Effects of emulsifiers on crystallization properties of low-melting blends of palm oil and olein

The effects of sorbitan tristearate (STS) and soy lecithin on palm oil and on palm olein blends with low slip melting points for fluidized palm oil formulation, by temperature cycling, were studied. The dispersion of crystals in the liquid influenced the viscosity and the solid fat content (SFC) of the product at the end of the temperature cycling treatment. The fluidized palm oil formulations were melted at 80C. STS and lecithin were added; the formulation was cooled at 20C for 80 min, was heated at 30C for 45 min and was cooled again at 20C for 30 min to reproduce the production temperatures of fluid shortening. The crystal development, SFC and viscosity were determined. Fine crystal aggregates were produced using 0.09% STS and 0.03% lecithin. Generally, however, lecithin produced uniform crystal aggregates. Crystal growth in the absence of emulsifier was limited, while the addition of emulsifiers increased the growth. Lecithin produced higher SFC than STS at 0.03%. STS was a crystal inhibitor in blends with much lower melting triacylglycerol. Lecithin and STS had little effect on viscosity: 0.06 and 0.09%, respectively. Thus, emulsifiers could be useful agents for controlling crystallization in fluidized palm oil formulations.