Effects of Food Types, Frying Frequency, and Frying Temperature on 3-Monochloropropane-1,2-diol Esters and Glycidyl Esters Content in Palm Oil during Frying.

Jinglin Zhang,Wendi Zhang,Yuanzheng Zhang,Baoguo Sun,Mingquan Huang

doi:10.3390/foods10102266

Abstract

3-Monochloropropanediol esters (3-MCPDE) and glycidyl esters (GE) have high toxicity and have drawn global attention because of their widespread occurrence in refined oils and oil-based foods. In this study, the effects of food type (potato chips and chicken breasts), frying frequency, and frying temperature on the formation of 3-MCPDE and GE in palm oil (PO) were investigated. The results showed that 3-MCPDE was formed easier in chicken breasts than potato chips. The GE content decreased in PO after it was used for frying potato chips and chicken breasts with or without NaCl. Frying frequency was an influencing factor in the formation of 3-MCPDE and the decrease in GE in PO. Frying temperature was positively correlated with GE degradation, while it had a bidirectional effect on the formation of 3-MCPDE. The formation kinetic equations indicated that 3-MCPDE and GE followed zero-order reactions in PO. The estimated activation energy (Ea) of 1,2-bis-palmitoyl-3-chloropropanediol (Pa-Pa, 41.05 kJ/mol) was lower than those of the other three types of 3-MCPDE; this is the first theoretical explanation for why PO contains more 3-MCPD than other edible oils. Among GEs, glycidyl oleate (Li-GE) was degraded more readily than other GEs.

Highlights

Elucidating the formation of 3-monochloro-1,2-propanediol esters (3-MCPDE) and glycidyl esters (GE) during heat processing of frying foods is vital for reducing risks to human health
A large part of the MCPD in foods is esterified with fatty acids, while a very small part is free. 3-MCPDE and GE have been reported in biscuits, infant formulas, and various types of vegetable oils, especially refined palm oil
The advantage of the direct analysis method is simplicity, and provides information about the fatty acid composition of 3-MCPDE and GE; a large number of standards are used during the analysis [23]

Summary

Introduction

Elucidating the formation of 3-monochloro-1,2-propanediol esters (3-MCPDE) and glycidyl esters (GE) during heat processing of frying foods is vital for reducing risks to human health. Researchers have investigated the content of 3-MCPDE and GE in oils during the refining process and during food processing. In addition to being generated in refined oil, 3-MCPDE and GE in oil could migrate into foods during food processing. Recent studies have found that fried foods contain higher concentrations of 3-MCPDE and GE than other types of foods. These contaminants migrate to fried foods from frying oil rather than being formed in the foods themselves during frying [9]. It is worthwhile to study the changes in the content of 3-MCPDE and GE in oil during frying

Methods

Results

Conclusion