Abstract
In previous paper, it was reported that the deteriolation of oil was severer in the case of frying the wet cotton seats, employed as the model system, than this after the frying foods, and the content of iron in oil was also higher in the case of former than the latter.
To clarify this phenomena, protein rich foods and starchy food were fried with oil containing ionic iron, and the deteriolation of oil was compared.
1) When protein rich food, such as soy bean curd or halibut was fried with this oil, the amount of iron in oil was less compared with the case of starchy food, like as potatoes.
From this, it was assumed that the iron ion in oil could compose some kinds of complex with protein and the complex would precipitate out from oil phase, while this complex would not be formed with starch or starch gel.
2) When foods were fried with iron containing oil, the color, acid value and TBA value were improved gradually during this processing and these characteristics became similar to those of fresh oil.
3) In the range of the usual cooking conditions, the amount of iron dissolved into oil from iron pan would scarcely affect the taste of fried foods.
