Comparison of the influence of frying and idling on color indicators of French fries and sunflower oil used for frying

Color is the indicator used in food industry for fast quality control of oil for frying. The research objective was studying the influence of degradation of sunflower oil when frying and idling on its color characteristics and the quality both of the oil used for frying and final product. It was shown that if L, a *, b * indicators of color of final product practically did not depend on, whether continuous frying of the product was conducted on the oil or if there was single heating, L, a *, b * indicators of color of the oil product used for frying in these options of the experiment by the end of the test differed considerably. Thus the integrated indicator of color ΔE for single heating of oil was lower in the beginning, and after 30 fryings (the 10th day of the experiment) became higher than this indicator for the oil used for frying of the product. Thus by the 10th day of the experiment in the oil exposed to single heating also the emer-gence of specific smell and the smack which were missing at this stage of the experiment in the oil product used for frying was noted. Thus, except the changes in the composition of oil taking place when frying owing to thermooxidation and pyrol-ysis at single heating oil is exposed also to other physical and chemical influences having the impact on its characteristics which start prevailing after using oil during 20 fryings. The conclusion is drawn that for the comparison of quality of oil during frying expediently instead of value of white color of oil L to use an integrated indicator ΔE, including all color charac-teristics.