Determination of epoxidized soybean oil in bottled foods

A determination method for epoxidized soybean oil (ESBO) in bottled foods was developed and used to survey bottled foods on the Japanese market. The amount of sample required was decreased to 20 g and the standard addition method was adopted for the quantification, because lipid in foods interrupted the hydrolysis of ESBO. The recoveries were 87.1 and 98.9% and the determination limit was 5.0 microg/g for a 20 g sample, be cause lipid in foods interupted the hydrolysis of ESBO. The recoveries using the internal standard method varied widely, because hydrolysis of the internal standard, cis-11,14-eicosadienoic acid ethyl ester, was affected more than that of ESBO by coexisting lipid in the sample. ESBO was not detected in any of the bottled baby food samples examined (14 samples), though it had been frequently detected in previous European surveys. This difference may be related to the low fat content and low fluidity of the bottled baby foods retailed in Japan. On the other hand, ESBO was detected at levels of 25.7-494.0 microg/g in liver paste, pasta sauce, Sungan in spicy oil, and spicy oil. These foods had higher fat content and higher fluidity. However, ESBO intake from these foods appears unlikely to exceed the TDI in the EU (1 mg/kg bw/day).