Abstract
The author fried foods in soybean oil added with antioxidants (Butyl hydroxyanisole, Hydroquinone) at 17°C for five minutes observing how many times the oil could be used, and measured the quantity of oil absorbed in fried foods and the smoking point. According to the experiment, the author guessd that the antioxidants was decomposed by heating, since in heated oil its action was gradually lowered.
In order to prove the decomposition by heating, the author separated antioxidants contained in oil (Butyl hydroxyanisole, Butyl hydroxytoluene, Hydroquinone, Propyl gallate, Iso amyl gallate) with silicagel column and extracted them by using ethyl acetate, then paperchromatographed the extract and judged the degree of decomposition of antioxidants from the colorification.
The following results were obtained; BHA was decomposed in 60 minutes, BHT in 120 minutes, Hydroquinone in 60 minutes, PG in 30 minutes and Isoamyl gallate in 60 minutes.
