2020 年 32 巻 4 号 p. 83-88
The activities of three kinds of lipases, namely, Candida cylindracea (AYS Amano), Pseudomonas fluorescens (AK Amano), and Burkholderia cepacia LP-7 (PS Amano SD) were investigated in enzymatic hydrolysis of canola oil. Among the lipases, AYS Amano had the highest activity in the hydrolysis of canola oil, where 60% of triglyceride (TG) was hydrolyzed in 8 h at 40 °C. The TG was degraded rapidly in 2 h, where 50% of TG was hydrolyzed to diglyceride (DG), monoglyceride (MG), and fatty acid (FA). However, the rate of hydrolysis decreased after 2 h due to a reverse reaction. Lipase inactivation by gamma ray irradiation was also examined in absorbance dose range of 0.2-1.0 kGy. The results demonstrated that the inactivation of lipase in the aqueous phase was higher than that of powder in the solid state. Moreover, ionizing radiation treatment was effective for the inactivation of lipase in oil seeds, and this inactivation method can be used to stabilize oil for long-term storage.