The occurrence of 3-monochloropropane-1,2-diol esters and glycidyl esters in vegetable oils during frying

Abstract

3-monochloropropane-1,2-diol esters (3-MCPDE) and glycidyl esters (GE) are processed-developed contaminants presence in vegetable oils after undergo refining process under excessive heat. Refined oils are extensively used in various frying applications, nevertheless, the reservation against their quality and safety aspects are of major concern to consumers and food industry. Realizing the importance to address these issues, this article deliberates an overview of published studies on the manifestation of 3-MCPDE and GE when vegetable oils undergo for frying process. With the modest number of published frying research associated to 3-MCPDE and GE, we confined our review from the perspectives of frying conditions, product properties, antioxidants and additives, pre-frying treatments and frying oil management. Simplicity of the frying process is often denied by the complexity of reactions occurred between oil and food which led to the development of unwanted contaminants. The behavior of 3-MCPDE and GE is closely related to physico-chemical characteristics of oils during frying. As such, relationships between 3-MCPDE and/or GE with frying quality indices – i.e. acidity in term of free fatty acid or acid value); secondary oxidation in term of p-anisidine value, total polar compounds and its fractions, and refractive index – were also discussed when oils were subjected under intermittent and continuous frying conditions.

Keywords:

• 3-monochloropropane-1,2-diol esters
• glycidyl esters
• contaminants
• frying
• quality indices

Acknowledgements

Our sincere appreciations are also extended to the Director of Product Development and Advisory Services Division members of the Analytical Quality Development Unit.

Additional information

Funding

The authors are grateful to the Director General of Malaysian Palm Oil Board for granting us the permission to publish this review article.