying kinetics based on the remaining water content and BSG’s life.