The smoke point and melting point of the oil determine the cooking method. The unsaturated fatty acid determines the health of the oil. The aromatic organic matter dissolved in the oil determines the flavor of the oil. The same material, using different processing techniques, containing different ingredients, the applicability is also different. Fried foods are mainly made by cooking oil as a heat transfer medium. Low temperature frying (five or sixty percent oil temperature) is about 130 ° C to 170 ° C. High temperature frying ( seven or eight percent oil temperature) is about 170 ° C. Up to 230 ° C, so the oil used for frying oil is generally higher than 230 ° C. In theory, the higher the smoke point, the more suitable it is to fry, so that during the frying process, it will not generate too much harmful substances.

 

What oils are suitable for frying oil in many oils? The first thing we should consider is that the heating temperature of the oil is generally high when frying food, and the stability and oxidation speed of the oil at high temperatures.

 

1. Considering the oxidation rate----Because of the different fatty acids contained in the oil, the oxidation rate is relatively different, the saturated fat has the highest stability, and the least is easy to oxidize. The higher the degree of saturation of the fried food fat, the less susceptible to oxidation and the less lipid peroxide produced. Therefore, the fat used for frying food is preferably a saturated fatty acid. Palm oil>Animal oil>Olive oil, wild tea oil>Peanut oil>Corn oil>Soybean oil>Rapeseed oil>Su seed oil, flax oil, etc.

 

2. From the perspective of the stability of fat - the relatively high stability of natural oils and fats are butter, cocoa butter cream, etc., its stable value is 2.3-2.4, followed by lard and palm oil, stable The value is 1.5-2.0. The stability of peanut oil in vegetable oil is better, the stability value is 1.2, and other oils and fats are 1.0 or less, such as soybean oil, sunflower oil and the like. Oils with low stability values ​​are not suitable as frying oils.

 

3. The soybean oil and rapeseed oil mentioned above are not suitable for use in deep-frying oil because they contain a certain amount of linolenic acid. Vegetable oils rich in linoleic acid are also not suitable for frying oils. For example, safflower oil and sunflower oil are rich in linoleic acid, which also accelerates oxidation at high temperatures, producing peroxides and trans which are harmful to health. fatty acid.