Food Lipids: Chemistry, Nutrition, and Biotechnology

6
Methods for trans Fatty Acid Analysis
RICHARD E. MCDONALD
U.S. Food and Drug Administration, Summit-Argo, Illinois
MAGDI M. MOSSOBA
U.S. Food and Drug Administration, Washington, D.C.
I. INTRODUCTION
trans Fatty acids are present in a variety of food products; some are derived from
natural sources, such as dairy products, but most come from products that contain
commercially hydrogenated fats. The nutritional properties of trans fatty acids have
been debated for many years, particularly with respect to the amounts of low density
and high density lipoprotein (LDL, HDL) contained in serum. Some studies have
shown that trans fatty acids elevate levels of serum LDL cholesterol and lower HDL
cholesterol [1–3]. Such results drew a great deal of media attention, which led to
several requests for the U.S. Food and Drug Administration (FDA) to make labeling
of trans fatty acids mandatory on food products. There have also been requests to
either ban these substances or to impose strict limitations on their use. However, a
comprehensive report of an expert panel convened by the International Life Sciences
Institute [4] concluded that food products containing partially hydrogenated fats are
good substitutes for traditional fats rich in saturated fat, but are not good substitutes
for unhydrogenated vegetable oils. The report also concluded that the overall effect
of hydrogenated fat on serum cholesterol levels depends on the consumption of
saturated, trans/cis-monounsaturated, and cis-polyunsaturated fatty acids. The authors
recommended more research to better understand the effects of trans fatty acids
on serum lipid concentrations and coronary heart disease. We recently discussed both
the nutritional and food labeling issues associated with trans fatty acids [5].
trans Fatty acids in the diet are mainly derived from partially hydrogenated
vegetable oils (PHVOs) and ruminant fats. While PHVOs have been reported to
Copyright 2002 by Marcel Dekker, Inc. All Rights Reserved.