Relationship between the composition of fats and oils and their oxidative stability at different temperatures, determined using the Oxipres apparatus

摘要

The oxidative stability of 12 edible fats and oils was determined at three different temperatures (80, 100, and 120 degrees C) using the Oxipres apparatus, and compared with their characteristics (peroxide value, fatty acid composition, antioxidant capacity determined by the DPPH method and tocopherol content). Using a simple correlation analysis, oleic acid content was found to correlate most strongly with the oxidative stability of the analysed fats and oils (p<0.01). Highly reliable models (p<0.00001), defined the induction period as a function of the oleic/linoleic acid ratio, antioxidant capacity and peroxide value, were obtained by multivariate linear regression analysis at each of the three temperatures. In additional experiment, the effect of temperature on the induction period of sunflower oil, pork lard and extra virgin olive oil was studied in detail within the temperature range of 80-130 degrees C. It was found that the logarithm of the induction period decreased linearly with increasing temperature (p<0.01). However, the induction period of the different fats and oils decreased with temperature to a varying degree, i.e., the ratio between the induction periods of these fats and oils was affected by the temperature. Practical applications: Analyses to determine the oxidative stability of fats and oils are frequently required by food manufacturers, who use this information for the quality control of raw materials and, in particular, the selection of suitable fats or oils for food production. However, only a relatively small number of analytical laboratories are able to determine and interpret results obtained for the oxidative stability of fats and oils. On the other hand, determination of the composition of edible fats and oils (fatty acid composition, tocopherol content and other parameters) are routinely performed analyses. The ability to predict the oxidative stability of fats and oils from these commonly determined parameters can assist the selection and quality control of suitable raw materials for food manufacturers. The oxidative stability of selected edible fats and oils is determined at different temperatures using the Oxipres apparatus, and compare with their characteristics. Highly reliable models defined the induction period as a function of the oleic/linoleic acid ratio, antioxidant capacity and peroxide value, are obtained by multivariate linear regression analysis at each of the three temperatures.