Impact of Different Drying Techniques On the Yield, Oxidative Stability, And Thermal Properties of Palmitic Acid Extracted from Mango (Mangifera indica) Seed Kernel

Abstract

Objective: Evaluate the impact of the different drying techniques such as hot air oven (HAD) (60°C), electrohydrodynamic drying (EHD) (needle-to-plate setup, 15 kV), freeze-drying (FD) (-50°C, 48 h), and microwave drying (MD) (700 W) to assess energy consumption, yield and stability of the palmitic acid. Methodology:The lipids were extracted using Soxhlet with n-hexane and palmitic acid content was isolated as fatty acid methyl esters. The extracted acid was characterized using FTIR, XRD, and FE-SEM. The oxidative stability was assessed using peroxide value (PV) and thermal properties were characterised by differential scanning calorimetry (DSC). Results and conclusions: FD yielded the highest palmitic acid content (12.82 ± 0.84 g/100 g lipid) and followed by EHD (12.34 ± 0.61 g/100 g), while HAD (7.83 ± 0.27 g/100 g) and MD (10.34 ± 0.56 g/100 g) showed reduced yields. The PV was significantly lower in FD and EHD indicating oxidation is minimal, while HAD had the highest oxidative values. DSC analysis showed higher glass transition temperature of the FD and EHD sample than HAD and MD sample revealing the minor structural changes. This research contributes to the valorisation of agro-industrial waste while supporting the development of eco-friendly processes for the food, cosmetic, and pharmaceutical industries.