Generation of phenolic-rich extracts from brewers' spent grain and characterisation of their in vitro and in vivo activities

Abstract Brewers' spent grain (BSG) is a co-product of the brewing industry, which is rich in phenolic acids. This study compared the in vitro bioactive properties of aqueous, aqueous pH-shift and enzyme-aided phenolic extracts from pale (unroasted) wet BSG. Overall, the pH-shift extracts showed higher oxygen radical absorbance capacity (ORAC), trolox equivalent antioxidant capacity (TEAC) and ferric-reducing antioxidant power (FRAP) values compared with the enzyme-aided extracts. A selected enzyme-aided extract showed highest in vitro ACE inhibitory activity (ACE IC50: 0.133 ± 0.032 mg mL−1) and mediated significant (p