Use of absorbents to extend the shelf life of frying oil in food industry

4 1. ABSTRACT The aim of the present study is to evaluate the effectiveness of the use of selective absorbents in the regeneration of sunflower oil used in the frying process in the food industry, in order to extend the shelf life of frying oil, reducing disposal costs by companies, with the consequent reduction of the environmental impact due to the same process of disposal. The analysed frying oil is a sunflower seed oil used for the production of chips by the food company 'Cynara EU S.L.U.' located in the municipality of Mula (Murcia). The study was carried out in the laboratory of the company "Redefine Food Solucion S.L. (Bullas). The samples of oil collected from two different batches have two different cooking times. The oil from the first batch was fried for 10 hours and the oil from the second batch for 40 hours. In the present study only, the samples treated with the different absorbents belonging to the same batch were compared. These samples were mixed individually and then filtered with four different types of adsorbents: bentonite, activated carbon, diatomaceous earth and silicon dioxide. The peroxide level (P- value), P-anisidine value, free fatty acids and colour (CIELAB) were then analyzed. The results showed that all absorbents had a positive effect in reducing oil degradation compounds (P < 0.05). Of these, activated carbon were the most effective, while among the other absorbents there was no clear difference between them. As far as colour is concerned, the activated carbon, due to its characteristic black colour, has proved to be the least effective in clarifying fried oil. In any case, given the limited number of samples and lots analysed, in order to obtain a more significant statistical result, it is advisable to analyse a greater number of lots by taking samples of fried oil at different time intervals for each batch.