Comparative assessment of thermo-oxidative stability of palm oil designer lipid and palm oil blends as frying medium

Abstract

The current study focuses on comparing the physico-chemical changes during frying of palm oil designer lipid (PODL) and two different blends of palm oil with medium chain triglycerides (MCT) over 48 frying cycles. The PV of PODL, F1 (blend of palm oil with MCT in 50:50 proportion) and F2 (blend of palm oil with MCT in 70:30 proportion) increased from 1.29 ± 0.02, 1.34 ± 0.00, 1.38 ± 0.01 to 1.36 ± 0.02, 1.83 ± 0.02, 1.94 ± 0.02 meq O2 / kg respectively after 48 frying cycles. Similarly, p-AV and Totox values were 39.5 ± 0.01 and 42.22 ± 0.01, 52.8 ± 0.02 and 56.46 ± 0.03, 61.7 ± 0.01 and 65.58 ± 0.02 for PODL, F1 and F2 respectively after 48 frying cycles confirming that PODL showed higher thermo-oxidative stability in comparison with palm oil blends. The viscosity of all the frying medium increased and also there was a change in color of frying oil upon successive frying indicating accumulation of oxidative byproducts in the frying oil. Heat transfer coefficient was also elucidated to decrease with an increase in the frying cycle for all the blends and PODL. Overall, it was clearly demonstrated that the physicochemical properties and heat transfer quality of PODL was less affected as compared with palm oil blends demonstrating excellent potential of the PODL/interesterified fat as an alternative frying medium.

Keywords

• Frying
• Palm oil
• Medium chain triglyceride
• Designer lipids
• French fries
• Structured lipids