Impact of thermochemical pre-treatment and carbohydrate and protein hydrolyzing enzyme treatment on fractionation of protein and lignin from brewer's spent grain

Research output: Contribution to journalArticleScientificpeer-review


Research units

  • VTT Technical Research Centre of Finland


The aim of this study was to investigate how fractionation of protein and lignin from brewer's spent grain can be influenced by thermochemical and enzymatic pretreatments, including steam explosion, carbohydrase treatment and protease treatment. Following these pretreatments, protein and lignin were partially fractionated by alkaline extraction and acidic precipitation. Steam explosion and hydrolysis of cell wall polysaccharides substantially increased lignin solubilization and its recovery by acidic precipitation. Meanwhile, effective protein extraction required the use of protease, which increased protein solubilization from 15% to nearly 100% from otherwise untreated BSG. Steam explosion reduced the enzymatic protein solubilization but enhanced the extract recovery in the centrifugation step, presumably due to lower water-binding capacity of steam-exploded BSG compared to untreated BSG. Lignin and protein showed clear co-extraction and could only be partially separated by acidic precipitation, suggesting similar solubilities and strong interactions between these components. According to the results, protein and lignin are extractable from BSG after suitable pretreatments. This work provided increased understanding of the chemistry and interactions underlying the challenges in fractionation of BSG components.


Original languageEnglish
Pages (from-to)168-173
Number of pages6
JournalJournal of Cereal Science
Publication statusPublished - 1 Jan 2018
MoE publication typeA1 Journal article-refereed

    Research areas

  • Alkaline extraction, BSG, Protease, Steam explosion

ID: 32864134