Abstract
In order to prevent the deterioration of edible oils during frying, the preventing effect of protection from exposure to air was examined.
In soy bean oil, 24 pieces of tofu (soy protein curd, 70g weight and 75% moisture) were continuously fried during 7 hours at 110°C and 185°C under the condition that the oil surface was covered and protected from exposure to air by means of metal float. The same oil was repeatedly treated under the above mentioned condition, and after ten times of treatment the chemical and physical properties of the treated oil were compared with the case of frying without the protection.
As a result, it was confirmed that the oxidation and the polymerization of the oil could be almost prevented, but hydrolysis of the oil has been promoted, contradictorily.
