Comparison of pretreatment methods for the simultaneous determination of synthetic antioxidants in edible oil

Abstract

Synthetic antioxidants such as propyl gallate (PG), octyl gallate (OG), dodecyl gallate (DG), 2,4,5‐trihydroxybutyrophenone (THBP), tert‐butylhydroquinone (TBHQ), butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) have been used to prevent oxidative degradation in edible oils and fats. These antioxiants in USA, EU and other countries can be added singly or together up to the final concentration of 200 mg/kg. Although the PG, TBHQ, BHA and BHT are an antioxidant authorized as a food additive in Korea, the OG, DG and THBP are unauthorized. In our previous study, we developed a simultaneous method to identify synthetic antioxidants using high‐performance liquid chromatography with UV detector (HPLC‐UV). However, pretreatment with high recoveries are not established yet. Therefore pretreatment method is needed to detect synthetic antioxidant in edible oil. The present study was conducted to compare the different pretreatment methods including Korean Food Standards Codex, AOAC, AOCS and article. The results showed that Korean Food Standards Codex official method is more suitable for the simultaneous determination of synthetic antioxidants compared to other methods. Recoveries of synthetic antioxidants were in the range from 89.6 to 98.8% with RSDs between 2.8 to 4.2%. The Korean Food Standards Codex official method has been successfully applied to edible oil.