A study of the ability of bioactive extracts from brewers' spent grain to enhance the antioxidant and immunomodulatory potential of food formulations following in vitro digestion

Abstract

Bioactivity of a snack-bar, chocolate-drink and yogurt fortified with brewers' spent grain (BSG) phenolic extracts (P2 or B2) or protein hydrolysates (barley protein hydrolysate (BPH), BPH < 3 kDa, BPH < 5 kDa, BPH > 5 kDa) was measured following gastrointestinal in vitro digestion. Concentrations of 0.5 and 0.1% (v/v) digestates were chosen for addition to Caco-2 and Jurkat T cells, respectively. Yogurt and B2 digestate protected against H₂O₂-induced DNA damage in Caco-2 cells (p < 0.05), by the comet assay. Snack-bar digestates possessed significant (p < 0.05) immunomodulatory effects, measured by ELISA in concanavalin-A stimulated Jurkat T cells. Addition of BPH enhanced (p < 0.05) the IFN-γ reducing capacity of the snack-bar while addition of BPH < 3 and < 5 kDa reduced IL-2 production to a greater extent than unfortified yogurt (p < 0.05). Selected BSG components can enhance the antioxidant and anti-inflammatory potential of foods.

• Bioactive
• brewers' spent grain
• fortified
• functional
• phenolic extract
• protein hydrolysate

Declaration of interest

Funding for this research was provided under the National Development Plan, through the Food Institutional Research Measure, administered by the Department of Agriculture, Food and the Marine, Ireland. The authors declare no conflict of interest.