February 01, 2009
by Donna Berry
Few food components have confused consumers as much as fat during the past 30 years. Reduce this, avoid that, add those, eliminate these. With so many messages about dietary fats, it’s no wonder it was easier to just eat out, where, until recently, the nutritional composition of food service offerings was not revealed.
However, today’s consumer goes by the mantra, "what you don’t know can — and will — hurt you." Consumers have become ingredient savvy and are not forgiving when it comes to undesirable fat ingredients — specifically trans and saturated fatty acids.
According to the 15th Annual Consumer Attitudes about Nutrition nationwide online survey of 1,000 American adults conducted in February 2008 and sponsored by the United Soybean Board (USB), St. Louis, MO, when saturated and trans fats were directly compared, more consumers said that saturated fats were healthier; however, this figure was significantly lower in 2008, compared with 2007 (36% vs. 42%). The narrowing gulf between trans and saturated fat perception suggests the need for food companies to develop products low in both of these types of fatty acids, according to USB.
This is particularly challenging to bakers because solid fats are essential for most baked foods applications. And historically, those solid fats were obtained from animals (butter and tallow from cows and lard from pigs) and later by partially hydrogenated vegetable oils, which are concentrated sources of saturated and trans fatty acids.
"Food companies are racing to meet consumer demands for better-for-you, no-trans foods," said Frank Orthoefer, Ph.D., a fats and oils industry veteran currently consulting out of Memphis, TN. "Food formulators are responding to these demands using an arsenal of alternatives to traditional fats and oils.
"Many of the major users have already switched," Dr. Orthoefer continued. "Some have simply reformulated using commodity oils and blends with more stable nonhydrogenated versions. Others have gone the route of trait-modified oils such as the low-linolenic acid versions of soybean, sunflower or canola oils. For situations requiring greater stability, some manufacturers are using high-oleic acid versions of canola and sunflower oils. The use of blends and interesterified mixes of trait-modified oils with highly stable, naturally trans-free oils is also on the rise. To meet continuing demands, other trait-enhanced oils are in the pipeline, including high- or low-saturate options or those that are rich in omega-3s, to name just a few."
Speaking directly to baked foods, "For applications that require fats with structure and body, trait-enhanced oils serve as a fundamental building block that, in combination with other ingredients, can be built into a functional bakery shortening for baked foods," said Scott Erickson, marketing manager, Cargill, Inc., Wayzata, MN. "Such shortenings typically are softer, have more shelf life stability and have reduced saturated fat contents compared with other zero trans per-standard-serving-size offerings."
Trait-enhanced shortenings start with trait-enhanced oils. These are derived from oilseeds biotechnologically bred to be lower in unstable 18-carbon unsaturated fatty acids (linolenic with three double bonds and linoleic with two bonds) and higher in oleic acid, an 18-carbon fatty acid with a single double bond located between the 9th and 10th carbons, thus designating it an omega-9 fatty acid. These oils are blended with more solid fats, such as fully hydrogenated oils derived from vegetable seeds or oils derived from the palm fruit. For a lengthy discussion of such blending, as well as an in depth look at palm oil, see "Better Blending" in the November 2008 issue of Baking & Snack.
Mr. Erickson emphasized that as much as the food industry is moving toward being completely trans-fatty acid free, keeping saturates low must still be a priority with formulators. He explained that Cargill’s line of High-Oleic Canola Oils allows bakers to address both concerns with a single oil, eliminating the headaches of switching oils in the future.
"Cargill’s Clear Valley All-Purpose Shortening is a 0 trans fat per serving solid shortening that is perfect for cookies, biscuits, crackers, piecrusts and dry mixes," added Mr. Erickson. "The high-oleic shortening provides similar functionality, mouth feel and shelf life stability as conventional all-purpose shortenings, with the added nutritional benefits that it allows for trans-free labeling."
SATURATES GET BUSY. Saturated fatty acids differ functionally in baked applications, as well as have a different physiologic impact after consumption. Unfortunately, when it comes to the Nutrition Facts label — a purchase-influencing variable — all saturates are grouped together.
Understanding how saturated fatty acids vary functionally enables bakers to choose wisely to keep saturate levels low. "A zero-grams-trans-per-standard-serving-size shortening built upon a trait-enhanced oil foundation can be customized for a specific application using a minimal amount of specific fats that contribute to the total saturates, thereby conveying the required structure and body; this can include hydrogenated stocks, non-hydrogenated stocks and other structuring components to achieve the right texture in the shortening and the best finished baked food attributes," said Mr. Erickson. "Such shortenings are not a direct substitute for animal fats or partially hydrogenated vegetable oils, but the formulation and process changes should be minimal and the finished product just as good."
To better understand this concept, keep in mind that most cooking fats are composed of three fatty acids and a glycerol backbone. There are two generalizations that can be made about such fats. First, fats that are liquid at room temperature tend to contain more unsaturated fatty acids (one or more double bonds) than those that appear as solids. Second, as the chain length of a saturated fatty acid (no double bonds) increases, the melting point also increases. Thus, a short-chain saturated fatty acid has a lower melting point than a long-chain one. This explains why coconut oil, which contains almost 90% saturated fatty acids but with a high proportion of short-chain, low-melting fatty acids, is a clear liquid at 80°F, while lard, which contains only about 37% saturates, most with longer chains, is semi-solid at 80°F. But coconut oil’s characteristics conflict with the first generalization, which is why formulators must keep in mind that the physical state of a fat is not necessarily indicative of its degree of unsaturation.
The majority of saturated fatty acids in edible fats are lauric (12 carbons) and myristic (14), which are considered medium-chain fatty acids, and palmitic (16) and stearic (18), both long-chain fatty acids.
"Shorter chain saturated fatty acids are perceived as less healthy than the longer ones," said Monoj Gupta, Ph.D., a fats and oils expert consulting out of Richardson, TX. "Stearic acid is of greatest interest because some science suggests that stearic acid has a neutral effect on blood cholesterol levels, as compared with lauric and palmitic acids, out of which lauric is less desirable than palmitic acid. It has also been shown that the position of palmitic acid on the triglyceride molecule is critical for the impact of palmitic acid in raising cholesterol."
However, there’s also emerging science indicating that blood cholesterol levels have little correlation to increasing the risk of heart disease. "This research suggests that saturated fat has little effect on the risk of heart disease," said Gerald McNeill, Ph.D., R&D director, Loders Croklaan, Channahon, IL. "This makes palm oil, a vegetable oil with roughly the same proportion of saturated fatty acids as animal fats (which for bakers are the optimal fats), an ideal component of trans-free shortening solutions for baked foods."
DOMESTIC OPTIONS. Palm oil shortenings have proven to be one of the best immediate solutions for bakers going for zero-trans labeling. Nothing comes easy. Saturated fatty acids levels aside, another drawback for palm oil is that it’s an imported product. With an increasing number of consumers asking about the origin of food ingredients, the foreign nature of palm oil can be a deterrent for use. However, on a positive note, palm oil is not bioengineered like the trait-enhanced oils, and this, too, is a great concern for a growing number of Americans and in Europe is completely unacceptable.
An all-natural domestically produced oilseed that is emerging as a viable option for blending into bakery shortenings is cottonseed. "Cottonseed oil’s inherent composition provides good stability. It’s about one-fourth palmitic acid and virtually free of linolenic acid. It also contains ample gamma and delta tocopherols, which function as natural antioxidants," Dr. Gupta said. "Cottonseed oil readily blends with other more solid fats, including fully hydrogenated vegetable oils and palm oil."
TRAIT-ENHANCED OILS. Many bakers are finding a winner in the previously mentioned trait-enhanced oils and shortenings made from these oils. Such new varieties of oilseeds are the result of advances in biotechnology that enable scientists to alter the fatty acid profile and nutrient content of oilseeds.
The age of biotechnology is here with a vast array of improved plant varieties already commercially available, according to the Institute of Shortening and Edible Oils. The future looks bright particularly for the emergence of new oilseed varieties that will have improved agronomic characteristics, nutrient profiles and functionality in foods and food ingredients.
In the mid-1990s, Dow AgroSciences, Indianapolis, IN, developed unique canola and sunflower seed varieties through advanced plant breeding techniques that yielded oils with novel characteristics. "Chief among these properties was a unique fatty acid profile featuring a high level (greater than 70%) of omega-9 monounsaturated fats and a low level (less than 3%) of linolenic fatty acids," said Dave Dzisiak, business leader oils, Dow AgroSciences. "The new fatty acid profile, based on high omega-9 (also referred to as high oleic) content, gave them unique taste, health and performance characteristics.
"The patented fatty acid profile of Omega-9 Canola Oil makes it naturally stable and resistant to thermal and oxidative breakdown, which makes it well suited for items that need a longer shelf life such as bars, cereals and cookies," added Mr. Dzisiak. "Omega-9 Canola Oil can serve as a one-to-one replacement where other oils have been used in the past, while decreasing the bad (trans and saturated) fat content by up to 50%."
Dow AgroSciences also developed bakery shortenings made from omega-9 oils plus hardfat that can be used as a one-to-one replacement for partially hydrogenated and/or palm shortenings. "Working with manufacturers on an individual basis, Dow AgroSciences develops the best functional or label solution that works for them and their products," Mr. Dzisiak said. "These shortenings can reduce saturated fat levels up to 50% compared with palm-based shortening. They do not contain hydrogenated components and allow clean product labels."
Cargill’s Mr. Erickson pointed out that canola has the lowest level of saturated fatty acids among all edible vegetable oils, making it a clear choice as being the ideal oilseed to breed for a increased oleic acid content.
Other oilseeds can be bred to have increased oleic acid content. A new high-oleic soybean trait oil from Pioneer Hi-Bred, a DuPont business, is on-track for limited introduction in 2009 pending regulatory approvals. Based on Pioneer’s 2008 harvest results, the high-oleic soybeans contain about 80% oleic acid, significantly increasing the stability of the oil when used in frying and food processing. In addition, the high-oleic soybean oil trait has consistently demonstrated a linolenic acid content of less than 3% and more than 20% less saturated fatty acids than commodity soybean oil.
"The introduction of high-oleic and high-oleic/high-stearic soybeans will yield oils that expand the already impressive variety of applications for soybean oils," said Robert Collette, president of the Institute of Shortening and Edible Oils. "Oils from the high-oleic soybeans will provide improved stability in frying applications that use liquid oils. The high-oleic/high-stearic oils will be stable oils with added functionality for the preparation of many foods where a certain amount of solids are needed."
The baking industry is one of the most challenged when it comes to removing trans and reducing saturated fatty acids. Though promising innovations are available, the future will bring many more.
This article can also be found in the digital edition of Baking & Snack, Feb. 1, 2009, starting on Page 77. Click here to search that archive.