Study On The Effect Of Frying On Corn Oil Quality And Functional Components

This paper focusing on proceeding of several frying experiment by continuous or interval frying patern in 170℃ and 190℃,in which corn oil was used as frying medium, and dough sticks, chicken wings, old bean curd, weter bean curd, bean curd skin, french fries, peanut, pork slice were used as frying ingredient. In the process of frying made corresponding oil, and frying temperature,frying time and frying ingredients of acid value, carbonyl value, polar components, the change of phytosterol and vitamin E was analysised.With prolonged frying time, in 170℃ and 190℃, the acid value of corn oil was increased gradually. Without frying, the acid value was 0.33mg/g, and in 170℃ and 190℃the acid value were 2.16mg/g and 2.40mg/g after frying for 32 h respectively.And, the acid value in 170℃ is lower than 190℃ at the same time. With prolonged frying time, the content of vitamin E was continue to drop. By analysis of variance, the temperature has significant effects on the Vitamin E content of corn oil.The content of δ-tocotrienols remain unchanged, the rest of Tocopherol monomer content and decreased with the prolonged of frying time. Corn oil sterol content was 893.2 mg/100 g.In the different frying intermittent(continuously). Corn oil fried fritters 8h, oil physical and chemical properties and quality index occurred different degrees of deterioration. Continuous frying conditions of acid value at the same time, polar component and carbonyl value than the batch frying conditions to be low. After t test, there was significant difference between intermittent and continuous frying of carbonyl fried corn oil value(P<0.05).Corn oil batch frying food after 8h, acid value, polar group and carbonyl value were increased with the frying time is rising trend. By variance analysis, in the levelα=0.01, the food has a significant effect on the vitamin E content of corn oil. The loss of the tocopherol monomer ingredients of corn oil after frying fourth in order Chicken wings> Deep-Fried Dough Sticks >French fries > tofu. Frying different ingredients in corn oil sterols content decreased with the frying time, the bean curd fell the most, French fries decline rate was lowest.In 190 ℃, corn oil batch frying at different moisture ingredients 8h, the change trend of the biggest is containing the largest amount of the tender bean curd, the minimum is control group, we can get the acid value of corn oil, carbonyl value and polar components with frying ingredients of the moisture content increased. Fried in different moisture ingredients, the content of vitamin E in corn oil decreased followed by the control group > Laodou Fu > water tofu > bean curd skin.In 190 ℃, the different corn oil batch frying fat composition ingredients 8h and change trend of the largest is the wings, the minimum is peanuts, corn oil acid value, carbonyl value and polar fractions and fried food fat composition is significantly correlated(P < 0.05). Frying different fat ingredients after loss of vitamin E in corn oil Chicken wings > Little Su meat > control group > peanut. The composition of fatty tocopherol monomer and the ingredients in the fourth frying frying ingredients in corn oil. Fried peanut corn oil sterols content changes is decreased first and then increased, while the control changes is decreased first and then increased and then decreased. The loss of these four ingredients after frying sterol in corn oil rate followed by the size of Little Su meat > Chicken wings > peanut > control group.