title: Pre-hydrolysis with carbohydrases facilitates the release of protein from brewer's spent grain.
abstract: Brewer's spent grain (BSG) is the most abundant side-stream from brewing. It is food-grade being rich in dietary fibre and protein and thus having potential as their source for both food and non-food applications. Initial treatment of milled BSG with a carbohydrase cocktail from Humicola insolens significantly enhanced the subsequent solubilisation of protein from the residual biomass. When treated with an alkaline protease, 76% of BSG protein was solubilized, whereas the yields were significantly lower with neutral or acidic proteases. In alkaline conditions significant amount of protein (53%) as predominantly low molecular weight protein was solubilized even without any protease addition. The degree of protein solubilisation was influenced by the time of exposure of modified BSG to the alkaline environment. The non-enzymatic protein solubilisation was, however, only observed when BSG had been initially treated with the carbohydrase, suggesting the protein is surrounded by cell wall polysaccharides restricting its initial release.
authors.affiliation: VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044 VTT, Finland. piritta.niemi@vtt.fi
authors.forename: Piritta
authors.initials: P
authors.lastname: Niemi
authors.forename: Duarte
authors.initials: D
authors.lastname: Martins
authors.forename: Johanna
authors.initials: J
authors.lastname: Buchert
authors.forename: Craig B
authors.initials: CB
authors.lastname: Faulds
mesh_terms: D001515:Beer; D018533:Biomass; D002473:Cell Wall / Q000378:metabolism; D002523:Edible Grain / Q000378:metabolism*; D006026:Glycoside Hydrolases / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007220:Industrial Waste / Q000032:analysis*; D007526:Isoelectric Point; D008970:Molecular Weight; D010940:Plant Proteins / Q000378:metabolism*; D012995:Solubility; D013696:Temperature; D013997:Time Factors
chemical_list: D007220:Industrial Waste; D010940:Plant Proteins; D006026:Glycoside Hydrolases; C019822:carbohydrase