Recovery of protein from brewer's spent grain by ultrafiltration

Application of ultrafiltration in recovery of protein from brewer's spent grain (BSG) was studied in this work. The effectiveness in removing water and salts was evaluated. Results indicated that increasing of cross-flow rate could improve the limiting flux. More than 92% of the protein was retained by the membranes with both MWCO of 5 and 30 kDa. The protein contents in the final product were 20.09 ± 1.40% and 15.98 ± 0.58%, respectively by 5 and 30 kDa membranes compared with that of 4.86 ± 0.61% concentrated by rotary evaporation. It indicated that ultrafiltration had good ability in the removal of salts in the extract solution and improved the quality of final products. The 5 kDa membrane had a little higher protein retention capacity than that of 30 kDa.