Recovery of used frying oils with adsorbent combinations: refrying and frequent oil replenishment

Abstract

Treatment of used frying oils with adsorbent combinations may improve the quality of fried foods and extend the frying life of oil. Two selected combinations of four commonly used filter aids: Britesorb (Br), Hubersorb 600 (HB), Frypowder (Fr), and Magnesol (Ma) were used to recover used frying oils by vacuum filtration. The effectiveness of the adsorbent treatments were evaluated by refrying chicken fritters and breasts in the recovered used oil. After 32 h continuous frying, the parameters of treated oil subjected to adsorbent combinations F (3% HB+3% Ma+2% Fr) and B (2% HB+2% Ma+3% Br), were reduced as follows: 61.9 and 59.7%, 38.0 and 11.3%, 25.2 and 19.5%, and 9.4 and 3.5% for free fatty acids (FFA), total polar component (TPC), Foodoil Sensor (FOS) reading, and color differences (ΔE), respectively, compared to the untreated used oil. After daily treatment for 4 days, the filter aid combination F reduced the final values of FFA, TPC, FOS and color differences by 64.2, 19.1, 32.6 and 4.4%, respectively, compared to the untreated control. These adsorbent combinations may be useful in extending the life of frying oils.