Bagasse produced in the brewing industry: Recovery and reuse alternatives

Abstract

Lignocellulosic waste is generated in many sectors of the agri-food industry and if these are properly processed, they can be used in industry to produce a variety of other high value-added products. Widely available waste is beer bagasse (spent brewery grain) which results from the maceration of the malt grain; it remains as the main waste covering around 85% of the waste generated. It accumulates in large amounts since world beer production in 2021 was 1.860 million hectoliters. Bagasse has a high moisture content and is composed of lignocellulosic biomass, with a significant content of proteins, fibres, lipids, ash, vitamins, amino acids, and phenolic compounds. Beer bagasse can be used as cattle feed, as it is rich in protein and does not cause digestive problems. It can be used as a functional ingredient in the food and pharmaceutical industry, providing fibre and protein to products. It can also serve as a substrate to produce biogas, enzymes and compounds in the food industry, or as food for insects, which in turn generate compounds for other products. Another use for bagasse is as a potential source of protein for aquafeeds, but it requires prior processing. It can also be utilised to make flour and enrich food products, providing nutritional and economic benefits. There are multiple ways to value this waste and there are still challenges to be addressed. The link between its production and uses aims to achieve the objectives of the circular economy.