Alternatives to traditional valorisation ways for brewer’s spent grains

Brewer’s Spent Grains (BSG) are a highly available and cheap food supply chain waste (FSCW) that is mainly used in low-valued feed applications. This residue represents around 85 % of the total amount of waste produced by breweries with an annual tonnage of 3.4 million tons (on a dry basis) in the European Union. Based on its composition, BSG could be valorised in a wide variety of value-added products. For example, cellulose and remaining starch could easily be turned into ethanol or used as solid state fermentation media or as platform molecules for further chemical synthesis. These alternative valorisation ways could lead to an important economic relief through the whole brewery industry.
Herein is described a multistep fractionation of BSG into cellulosic pulp, free sugars, proteins, germs and lignin using an Organosolv acidic pretreatment. This extraction procedure has been optimised in order to allow the most efficient and complete valorisation of BSG.