Organic, conventional and sustainable palm oil (RSPO): Formation of 2- and 3-MCPD esters and glycidyl esters and influence of aqueous washing on their reduction.

Palm oil is a type of vegetable oil which presents a variety of applications including food, energy, and international trading. However, one of the major concerns associated with palm oil uses as a food ingredient is the significant amount of processing contaminants, such as monochloropropanediol esters (MCPDE) and glycidyl esters (GE) which are formed during the refining process. These contaminants may pose a health risk to consumers due to their carcinogenicity. Thus, mitigation strategies have been studied to reduce these substances in palm oil. In this study, we investigated the effect of the application of an aqueous washing step, as a mitigation strategy, prior to deodorization in three different palm oil cultivation systems: organic, conventional and certified palm oil by the Roundtable on Sustainable Palm Oil (RSPO). In addition, we evaluated the quality parameters after the application of the washing step. For the organic, conventional and RSPO palm oil samples, the aqueous washing step reduced approximately 41%, 34% and 36% of the 3-MCPDE, respectively. The levels of 2-MCPDE for the organic, conventional and RSPO palm oil presented a reduction of 55%, 41% and 32%, respectively. The GE levels are considerably low for all the deodorized palm oils, and presented no statistically significant difference (p > 0.05). Besides, the quality parameters such as free fatty acids, color, and OSI met the recommended limits. Therefore, the aqueous washing could be used as a supplementary strategy to reduce these contaminants from palm oil.

Washing bleached palm oil to reduce monochloropropanediols and glycidyl esters.

The formation of toxic compounds, potentially carcinogenic, during food processing has been considered an important food safety issue. Among them, particular attention has been given to 3-monochloropropane-1,2-diol esters (3-MCPDE), 2-monochloropropane-1,3-diol esters (2-MCPDE) and glycidyl esters (GE), which can be formed during vegetable oil refining, especially palm oil. These substances may pose a health risk to humans due to their toxicity and carcinogenicity. The aim of this study was to investigate the effect of washing bleached palm oil (BPO) with different solvents, and evaluate the reduction of 3-MCPDE, 2-MCPDE and GE as well as assess the quality parameters of the final product. For this purpose, we used two types of washing with different solvents. A single washing was carried out in one step and a double washing in two steps using a solvent gradient. Single washing had a limited reduction in the levels of 3-MCPDE and 2-MCPDE and resulted in an increased level of GE, whereas double washing slightly reduced 3-MCPDE and 2-MCPDE and resulted in a significant reduction of GE levels. The reduction achieved in this study was up to 17.1% for 3-MCPDE, 56.4% for 2-MCPDE and 76.9% for GE levels. The reduction of 3-MCPDE and 2-MCPDE might be due to the removal of part of the ethanol-soluble chlorinated precursors from the oil which suggests that highly lipophilic forms of these substances are present in BPO. The substantial reduction on GE levels might be associated with the removal of the precursors present in the oil such as diacylglycerols. Thus, the washing treatment could be used as a supplementary strategy to reduce processing contaminants from palm oil, especially GEs.