free fatty acids, oil, nanoparticles, feed


Unprocessed crude oils consist of some amount of triglycerides as well as free fatty acids (FFAs). FFAs are virtually absent in oils from living tissue. They are formed by enzymatic action after the animal has been slaughtered. Hydrolysis of ester bonds in lipids, which results in the formation of FFA from the triglycerides, may be caused by enzymatic action, heat, or moisture. This release of short-chain fatty acids is the reason for rancid flavor and odor. Furthermore, the presence of FFAs can self-catalyze and release more FFAs from triglycerides. FFAs are susceptible to oxidation, which leads to oxidative rancidity. This paper addresses the removal of FFA by adsorption with magnetic nanoparticles as a way to improve the feeding value of processed or rendered oils.