Technical Talk: January/February 2007
November 7, 2007
By Dr. John Michaelides
Trans fat-free baking options
Question: What new technologies allow us to replace trans fats and produce good quality baked goods?
Answer: Trans fats have been regularly in the forefront of public, health-related issues, since numerous medical research findings confirmed that these substances are seriously implicated as one of the causes of cardiovascular disease. These results are taken very seriously, not only by consumers, but also by governments. Because of this, legislation is being discussed or passed in many jurisdictions, to force food manufacturers to label their products with the trans fats contained. Some countries and municipalities have gone even further by banning all trans fats from food products or foodservice operations.
Trans fats were not developed to make people ill. From a technical perspective, the partially hydrogenated oils provide the food processing industry with a solution to two major functional issues: stability, and a wider choice of melting characteristics of fat. Hydrogenation reduces the unsaturated bonds in the fat, and, therefore, prevents or slows down the oxidation process; and this greatly lengthens the shelf life of the oil. In the process, it modifies the configuration of the fatty acids on the triglyceride molecules, thus allowing the triglycerides to form crystals, and solidify under a wide range of temperatures.
When oil is required in a liquid state, such as in frying applications, the replacement issue tends to be more of an economic one. Alternatives to partially hydrogenated oils (such as olive, peanut, sunflower and cottonseed) do exist in the marketplace, but they may be more expensive, and their shorter shelf life requires that they be replaced more frequently — and this affects the cost. Technically, these oils may not work in the case of fried packaged snacks, which require stable oils to ensure an acceptable shelf life.
New varieties of traditional oilseeds have been developed that produce oils that are much more stable, and have good functional properties in food applications. For example, Mon-santo has developed the Vistive line of soybean varieties, containing oil with a low linolenic acid profile, increasing shelf life without the need for hydrogenation. NuSun sunflower oil was developed by the National Sunflower Association and the U.S. Department of Agriculture by conven-tional breeding (i.e., not genetically modified), to specifically meet the needs of the snack food, frying and baking industry. It is a mid-oleic sunflower oil, containing monounsaturated and poly-unsaturated, as well as a low percentage of saturated fats, requiring no hydrogenation, and therefore, contains no trans fatty acids. These new oils have also been developed to accommodate the need for good texture and taste in fried foods and snacks.
The major difficulty in replacing partially hydrogenated fats is in the area of shortenings. Over the years, the hydrogenation process was an inexpensive method for developing shortenings with a wide range of characteristics and functionality. These functional properties, such as melting range and plasticity, as well other characteristics, are crucial to the food processing industry, and exceptionally important in the manufacture of baked goods.
There are various ways to achieve similar results to partial hydrogenation, but these are either more cumbersome or more costly. Chemical inter-esterification is a process that has been known for many years, but has its limitations — requiring a chemical catalyst that can be expensive or undesirable. In the last few years, enzymatic inter-esterification has been developed and commercialized by Novozymes. Although originally this process was limited to producing small batch quantities, improvements have been made, and the technology is licensed to ADM in the U.S., where commercial quantities of these shortenings are available.
Another alternative to hydrogenation is to blend different oils into formulations that can mimic the shelf life, texture and taste of the partially hydrogenated fats. One company, Smucker’s, has introduced its 100 per cent, non-trans-fat Crisco shortening that is made from blending sunflower, soy and cottonseed oil. Many brands of non-hydrogenated trans fat-free margarines are also available in the market.
Still another option to replace trans fats is to revisit the saturated vegetable fats. Such tropical oils include palm, palm kernel and coconut oils. Because these oils are of vegetable origin, they are thought not to be as harmful as butter and lard. However, these still do not give us the flexibility or the functionality that the partially hydrogenated oils do. Attempts to use these oils in baked goods has, so far, resulted in limited successes. We need to remember that replacing the trans fats with saturated fats, while less unhealthy, is still not a healthy option. Completely new technologies in developing novel fats using processes to produce structured fats are being researched, but are not fully commercialized yet.
An alternative to reducing the trans fats in our diets is to actually reduce the amount of fat in the food product. This, in turn, will reduce the trans fats. New ingredients in the market make these tasks more viable than they were in the early ’90s, when fat-free products were a complete disaster. For example, new research in water/ oil/water emulsions may result in further success in developing systems for the production of low-fat products with good mouth feel and texture, enabling food manufacturers to reduce the trans fats in their products. Many new functional ingredients are available that food manufacturers can experiment with to produce tasty, good quality, low-fat food products.
Novel oils and fats produced by new technologies will require careful evaluation for their safety and health implications, so we can avoid similar problems we are currently facing with the trans fatty acids in our diet.
For more information, or fee for service help with product or process development needs, please contact the GFTC at 519-821-1246, by fax at 519-836-1281, or by e-mail at firstname.lastname@example.org.
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