Combined Short-Path Distillation and Solvent-Assisted Crystallization of Beef Fatty Acid Methyl Esters

Solvent-assisted crystallization has previously been employed to remove long-chain saturated fatty acids (≥ 18 carbons) from animal fat to improve its cold temperature biofuel properties. The same technology can be used for removing long-chain saturated fatty acids (SFA) from animal fats for human consumption, but SFA remaining (i.e., 14:0 and 16:0) are more atherogenic than longer chain SFA. In the present study, an easy and efficient method was developed using short-path distillation prior to solvent-assisted crystallization for the more complete removal of SFA from beef tallow, and for the first time reports the distillation and crystallization behavior of polyunsaturated fatty acid biohydrogenation products (PUFA-BHP). Shorter chain SFA methyl esters (i.e., 14:0 and 16:0) were efficiently removed at 90 °C, 9.3 Pa, with a rotor speed of 70 rpm and either two cycles of distillation at 90 drops/min or three cycles at 110 drops/min. Stearic acid (18:0) was then effectively removed by crystallization at −20 °C using a sample to methanol ratio of 1:10. The remaining fraction enriched with PUFA-BHP (i.e., rumenic acid, c 9, t 11-18:2, and its precursor vaccenic acid, t 11-18:1) have potential use in disease model (i.e., cell culture and animal) studies to help further elucidate their bioactivity and mode of action, and may in the future have functional food or nutraceutical potential.