Optimization of palm oil deodorization process conditions by RSM

Abstract

Deodorization is a very critical process in edible oil refining since it is the last step before obtaining refined oil. While it was a simple process for the industry to remove undesirable odor compounds in the beginning, it has become more and more crucial. Nowadays, a proper deodorization process is also used to remove free fatty acids (FFA), color and some contaminants such as PAH, 3-MCPD, pesticides. The principle behind deodorization is passing a stripping agent, usually steam, through a hot oil for a specified time under vacuum conditions. These parameters should be optimized thoroughly to obtain an oil with improved freshness and sensory properties along with less contaminant.In this study, optimum deodorization conditions of bleached palm oil, which may contain or form higher amounts of FFA and 3-MCPD/GE intrinsically compared to other vegetable oils, were determined by keeping steam amount constant. Response Surface Methodology (RSM) was applied using three variables such as deodorization temperature, time and pressure. Deodorization trials were carried out according to the determined RSM experimental design at the Multipurpose Pilot Plant in Besler R&D Center. The analyses of oxidative stability (Rancimat), moisture, Anisidine value (AV), free fatty acids (FFA), Lovibond colour (red), 3-MCPD, Glycidyl esters (GE), and fatty acid compositions were perfomed according to the official methods. Trans isomerization was observed through cis C18:2/C16:0 ratio.Significant factors were determined by performed ANOVA on each model. Consequently, with these significant factors, optimum deodorization condition of palm oil was obtained with 0.87 desirability. The optimization was also verified with several validation runs at the optimum point.