Physicochemical and functional properties of albumin fractions from barley and rye seed protein isolate

Barley and rye are major cereals worldwide and contain proteinaceous α-amylase inhibitors for biological defence against insects. Inhibiting mammalian α-amylase could potentially be a promising functional food characteristic for suppressing postprandial blood glucose levels. This study examined in vitro mammalian α-amylase inhibitory effects and the physicochemical and functional properties of barley and rye albumins, including thermal stability, solubility, emulsifying, and foaming properties, to evaluate their potential applications in various foods. Both barley and rye albumins inhibited mammalian α-amylase and maintained their activity even after heating. High solubility was observed at pH 3.0-6.0, which was maintained after heating at 80 °C for 20 min. Furthermore, barley and rye albumins exhibited high emulsifying and foaming properties at pH 3.0-6.0. These findings suggest that barley and rye albumins are promising materials for suppressing postprandial blood glucose elevation and can be used in various functional foods.