Crystallization behavior of several fat blends having similar high melting triacylglycerol ratios

Ternary fat blends consisting of Palm Kernel Oil (high in Lauric acid), Palm Stearin (high in Palmitic acid) and fully hydrogenated Shea Olein (high in Stearic acid) were prepared to have a similar amount of high melting triacylglecerols at a specified temperature interval by diluting in high oleic sunflower oil. The amount of triacylglycerol species melted at 25oC or above was set at 50% in the fat blend. These blends were prepared as fatstock for shortening production. Triacylglycerol composition of the blends was confirmed by HPLC analysis. It was shown that fat blend with high Palmitic content gave an overestimation on solid fat content/SFC value. At 15oC, SFC of fat blend with high Palmitic content was 51.9% compared to 46.4% and 34.3% on fat blends with high Stearic and high Lauric contents. However, it was indicated on large deformation test using a texture analyzer that the fat blend with high Stearic content still gave the highest value on hardness followed by those of high Palmitic and Lauric contents respectively. Morphology of the crystal and network development on the fat blend with high Lauric content were also found to be distinctively different compared to those of high Palmitic or Stearic contents as measured by Polarized Light Microscopy