Deep-frying is very popular, but one of the most complex processes of food preparation, specifically due to the complexity of the products formed. The aim of the present master thesis was to investigate the quality, suitability and stability of different deep-frying oils (coconut, palm, deep-frying oil mix, rapeseed and sunflower oil), the quality and stability of breaded and fried foods (chicken medallions) and to check the applicability and suitability of certain quality parameters (absorption of fat, acid, peroxide and thiobarbituric acid (TBK) numbers, fatty acid composition and acrylamide content) and sensory properties to control the consecutive (three times repeated) deep-frying process with intermittent cooling. Three consecutive deep-frying processes had a significant effect on the hydrolytic and oxidation stability (increase in peroxide and TBK numbers), the sensory properties (darkening of the oil colour, appearance of foreign odours and aromas as well as rancidity in oils and medallions) and the fatty acid composition of oil and fried chicken medallions) and the content of acrylamide in the medallions (from the second frying onward). All oils used were suitable for deep-frying in terms of stability, coconut oil (followed by sunflower, palm, frying and rapeseed oil) was the most suitable, in terms of fatty acid composition the performed deep-frying mix of oils followed by rapeseed and sunflower oil while coconut and palm oils performed the best in terms of acrylamide formation and sensory quality.
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