Sorting fat from fiction

Prepared Foods, Oct, 2002 by Kellie Fischer

Regulations on trans fatty acid labeling are expected shortly. Tactics to replace hydrogenated or partially hydrogenated fats with non-hydrogenated oils depend on the application. Lessons learned from fat replacement efforts may apply.

First, there was the transition from animal-based to plant-based oils and fats. Next, it was the reduction of tropical oils such as palm, palm kernel and coconut to reduce the level of saturated fats. Now, the trend is to remove or reduce the level of trans fatty acids. Trans fatty acids occur naturally in products such as meat, dairy and some baked goods; but, hydrogenated oils contribute the majority of trans fatty acids to our diet.

Partial hydrogenation originally was developed to improve oil stability and change liquid oils into semi-solids so that fats and oils could be used over a broader range of applications. As the understanding of the medical implications of trans fats evolves, what does it mean to those who develop food products?

What About Trans Fatty Acids?

Consumers are being educated by organizations such as the American Heart Association, Dallas, Texas, to select products containing more non-hydrogenated oils and less saturated fats. In the dilemma of "butter vs. margarine," camps are split as to which is the "lesser of the two evils." A study in the December 6, 2000 issue of the Journal of the American Medical Association indicated that "margarine is a more heart-healthy choice than butter." Margarine contains no dietary cholesterol but does contain trans fatty acids.

In 1999, as a result of studies reporting the tendency of trans fatty acids to raise total blood cholesterol levels, the FDA proposed to amend its regulations on nutrition labeling to require that the trans fatty acids levels in a food be included in the amount and percent Daily Value declared for saturated fatty acids. Some reports also indicated that trans fatty acids tended both to raise LDL-cholesterol levels and lower HDL-cholesterol levels. A more recent study conducted by the Institute of Medicine, Washington, D.C., concluded there is no safe level for trans fatty acids so it would not specify an upper limit.

The FDA recently announced that a final rule requiring that the amount of trans fatty acids in foods be listed on labels is pending. This ruling could be finalized by as early as this fall or early next spring. Food producers will be required to list the grams of trans fat on a separate line in the nutrition facts on labels, but trans fats will not be included in the Percent Daily Value. Because trans fat occurs naturally in meat, dairy, baked goods and other products, a total elimination would require such a drastic change in consumers' diets that other health issues may emerge as a result. Thus, the recommendation from the Institute of Medicine's report is to be "as low as possible while consuming a nutritionally adequate diet."

Impact on Formulations

From a product development standpoint, changing the composition of a fat or oil can be as difficult as replacing or reducing a product's fat level. If only minor alterations are required, such as when small quantities of highly concentrated lipids (e.g., omega-3 fatty acids) are added to enhance the nutritional quality of a food product, complications may be fewer than reformulating due to changes in fat quantity or type. (See sidebar.) In contrast, when major changes in fat sources or composition become necessary, the magnitude of difficulty can be similar to that presented by fat replacement and reduction efforts.

When fat reduction efforts were at their peak, the primary formulation tools available for developers were to: 1) replace the lost attributes of mouthfeel and moistness imparted by fats, 2) manage the extra moisture that was usually added and 3) mimic the functional and structural elements provided by the replaced fat. By contrast, replacing or reducing the quantity of specific components of fats may require new oil sources or blending fully saturated fats with unsaturated, non-hydrogenated oils. Development of specialty fats or biotechnological advances also is necessary, since many of the methods utilized to reduce trans fatty acids can increase the level of saturated fatty acids.

What does this mean for research and development scientists? Much of their fate appears to lie with companies producing shortenings and oils. Patents obtained since 1999 focus on the replacement or reduction of trans fatty acids for use in margarines and spreads. Esterification methods and transgenic plants have been used to reduce the need for hydrogenation. Interesterification permits "tailoring" of triglycerides to produce specialty fats with very specific melting point ranges. Unfortunately, these processes tend to increase the amount of saturated fat by utilizing palm and palm kernel fractions or by increasing the amount of palmitic acid in the case of the transgenic corn oil.

Suppliers have noted that there are several factors that have limited the application of many of these methods. According to the Institute of Shortening and Edible Oils, Washington D.C., "functionality, technology, availability, economics and strength of scientific evidence" are among the reasons that the introduction of low or no trans fat alternatives have been limited. The National Center for Agricultural Utilization Research (NCAUR) in Peoria, Ill., developed a low-trans hydrogenation method and claims it can make a product with less than 10% trans fatty acid content, suitable for use in margarine and other spreads.