Impact of roasting on the chemical composition and oxidative stability of perilla oil.

The impact of roasting was observed with regard to certain changes in the chemical components and oxidative stability of oil expelled from the roasted perilla seeds. The roasting times were established differently at each roasting temperature of 180, 200, and 220 °C. Trans fatty acids in perilla oil were detected, and the level detected increased as the roasting time increased. Moreover, the roasting of perilla seed led to an increase of 4 tocopherols, α-, β-, γ-, and δ-tocopherol, as well as phosphorus in the oil. The oxidative stability of the oils obtained after roasting increased during 60 d of storage at 60 °C. The rate of decrease of tocopherol in the oil from unroasted perilla seed was faster than that of the tocopherol in the oils from roasted perilla seeds during storage.