Quality and Sensory Evaluation of Used Frying Oil from Restaurants
Nada Vahčić* and Mirjana Hruškar
Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, HR-10000 Zagreb, Croatia
Article history:
Received January 15, 1999
Accepted February 15, 1999
Key words:
used frying oil, sensory evaluation
Summary:
Deep fat frying is one of the most commonly used procedures for the preparation of food. The necessity of using a good quality frying medium becomes obvious when considering that some of the fat is absorbed by the food fried in it. In 46 samples of used frying oil from restaurants in Zagreb or fast food outlets, iodine value, peroxide value, refractive index, free fatty acid (as oleic fraction), p-anisidine, total polar components, oxidized fatty acids and sensory properties were determined. The aim of this study was twofold: first, to show the quality of used frying oil obtained from restaurants in Zagreb and fast food services; second, to correlate the results of some investigated physico-chemical parameters with sensory evaluation. Linear relationships among them were determined, coefficients of correlation were generally high (r = 0.850 – 0.942) and, consequently, very accurately predicting equations were obtained by regression analysis. It may be concluded that sensory evaluation is a fast and simple method and can be used as a reliable indicator in the frying oil quality estimation.
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