Abstract
Effects of commercial soybean lecithin (SPC) on the various properties of oil used for pan-frying were tested. SPC was added to a corn oil in the range of 0.25-3.0%. These oils were tested using an apparatus designed as a model of pan-frying. SPC markedly influenced the changes in various properties of oil during pan-frying. The following results were obtained.
1. Waving motion of oil surface: When corn oil was heated over 180°C in a state of thin film, unevenness of the oil surface occurred. That is, Concavo-Convex was formed on the surface of the oil. This phenomenon was described as “waving motion of oil surface”, and was effectivelly prevented by the addition of SPC.
2. Deterioration of oil: When SPC was added to corn oil in the range of 0.5-1.0%, thermal oxidative deterioration measured by peroxide or total carbonyl values was effectively prevented. However, the presence of SPC over 1% caused a great increase of browning in heated oil.
3. Heat adhesion of protein food: When corn oil was heated over 160°C at the state of thin film, heat adhesion of chicken meat to the pan surface occurred. But this phenomenon was effectively prevented by the addition of SPC.
4. Foaming tendency: When SPC was added to corn oil over 1%, a remarkable foaming was observed during the cooking of chicken meat.