The preparation of structured lipids by enzymatic glycerolysis is a modern approach to design low-saturated, trans-free, and sustainable fat ingredients. However, the functional properties of structured lipids greatly depend on the glycerolysis reaction conditions. Accordingly, this research aimed to optimize the glycerolysis process to obtain structured lipids with higher melting temperatures and enhanced emulsifying properties.
Optimal glycerolysis conditions for peanut oils were: 65 °C, 1:1 glycerol to oil triacylglycerol molar ratio catalyzed by 4 % of lipase B (Candida antarctica) for 16 h at 400 rpm. Also, differential scanning calorimetry (DSC) was applied to characterize the crystallization and melting behavior of peanut oils before and after glycerolysis. Nuclear magnetic resonance (1H-NMR) allowed to measure the resulting glycerol esters’ content. The microstructure of the structured and unstructured oils droplets was studied at low temperatures by scanning electron microscopy. Finally, the stability of w/o emulsions prepared with structured lipids was assessed by multiple light scattering technique. The findings demonstrated that glycerolysis increased the crystallization temperature, showing a significant increase in fat crystals even at 30 °C. The accumulation of mono- and di- acylglycerides enhanced the emulsion stability, delaying creaming and emulsion separation. Overall, the results support the use of glycerolysis to improve the thermal behavior of oils and the stability of emulsions. These findings pave the way for tailoring a lipid ingredient with nuanced functionality for the replacement of tropical fats in food formulations.