Abstract
The objects of this study was to investigate and to discuss on the fundamental factors for pan-frying from the viewpoint of cooking. Several foods such as cabbage, bean sprout, egg, rice, meat and fish were pan-fried with different amounts of vegetable oil, lard, butter and margaline. The result showed that the proper amount of oil to cook the foods was 5-10% of the foods and that was same with any kind of oil (Table-2). Temperatures during cooking were measured from 3 points, namely the bottom of frying-pan, the surface of food and the center of foods for each food (Fig. -1, 2). The weight loss of foods during pan-frying was about 10% in general, but about 20% for watery ones such as cabbage and bean-sprout, The weight loss was also affected by heating power and by the amount of contents (Table-3, 4).
The amount of oil and water left in the bottom of pan was also affected by heating power, when watery foods were pan-fried. It seemed desirable for watery foods to cook with strong heat and for a short time.
When oils are used for pan-frying, the oils are heated in a form of very thin film though for a short time. In order to determine the extent of deterioration of oils during pan-frying, acid values, iodine values and TBA values of soybean oils heated in thin film at 100°C and 180°C, and of oils used for pan-frying of rice and bean-sprout were measured. The fatty acid contents of these oils were also determined by gas chromatography. It was found that oils used for pan-frying deteriorated considerably, though in a short time (Table-5, 6).
