Production of neuroprotective compounds from barley (<i>Hordeum vulgare</i> L.) germinated under different conditions during the malting process

Abstract The effect of different barley germination conditions on generation of neuroprotective compounds was studied. Malts were obtained by germination at 20 °C for 35 hr (M1), 20 °C for 72 hr (M2), 25 °C for 35 hr (M3), and 25 °C for 72 hr (M4). M4 showed higher phenylalanine ammonia lyase (PAL) activity and total phenolic acid content than the others. Moreover, a direct relationship (r2: 0.9802) between protein hydrolysis degree and malt protease activity was obtained. Regarding neuroprotective properties, all malts inhibited the acetylcholinesterase, tyrosinase, and prolyl oligopeptidase enzymes. However, M4 showed the highest inhibitory activity. This effect was due to the higher proportion of 595 and 392 Da peptides with high hydrophobicity and the higher phenolic acid content in this malt. Thus, the temperature and time of barley germination influenced the enzymatic activity of proteases and PAL, which modified the activity and profile of neuroprotective compounds in malts.