Behaviour of sunflower (Helianthus annuus L.) oil and high oleic sunflower oil during the frying of churros

Abstract

The aim of this research was to evaluate the physicochemical quality of two sunflower oils (conventional and high oleic) during the frying of churros, using different analytical methods. Churros are a traditional Spanish foodstuff that is commonly consumed in mass catering establishments and street churros shops. The oil used to prepare them can commonly be subjected to several successive heating cycles. The evolution of parameters, such as peroxide index, iodine index, anisidine index and total polar compounds was determined. After 24 h of frying, the Totox value for high oleic sunflower oil was 87.79, significantly lower than that of sunflower oil (222.36). Furthermore, high oleic sunflower oil reached values above 25 % of polar compounds after 48 h of frying, whereas sunflower oil reached these values after 24 h. This study shows that high oleic sunflower oil showed greater oxidative stability and a lower rate of evolution of deterioration parameters than conventional sunflower oil. The quality of the fried products is determined by the oil and the frying method and is related to the fatty acid composition of the oils, the frying temperature and the frequency with which the oil is renewed.