Effects of heat, ph, and gamma irradiation treatments on lipase inhibitory activity of sargassum thunbergii ethanol extract

Inhibitory activity of Sagassum thunbergii (ST) against porcine pancreatic lipase was assessed after heat treatment, pH changes, and gamma irradiation. This analysis revealed that the ST ethanol extract exhibited high lipase inhibitory activity (37.37%) at 5 mg/mL. The ST ethanol extract was treated with heat at 60° for 10, 30, and 60 min; 80 and 100° for 10 and 20 min; and 121° for 15 min, pH (2, 4, 6, 8 and 10) and γ-irradiation (3, 7 and 20 kGy). The lipase inhibitory activity of the ST ethanol extract increased in all heat treatments, especially at 121° for 15 min (51.55%) compared with the control. With regard to pH stability, the ST ethanol extract showed no significant changes at pH 4~8, but somewhat decreased inhibitory activity was revealed at pH 2 (26.25%) and 10 (29.93%). On the other hand, the ST ethanol extract was not affected by γ-irradiation treatment conditions used in this study. These results suggest that ST has a potential role as a functional food agent.