Abstract
In the previous paper, the author reported that the fish oil, polymerized by heating ina Co2, stream or in air at about 250°C for 10 hours, shows toxicity to rats, that this toxicityis due to the cyclic ethyl ester separated from this oil by the urea-adduct forming method, while the straight chain ethyl ester has a sufficient nutritive value and shows no toxicityat all.
In this paper, the experiment on edible rape-seed oil will be reported. This oil, whenpolymerized by heating at 250°C for 50 hours, shows toxicity to rats, and in this case alsothe cyclic ethyl ester, separated by the same method as in the case of the fish oil, showsnoticable toxicity to rats, though somewhat lower than that separated from fish oil.
Toomuch heating, therefore, should be avoided even in the case of edible oil.
