Changes in phenolics, γ-aminobutyric acid content and antioxidant,antihypertensive and hypoglycaemic properties during ale white sorghum (Sorghum bicolor (L.) Moench) brewing process

Effects of white sorghum brewing process on free amino-acids, γ-aminobutyric acid (GABA), phenolics and bioactivity, including antioxidant (by ABTS⁺ and reducing power, RP, methods), antihypertensive (angiotensin converting enzyme-I, ACE-I inhibition assay), and hypoglycaemic activity (α-glucosidase inhibition assay) were evaluated. From the wort to the beer, free amino acids decreased, but GABA and phenolics increased significantly, positively modifying the bioactive potential. ABTS and α-glucosidase inhibition activity correlated positively with at least one of the phenolic acids evaluated. Ale white sorghum beer presented high content of GABA (7.8 mg L^?1), phenolics (40.7 mg total phenolic acids L^?1), antioxidant activity (9.14 mmol Trolox equivalent L^?1, and 48.8 mmol ascorbic acid equivalent L^?1, for ABTS⁺ and RP, respectively), and exhibit ACE-I inhibition (1.0 μg captopril equivalent L^?1) and α-glucosidase inhibition (34.5 mg acarbose equivalent L^?1) activities. The level of bioactive compounds and its low ethanol content (2.3%), make beer obtained from malted white sorghum a potential functional beverage.