Removal of organochlorines from vegetable oils and its benefits in preventing formation of monochloropropanediol diesters

ABSTRACT

This paper reports the first results on depleting certain organochlorines from vegetable oils without the use of any solvent in order to mitigate monochloropropanediol diesters (MCDPE). The concept is based on separating the organochlorines from the bulk oil by using trapping agents (e.g. monoacylglycerols) that can be easily separated from the oil. The process starts by mixing and homogenizing crude vegetable oils with the trapping agent and subsequently separating the trapping agent from the oil bulk via crystallization. The proof-of-concept of the approach is demonstrated on a spiked sunflower model system, solvent extracted crude sunflower oil, industrially produced crude soybean and corn oils. The depletion of organochlorines in the crude oils and its beneficial effect on the MCPDE content in the heat treated samples is measured by LC-MS. The depletion efficacy of the monitored organochlorines was estimated to be in the 60–95 % range. Both the melting point and polarity of the trapping agents affected the depletion efficacy of the organochlorines. Trapping agents with higher melting point and polarity, such as monostearin were more effective in comparison to high melting point but less polar agents such as palm stearin or agents rich in polar but low melting point monolinolein/monoolein. The effect of organochlorine depletion on the subsequent MPCDE levels in heat treated oil was in the range of 60–90 % reduction depending on the type of the studied oil.

KEYWORDS:

• Monochloropropanediol diesters
• mitigation
• monoacylglycerol
• vegetable oil

Acknowledgments

The authors are indebted to Drs. Constantin Bertoli and Dhanavel Gokulrajan for the constructive discussions on current industrial situation and feasibility of MPCD mitigation. The authors would like to thank Dr. Xanthippe Theurillat for the experimental support, Dr. Beat Schneider for providing the distilled MAG samples, Drs. Hoe Kham Foo, Mathieu Dubois and Quentin Basle for providing the palm fruit samples, Dr. Loic Dayon, Dr. Francesca Giuffrida, Cynthia Marmet and Yves-Alexis Hammel for providing access to the Orbitrap MS.

Disclosure statement

No potential conflict of interest was reported by the authors.