Extraction and Quantification of Lipids from Brewer’s Spent Grain and Its Potential for Lipase Production

Solid wastes from agro-industries may be used as culture medium for enzymes synthesis by filamentous fungi. The brewer’s spent grain (BSG) is generated in abundance in the south of Brazil. Currently, most of this waste is used for animal feed. This work aims to extract and quantify the lipid presents in this residue. The lipids extraction was carried out by Soxhlet extraction method. Initially, the brewer’s spent grain was maintained at 80°C for 30 minutes to remove the moisture. After, it was weighed a sample of 5 grams accurately. A flat-bottom flask, containing some glass beads, was dried at 80°C for 1 hour and it was weighed. The sample was introduced into the extractor unit in a sealed filter paper envelope. The solvent was added to flat-bottom flask (150 ml of ethanol). The scheme was assembled and maintained on a heating mantle for 4 hours. After, flat-bottom flask was maintained at 80°C for the complete solvent evaporation. Then, the flask was weighed again, to determinate the lipids mass presents in 5 grams of brewer’s spent grain. We can conclude that this study provides the basis for further studies, since the percentage of lipids present in this residue (8.6%) justifies its use in experimental tests that aim lipase production.