Protective ability against oxidative stress of brewers’ spent grain protein hydrolysates

• Published in: Food chemistry Vol. 228; pp. 602 - 609
• Main Authors: Vieira, Elsa F., da Silva, Diana Dias, Carmo, Helena, Ferreira, Isabel M.P.L.V.O.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.08.2017
• Subjects: Alcalase; Antioxidant activity; Brewer’s spent grain (BSG); Brewer’s spent yeast (BSY); Caco-2 cells; cytotoxicity; Edible Grain - chemistry; enzymatic treatment; grain protein; HepG2 cells; human cell lines; Humans; hydrolysates; iron; Neutrase; oxidative stress; Oxidative Stress - drug effects; protective effect; Protein hydrolysates; Protein Hydrolysates - chemistry; proteinases; proteolysis; spent grains; yeasts; Caco-2 cells; Protein hydrolysates; Antioxidant activity; Alcalase; Neutrase; Brewer’s spent yeast (BSY); HepG2 cells; Brewer’s spent grain (BSG)
• ISSN: 0308-8146; 1873-7072; 1873-7072
• DOI: 10.1016/j.foodchem.2017.02.050

•Brewers’ spent grain protein hydrolysates present in vitro chemical antioxidant activity.•Protein hydrolysates protected against oxidative stress in Caco-2 and HepG2 cells.•Hydrolysates from Brewers’ spent grain and spent yeast had strongest protective ability.•A potential functional ingredient was obtained from two major brewing by-products. The protein fraction of Brewers’ spent grain (BSG) was used as substrate to obtain hydrolysates with antioxidant activity. Three enzymatic approaches were applied: brewer’s spent yeast (BSY) proteases, Neutrase® and Alcalase®, at the same proteolytic activity (1U/mL), using an enzyme/substrate ratio of 10:100 (v/v), at 50°C, 4h. Total Phenolic Content (TPC) and Ferric Ion Reducing Antioxidant Power (FRAP) of hydrolysates and fractions <10kDa and <3kDa were assayed. Additionally, the protective ability of <10kDa fractions against oxidative stress on Caco-2 and HepG2 cells was investigated. Alcalase® hydrolysate presented significantly (p<0.05) higher TPC and FRAP (0.083mgGAE/mgdw; 0.101mgTE/mgdw, respectively) than Neutrase® and BSY hydrolysates. The three BSG protein hydrolysates (fraction <10kDa) exerted protective effect against free-radical induced cytotoxicity in Caco-2 and HepG2 cell lines, but the strongest effect was observed for BSY hydrolysates, therefore, it presents greater potential as functional ingredient.