Fatty acids may be liberated from triacylglycerols (triglyceride) either by enzymic hydrolysis (when they are generally known as non-esterified fatty acids, NEFA, or unesterified fatty acids, UFA) or as a result of hydrolytic rancidity of the fat. Determination of FFA is therefore an index of the quality of fats.
Free fatty acids circulate in the bloodstream, bound to albumin. They are released from adipose tissue, especially in the fasting state, as a fuel for muscle and other tissues. The normal concentration in plasma in the fed state is about 0.5 µmol/L, rising to about 2 µmol/L in fasting and with exercise.
Subjects: Medicine and Health.