Dr. G.R. List, Contributing Editor
As trans fat nutrition labeling enters its fifth year, the oil processing and food industries reflect back on changes made due to trans fat challenges. Reformulating products to meet the less than 0.5g of trans fat per serving demand caused a reformulation revolution. Recreating foods to taste and function the same way was not a simple task. However, trans fat solutions were being addressed long before the January 1, 2006, deadline set by U.S. Food and Drug Administration (FDA) that mandated trans fat content be included on nutrition labels.
By the early 1990s, the oil processing industry began research and development of trans fat-free replacements in anticipation of the publication (first proposed in 1994, final publication in 1999) of labeling regulations which became federal law in July 2003. Many food companies began the reformulation and testing of products well before the 2006 deadline. During the period of 2003 through 2007, the number of foods having a low or a zero trans claim increased from 200 to well over 1,900. A major challenge to the industry was to accomplish the goal with commodity fats and oils, including soybean, cottonseed, sunflower, canola, corn, palm and animal fats. However, over the past five years, a number of trait-modified oils whose fatty acid compositions have been altered by plant breeding have been commercialized, and others are expected to be available within a few years. Currently, low-linolenic soybean oils are available; high-oleic soybean oils are available in limited quantities for testing, and high stearic and stearidonic acid oils will appear on the market soon. Other commercially available trait-modified oils include mid- and high-oleic sunflower and canola oils, as well as high-oleic safflower varieties. By 2008, trait-modified oils accounted for 12% (3 billion pounds) of the U.S. consumption, and it has been estimated that nearly 1 billion pounds of trans and saturated fatty acids were removed from the food supply.
On the other hand, tropical oils (palm and palm kernel) have found ever-increasing uses as trans fat replacements. Between 2002-2008, palm oil usage increased from 630 million pounds per year to nearly 2,600 million pounds per year. Moreover, during the same period, animal fats accounted for 2,800 million pounds per year. With an average consumption of 25,400 million pounds per year, the 5,600 million pounds of palm and animal fats represent 21% of dietary fat high in saturated acids. Soybean and palm oil account for 60% of the world’s edible oil production, with the former accounting for 70% of domestic consumption. Thus, trans fat replacements have focused on these two oils.
A number of oil-processing options are available for trans fat
• Chemical/enzymatic interesterification
• Tropical oils (palm, palm kernel)
• Naturally stable oils free of linolenic acid (i.e. cottonseed, corn, sunflower)
• Modified hydrogenation technologies employing changes in process variables and altered catalysts
• Fractionation of tropical oils
• Combinations of interesterification
• Hydrogenation -- Use of the trait-modified oils whose fatty acid compositions have been altered by plant breeding or genetic modification
Major oil suppliers have adopted all of these approaches to develop trans fat replacements, many of which are new innovations in the industry. An example is the enzymatic interesterification of liquid and completely hardened soybean oils. This is a new and green approach to producing trans-free margarine and baking shortenings. Several major suppliers have produced low/zero trans fats by altering process variables and through the use of chemically altered nickel hydrogenation catalysts. A wide variety of soybean-based baking shortenings are now commercially available based on this technology. Although the trait-modified oil industry is relatively young, it is growing annually, with increasing supplies and new varieties being introduced each year. For example, production of low- linolenic soybean oil has increased from 100 million pounds in 2005 to over a billion pounds in 2009. This oil has found wide acceptance in the food industry as a frying/cooking oil and in snack food applications where oxidative stability and long shelflife are considerations. Recently, mid-oleic and high-oleic soybean oils have become available and will find uses in the food service and snack food industry. Several other trait-modified soybean oils are nearing commercialization, including high-stearic and stearidonic acid varieties. The high-stearic oils will give added functionality in baking applications, and since stearic acid is cholesterol-elevating-neutral, added health/nutrition are realized.
Although the foodservice industry is exempt from trans fat regulations, a number of state, local and municipal governments have enacted or proposed legislation to ban trans fats in restaurants, school lunch programs and fast food establishments. Liquid (non-hydrogenated) oils have proven to be suitable trans fat replacements. A number of independent studies have shown that trait-modified oils perform as well as their hydrogenated counterparts with respect to fry-life, oxidative stability and consumer acceptance.
Prior to labeling regulations, margarines/spreads accounted for a significant source of trans fat. Virtually all soft products have been reformulated to zero trans. However, stick products have proven to be more difficult and typically contain 1.5-2.5g of trans /serving.
Prior to labeling, baked goods accounted for about 40% of the trans fats consumed in the United States. Baking shortenings have proven the most difficult to reformulate. A “drop-in” solution or switching from a hydrogenated to a trans free shortening may require adjustments in the process. The edible oil industry is in the process of developing improved trans fat replacements. Baking experts believe that fats and oils chemists are on a learning curve, trying to build trans-free shortening fats with guidelines developed around trans fats such as solid fat index, solid fat content, and melting points.
A look at edible oil consumption patterns over the past decade (2001-2009) shows the effect of trans fat labeling regulations on the food industry. Total consumption, broken down as animal fats (butter, lard, tallow), margarine/spreads, baking/frying, salad/cooking, and other edible uses, has remained fairly static at 21-26 billion pounds per year. Over this period, margarine consumption has shown a decrease from 11% of the total in 2000 to 5% in 2009. From 2000-2009, consumption of heavily hydrogenated baking/fats (11-44% trans) has decreased from 40% of the total to 21%. On the other hand, consumption of salad/cooking oils (1-10% trans) has increased from 44% to over 63%. Thus, trans fat labeling has caused a pronounced shift from heavily hydrogenated fats towards liquid or lightly hydrogenated. A further look at the years 2005-2009, which represent the year before labeling, the year it became effective, and the three years following shows that in 2005, baking/frying accounted for 34% of total consumption. The following year (2006), baking/frying accounted for less than 30% and has dropped continuously over the next three years, reaching 21% of total consumption in 2009. In 2005, salad/cooking oils accounted for just under 50% of total consumption, increasing to nearly 60% in 2006, and reaching over 63% in 2009.
Reducing and eliminating trans fats was a great step toward offering better products in the marketplace, but the oil processing and food industries are not done yet. Research is underway to further develop ingredients for products that will deliver greater nutrition benefits that consumers expect now, and those predicted to become dietary trends in the future.Gary R. List is a retired lead scientist at the National Center for Agricultural Utilization Research in Peoria, the largest of its major research centers. With 44 years of experience, his interests include all areas of oilseeds processing and edible oils. List began his career in 1963 and since then has published over 315 publications, proceedings, abstracts and book chapters.
From the August 2, 2010, Prepared Foods