Effects on Edibility of Reused Frying Oils in the Catering Industry

Abstract

In this study, significant fatty acids, trans fatty acids, peroxide value, and free fatty acids of 25 samples collected from general restaurants, fast-food restaurants, and catering companies in Afyonkarahisar province and neighboring areas were analyzed. Fresh sunflower oil was used as the reference oil An amount of 50 g of potato pieces was fried at 180 degrees C for 3 min in every frying interval for a total of 15 times of frying in the same oil Oleic, linoleic, linolenic, trans fatty acids, peroxide value, and free fatty acids of this fresh oil were measured after every frying process and compared to oils collected from different sources. The purpose of this study was to determine the utilization level of frying oils for the restaurant sector to reveal their effect on human nutrition and health as an investigation on recycling oils for the national economy. As a result of the study, free fatty acid levels reached a maximum codex level of 0.6 g/100 g oil at the eighth time frying interval and this level in it reached a 0.3 g/100 g oil codex level at the third time frying. This point was assumed as the start of the rancidity level A sixth time frying interval gave 10 meq/kg of peroxide value and this point was accepted as the maximum codex level of the Turkish Food Codex, but a hydroperoxide occurence level of 5 meq/kg seemed to be the result of these findings at the third frying interval. It could be said that three times of frying could be done with the same oil, but these oils must be filtered after each use and stored in cold conditions. The results showed that more than half of the companies used these frying oils at least more than three times.