The Kinetic Study Of Structures, Fatty Acid And Volatile Compounds In Palm Oil Deep-fat Frying Process

Deep-fat fried foods have been very popular because of its unique flavor. Since the processing temperature is high, the chemical reactions among food materials, frying oil and oxygen in the air contribute to a very complex process, which needs to be studied on its kinetic variance. Meanwhile fried foods will be dehydrated suction at high temperatures, so that the processing of the product along with some oil into the body and affect health. This experiment explored the dynamics of changes of different foods at different temperatures and frying the processing time of texture, and in-depth analysis of the palm oil fatty acids and volatile components changes in the frying chicken breast. Experimental results are as follows:The texture of protein-rich foods (tofu), high-carbohydrate foods (potato) and meat (chicken breast) at 150℃,170℃ and 190℃ under different conditions of continuous frying has been analysised by the texture analysis method (Texture profile analysis) analysis. The results showed that the hardness of tofu may not be significantly enhanced along with the increase of frying time increases. But there is a peak at a temperature of 155℃-185℃, time 200s-220s, the highest point of the peak is about other 5 times the hardness of tofu, which indicates that tofu fried under that conditions have been serious dehydrated. The hardness of potatos generally decreased along with frying process. The reason for that is the fried potato has lost moisture, which appearance absorb grease becomes soft. Since the chicken breast composition is more complex than tofu or potato, there was not trend for the hardness of chicken breast under deep-fat frying process. Practically speaking, the quality control of chicken breast will depend on its Tc, which can ensure the chicken breast is cooked well.The qualitative and quantitative analysis of fatty acid compounds in palm oil fried chicken breast has been studied by external standard method using SPME-GC-MS. From the beginning of deep-fat frying to 36h, the general fatty acid did not significantly change. The reason for that may because the palm oil itself contains antioxidants such as tocopherol, which could make it more resistant to deep-fat frying process. On the other hand may be because the experiment design is not long enough, which did not empact on the oxidation and decomposition of fatty acids in palm oil.The qualitative and quantitative analysis of propionate ester of the same bench of palm oil fried which chicken breast has been analysised by the internal standard method using SPME-GC-MS. The aldehydes, ketones, alkanes and other volatile substances have been identified. Aldehydes are the most commone volatile compounds, which has a decisive influence on the flavor of fried chicken breast. In aldehydes, trans-2,4-decadienal and other harmful aldehydes also appears in the palm oil, which could be considered as important factors in the quality control of the frying oil. The control of frying oil quality is beneficial for consumers by limiting the fried food intake of harmful substances in the oil.