Question

    Which of the following factors not promote oxidation in

    Oil & Fat
    A Heat Correct Answer Incorrect Answer
    B Light & Availability of oxygen Correct Answer Incorrect Answer
    C Degree of unsaturation Correct Answer Incorrect Answer
    D None of the above Correct Answer Incorrect Answer

    Solution

    Promoters of oxidation Recognition of catalysts, factors and conditions that promote or contribute to oxidation of lipids is essential if these conditions are to be controlled. Some of the most important factors are: 1. Heat. Oxidation is typical of most chemical reactions. A 10 ° C increase in temperature doubles the reaction rate. 2. Light . Ultraviolet light is a powerful initiator and catalyst of oxidation. 3. Heavy metals . Dissolved metals such as iron and copper are also effective catalysts for oxidation at the ppm level. 4. Alkaline conditions . Basic conditions and alkaline metal ions promote free radical oxidation. 5. Degree of unsaturation . Number and position of double bonds in fat molecules can be directly related to susceptibility to oxidation; for example, linolenic acid is more easily oxidised than oleic acid. 6. Pigments . Residual pigments found in vegetable oils promote oxidation. Chlorophyll, for example, can promote oxidation of various oils by producing singlet oxygen. 7. Availability of oxygen . Oxygen is required for oxidation.

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