Measurement of the size distribution of fat crystals using a laser particle counter

A new method that uses a laser particle counter has been developed to measure the size of fat crystals. The fat crystals were suspended in isobutanol in the ratio of 1∶25,000. The solid and liquid fat recovery after being in contact with isobutanol for 24 hr, fatty acid composition of the solid and liquid fractions, DSC melting behavior and polarized light microscopy proved that isobutanol did not affect the structural integrity of the fat crystals. The mean crystal size of commercial shortenings ranged from 5 to 9 μm. The isobutanol suspension method makes it possible to quantitatively separate the solid and liquid components of a fat. It also provides a convenient way of preparing fat crystals for scanning electron microscopy.