Effects of branched-chain fatty acid triacylglycerols on the crystallization of palm oil-based blends

Abstract

The aim of this study was to assess how branched-chain fatty acid triacylglycerols (BCFA-TAG) at different concentrations (1–10 g/100 g) affect palm oil-based blend PO-PS (palm olein/palm stearin = 7/3, wt/wt) crystallization and other related performance. The addition of BCFA-TAG significantly affected the crystallization of PO-PS by accelerating the onset of PO-PS crystallization through promoting the nucleation of PO-PS crystals while delaying the growth of the crystals as a whole. The reduction in t_1/2 provided good evidence of the delay, with the effect of high concentrations (10 g/100 g) being the most pronounced. Adding BCFA-TAG to PO-PS reduced its solid fat content (SFC), with a more significant effect at higher concentrations (5, 8, and 10 g/100 g). After 48 h of crystallization at 25°C, BCFA-TAG induced a more compact and orderly crystalline network of PO-PS with an increase in space-filling, resulting in an increase in hardness. The crystal density of the higher concentration samples (PO-PS + 10% BCFA-TAG) decreased over storage time, suggesting a crystal dilution effect of high concentrations of BCFA-TAG. The PO-PS + 10% BCFA-TAG sample maintained the β′ crystalline form throughout the 30 days of storage without conversion to the β crystalline form, thus showing a positive effect of BCFA-TAG in alleviating the post-hardness of the palm oil.