Use of domestic fryer among student families from Madrid university. Acceptation of frozen food fried in extra virgin olive oil, sunflower oil and high oleic acid sunflower oil

The goal of this study was to get information about the use of domestic fryers, type of oil used for frying, kind of food fried in it, and number of frying until rejection of oil. To this aim, a preliminary survey was performed in 50 persons belonging to the Madrid University to know which kind of food and oils they used for frying. None of them used other oils for frying than olive or sunflower oils. Afterwards, another survey was performed between 250 university students, belonging to the Madrid University, in which homes the domestic fryer was used. Information was obtained about kind of oil used, food usually fried, and frying number when the oil used in successive frying was discarded. Most of them employed olive oil and used the same oil 11-20 times, and about the half of them fried only one type of food in the same oil. The most frequent food fried were potatoes, frozen pre-fried potatoes and fish. Fresh foods were preferentially fried in pans while the frozen pre-cooked ones were fried without any priority. Taking into account results of the second survey, 20 frying of frozen foods in extra virgin olive oil, sunflower oil and high oleic acid sunflower oil were performed using domestic fryers. With the aim to analyse the effect of oil used on fried croquette palatability, identifying and punctuation triangular tests were used. The effect of the frying modality (with and without oil reposition) and type of oil used on croquette acceptability were also tested. Croquettes were well accepted obtaining an average score of 6.8 in a scale range from 1 to 10. The organoleptic quality of this food did not change with the number of frying. Nevertheless, the panel was able to identify croquettes fried in sunflower oil from the 6th frying. Croquettes fried in oils with a frequent replenishment obtain a higher organoleptic score than those fried without oil replenishment. Then it should be considered the convenience to perform frying with a frequent replenishment with unused oil.