Thermal Induced Physicochemical Changes and Formation of 3-MCPD and Glycidyl Esters in Re-esterified Palm Mesocarp Oil (RPMO) Olein Tuti Ariyani, Budiawan
Department of Chemistry, University of Indonesia
Abstract
Thermal processing of palm oil may induce significant physicochemical changes and lead to the formation of process contaminant that affect oil quality and safety, particularly in restructured oils such as reesterified palm mesocarp oil (RPMO). This study aimed to evaluate the effect of heating duration on physicochemical properties and contaminant formation in RPMO olein. RPMO olein samples were subjected to heating at 200 C for 30, 60, and 90 minutes. The evaluated parameters included free fatty acid (FFA), iodine value (IV), peroxide value (PV), total tocopherol, total carotenoid, as well as 3-monochloropropane-1,2-diol (3-MCPD) and glycidyl esters (GE). The results showed that heating significantly affected the physicochemical characteristics of RPMO olein. FFA increased progressively from 0.37% to 0.93%, indicating enhanced hydrolysis during prolonged heating. IV decreased from 59.59 to 55.74, suggesting a reduction in unsaturation levels. PV increased initially from 0.84 to 2.80 meq/kg at 60 minutes, followed by a decrease to 1.41 meq/kg at 90 minutes, indicating the decomposition of primary oxidation products into secondary oxidation compounds. The content of natural antioxidants decreased markedly with heating duration. Total tocopherol decreased from 1354.61 to 955.40 ppm, while total carotenoid showed a substantial reduction from 348.84 to 47.68 ppm. Furthermore, process contaminants were formed during heating, with 3-MCPD and GE reaching maximum levels at 60 minutes before declining at prolonged heating. These findings demonstrate that prolonged thermal exposure significantly deteriorates oil quality and promotes contaminant formation, highlighting the importance of controlling thermal processing conditions to ensure the safety and stability of RPMO-based products.
