The food industry has been surprisingly accepting of the scientific findings that high levels of dietary trans fats, created through hydrogenization of oils, may raise levels of undesirable forms and levels of cholesterol in the blood. The hard part is finding substitute ingredients and new formulations that reduce trans fat content yet taste as good as their predecessors.
The problem with replacing trans fats is they work, and work well. Hydrogenation helps to solidify or stabilize a liquid vegetable oil. Hydrogenated oils produce the crisp, dry texture of a good french fry, the glaze on laminated doughs, the crispness in cookies and the savored qualities in hundreds of other favorite foods.
|In some applications, getting away from trans fats is simple; you can switch to relatively stable vegetable oils. Other oils may pose a dilemma: better mouthfeel vs. higher saturated fat content.|
Replacing trans fats with oils or shortenings containing saturated fats will work in a number of applications, but most food manufacturers adopted guidelines to not exceed the original sum of saturated-plus-trans fat content in the reformulated product.
Trans fatty acids are present in partially hydrogenated vegetable oils and shortenings. The U.S. food industry adopted them in the 1960s to replace oils containing saturated fats in products requiring solid fats for texture or to provide increased stability.
Processors answering consumer concerns with early reformulation to eliminate trans fat may have gained consumer trust. Kraft Foods Inc. reformulated or developed several new products without trans fat, including Reduced Fat Oreo, two Golden Oreo cookie varieties, Triscuit crackers (all varieties but cheddar cheese), Back to Nature organic and natural products and the Boca line of meat alternatives. Pepperidge Farm re-released its Goldfish crackers line after sans trans fat reformulation. Tyson Foods Inc. and ConAgra Foods Inc. also announced key trans fat-free products.Four Paths to Sans Trans
In certain applications, switching to relatively stable existing vegetable oils is the simplest alternative. In early 2003, Frito-Lay Inc. converted its Tostitos, Cheetos and Doritos products to trans fat-free products by frying them in corn oil.
Other oils, such as palm oil, palm kernel oil and coconut oil, offer the desirable functional traits but deliver saturated fat in place of trans fat. Even though saturated fats from plant sources do not appear to raise LDL cholesterol in the same way as those from animal fats, they contribute to the saturated count on labeling.
Modification of oils or shortenings can reduce or eliminate the trans fats. Moreover, several methods of reducing trans fat may be combined, extending the options.
Interesterification alters the three fatty acids on a fat molecule. “Interesterification rearranges the fatty acids on the glyceride backbone to get a different melt point,” explains Robert Reeves, president of the Institute of Shortening and Edible Oils in Washington, D.C. The process involves mixing fully hydrogenated oil with unhydrogenated natural oil, primarily soy, (although sunflower or cottonseed oils are also used) in a 15-85 percentage mixture and then interesterifying the mix.
Oil processor Archer Daniels Midland laid claim to being the first North American ingredient maker to use an enzyme interesterification process commercially. It released the resultant products under its NovaLipid brand, which also includes naturally stable oils and oil blends.
Another method is to reduce the amount of trans fat by altering the hydrogenation process. The process involves heating the oil at high pressure and temperature. Hydrogen is pumped in during processing while using a metal catalyst (usually nickel).
Processors may change the hydrogenation process in three ways: by switching from a nickel to a platinum catalyst; by altering the time the oil is held in the hydrogenation chamber; or by altering the temperature or pressure during hydrogenation. “All these approaches may reduce trans fat production, but they will not eliminate it,” says Reeves.
Genetic modification is a fourth option. Seed producers are developing improved oils right from the seed. Soy is most often the target oilseed, although processors also use canola and sunflower.
“A lot of the soy research involves enhancing the stability of soy oilseed by decreasing the unstable fatty acids (linolenic) or increasing the more stable fatty acids (oleic),” says Reeves. The advantage to this method is that once the desired trait is incorporated into an oilseed variety, no special processing is needed; the oil is naturally stable.
Bunge Foods has two new products from such selectively developed seeds. Nutra-Clear HS High Oleic Canola Oil is higher in oleic acid (monounsaturated fat), and lower in both linoleic and linolenic acids. Bunge’s Nutrium Low Lin, derived from a soybean developed by DuPont subsidiary Pioneer Hi-Bred International Inc. has a linolenic acid profile of less than 3 percent (compared to 7 percent in commodity soybean oil). Neither product is hydrogenated, and both are virtually trans fat-free.
The National Sunflower Association developed a new sunflower oil in cooperation with the U.S. Dept. of Agriculture, marketed as NuSun. It remains stable in frying applications without undergoing hydrogenation. The oil is 90-percent unsaturated fat (65-percent monounsaturated) and less than 10-percent saturated fat.On the Market
Danisco U.S.A., New Century, Kan., developed a trans fat-free technology that combines emulsifiers with oil to mimic the performance of shortening in most applications. These solutions, in combination with unhydrogenated oil, enable the processor to make label claims of “zero trans fats,” “less saturated fat” or “no hydrogenation.”
Nexcel Food Ingredients (www.nexsoy.com
), Springfield, Ill., recently launched its expeller-pressed Nexsoy trans fat-free soybean oil. The product is refined without the use of chemical solvents or caustics, yielding an oil with the stability of partially hydrogenated soybean oil. The Nexsoy line of oils are also available in non-GMO and organic versions.
Trans fat ingredients and reformulation pose a daunting challenge to processors and ingredient manufacturers. “A typical hydrogenated shortening supplier may have 50 or 60 shortenings to offer right now,” says Danisco’s Terese O’Neill, director of business development for emulsifiers. “It may be difficult to replace trans fat oils for many applications. But I think we will have one-for-one replacement of nearly all of these five years from now.”