Application of palm olein in the production of zero-trans Iranian vanaspati through enzymatic interesterification

The utilization of palm olein in the production of zero-trans Iranian vanaspati through enzymatic interesterification was studied. Vanaspati fat was made from ternary blends of palm olein (POL), low-erucic acid rapeseed oil (RSO) and sunflower oil (SFO) through direct interesterification of the blends or by blending interesterified POL with RSO and SFO. The slip melting point (SMP), the solid fat content (SFC) at 10-40 degrees C, the carbon number (CN) triacylglycerol (TAG) composition, the induction period (IP) of oxidation at 120 degrees C (IP120) and the IP of crystallization at 20 degrees C of the final products and non-interesterified blends were evaluated. Results indicated that all the final products had higher SMP, SFC, IP of crystallization and CN 48 TAG (trisaturated TAG), and lower IP120, than their non-interesterified blends. However, SMP, SFC, IP120, IP Of Crystallization and CN 48 TAG were higher for fats prepared by blending interesterified POL with RSO and SFO. A comparison between the SFC at 20-30 degrees C of the final products and those of a commercial low-trans Iranian vanaspati showed that the least saturated fatty acid content necessary to achieve a zero-trans fat suitable for use as Iranian vanaspati was 37.2% for directly interesterified blends and 28.8% for fats prepared by blending interesterified POL with liquid oils.