Effect of germination time on <i>in vitro</i> extractability, and bioavailability of γ-aminobutyric acid, total phenolic compounds, and antioxidant activity of highland barley bread

Abstract This study assessed the impact of the duration of highland barley germination on the in vitro extractability, and bioavailability of γ-aminobutyric acid (GABA), total phenolic compounds (TPC), and antioxidants in highland barley bread. The highland barley was germinated for 24 (GB24), 48 (GB48), and 72 hr (GB72). Following the process of in vitro digestion, the ability to extract GABA increased by 1.13, 1.25, and 1.52 times in GB24, GB48, and GB72, respectively, compared with before germination. Furthermore, the process of germination resulted in an increase in the amount of GABA that was available for absorption in GB24, GB48, and GB72 bread, with percentages of 81.67%, 88.20%, and 89.49% correspondingly, compared with 72.59% in NB samples. In the case of GB24, GB48, and GB72 bread, the process of germination raised the extractability of TPC by 1.43, 1.50, and 1.57 times, respectively. Additionally, it resulted in an increase in bioavailability by 79.92%, 83.59%, and 81.63% correspondingly. In the same manner, germination enhanced the extractability and bioavailability of antioxidants in all types of germinated highland barley bread. Thus, germination could serve as a recommended pretreatment for highland barley before its inclusion in meals in order to augment the presence of these advantageous constituents.