The recent New York City ban on trans fats has brought fats back into the spotlight only a year after Food and Drug Administration’s (FDA) mandatory labeling rule. However, trans fats are only the latest focus of a more basic concern about dietary fats that has triggered several trends. Formulation paradigms will continue to shift as product developers keep searching for the best strategies to address health concerns while creating appealing products and avoiding unintended effects.
FATS IN BAKING
The baking industry originally turned to partially hydrogenated oils when concerns were raised about the saturated fat content of animal fats and tropical oils. Partial hydrogenation yields solid or semisolid fats with a higher melting point and better stability that quickly became the solution of choice for reduction of saturated fats. Unfortunately, this led to a dramatic increase in consumption of trans fatty acids (TFA) that became a concern when several reports linked TFA consumption with cardiovascular disease (CVD).
Nowadays, it is well accepted that TFAs increase blood levels of lowdensity lipoproteins (LDL) or "bad cholesterol" and particularly the small, dense LDL particles that are the most damaging to arteries. In addition, TFAs lower the levels of highdensity lipoproteins (HDL) or "good cholesterol" that can scour blood vessels of bad cholesterol and take it away to the liver for disposal. High intake of TFAs increases the tendency of blood platelets to clump and form artery blocking clots and fires inflammation implicated in heart disease, diabetes, stroke and other chronic conditions.
In the US, FDA estimates that baked foods are the primary source of these compounds accounting for 40% of the daily intake. Thus, the baking industry has been the hardest hit by the move to reduce TFAs. This is not easy since bakery products rely heavily on the functionality of partially hydrogenated fats. For years, pastries and cookies have owed their lightness, flakiness and crispiness to aeration accomplished only with saturated fats or partially hydrogenated oils.
There are several ingredient options that range from alternative fats and substitutes to fat replacement ingredients that will help formulate products with similar or better functionality and consumer appeal than their transfat-rich counterparts. However, each alternative will have to be considered on a case-by-case basis since solutions are not one-size-fits-all. Considerations include not only functionality in products but also technological feasibility, labeling issues, cost and consumer acceptability.
The first and most obvious alternative would be going back to animal fats — butter and tallow. This may be challenging because of the cost and reliability of supply in addition to the saturated fat concern. New blends with vegetable oil such as Nextra, a tallow/corn oil blend created by Source Food Technology, Durham, NC, with licensed technology from Brandeis University, Waltham, MA, may be a good alternative for fried products because it delivers a longer fry life and keeps foods hotter longer.
Tropical products such as coconut and palm oils are now being revisited. Palm oil has about 50% saturated fat and is also rich in oleic acid. It has good functional properties because of its palmitic acid content that forms very small, stable crystals that give a very smooth texture and entrap small air bubbles in baked products.
Fractionation of tropical oils, a physical process where the oil is heated and cooled slowly to separate different crystals, can yield a range of products with unique functionality. The fractionated saturates, rich in palmitic acid, are ideal for creamy texture and stable aeration. Loders Croklaan, Channahon, IL, has introduced Sans trans cooking oil and the Freedom series, which are palm oil-based alternatives for different frying, baking and chocolate-based applications.
Some studies claim that the original concerns regarding the effect of tropical oils on CVD were largely unfounded and actually suggest that coconut oil increases HDL cholesterol making it a good alternative when a bit of hard fat is needed.
Demand from consumers and bakers for trans-free, nonhydrogenated fats led AarhusKarlshamn USA, Inc., Port Newark, NJ, to combine the attributes of no-trans with low saturates. The company is a leader in specialty fats and, many years ago, was the first to produce a cocoa butter substitute using fractionated palm kernel oil.
"The [trans-free] approach that Aarhus took was to develop a product that would allow the use of liquid oils from any source and design a fat ingredient that delivers the functionality the baking industry demands," explained Ed Wilson, AarhusKarlshamn’s sales and marketing director.
The result was EsSence nonhydrogenated shortening blends, which not only eliminate trans fats but also significantly lower saturated fats compared with competitive oils. This blending approach works with the customer’s choice of liquid vegetable oils: canola, soybean (including low-linolenic soybean), sunflower and safflower.
"The issue is now saturated fats," Mr. Wilson continued, explaining that some EsSence blends contain only 20% saturated fats. When used in sandwich cookies, for example, this translates to
1 g or less of saturated fat per serving. REARRANGING FATTY ACIDS Fully hydrogenating vegetable oils yields a hard, waxy fat. When these products are blended with unprocessed liquid vegetable oil, a semi-soft compound is obtained. The process known as interesterification rearranges the fatty acids in oils to allow the blend to function like partially hydrogenated oils. Because partial hydrogenation is not involved, trans fats are not created in this process, and the taste, texture and flavor of foods are maintained.
Interesterification can be achieved either chemically or enzymatically. Enzyme catalysis is more efficient because the controlled reaction can modulate final product characteristics to yield different functionalities. During this process, fatty acids are cleaved from the glycerol backbone and then reattached in different positions, thus influencing the melting behavior.
ADM, Decatur, IL, has worked with enzymatic technology from Novozymes AS, Franklinton, NC, to produce NovaLipid, a good alternative with zero to low trans fats that can be tailored individually for applications in ice cream, margarines, bakery fillings and candy coatings. The resulting fatty acid arrangements are actually found in nature because the shortenings obtained through this process are based on stearic acid and mono- and polyunsaturated fatty acids. Therefore, interesterification gives a full range of triglycerides that are similar to those found in cocoa butter, palm oil and animal fat.
One of the main objectives of partial hydrogenation is to reduce linolenic acid content to increase stability. Oilseeds developed with friendlier fatty acid profiles through selective breeding may be part of the solution. Natreon from Dow AgroSciences, Indianapolis, IN, is a stable canola oil that is high in healthy monounsaturated fatty acids, low in saturated fatty acids and virtually trans fat free.
Monsanto, St. Louis, MO, developed Visitive, a low-linolenic strain of soybeans that has valuable functional attributes, because the reduction of linolenic acid (less than 3%) reduces or eliminates the need for hydrogenation. The Trisun series of identitypreserved high-oleic sunflower by Humko Oil Products, Memphis, TN, is rich in oleic acid (80%) and low in saturated fat and does not need hydrogenation or deodorization. These products have a clear, neutral flavor and can be labeled simply as "sunflower oil."
In February 2005, Germany’s Bayer CropScience announced an agreement with US Cargill to bring a higholeic rapeseed oil that will not require hydrogenation to US and Canadian markets in 2007. These companies join efforts by US Bunge, ADM and Dupont that have launched various brands of zero or low trans oil.
Other solutions include the use of fiber products such as Z-Trim and Oatrim developed by the US Department of Agriculture Agricultural Research Service (USDA-ARS). According to USDA, Z-Trim mimics fat in food preparation so well that most people cannot tell the difference between the high-fat product and the naturally lower fat, higher fiber version, so it can be used to make healthier alternatives of favorite foods such as cookies and cakes. Products formulated with Oatrim can also reap the benefits of cholesterol-reducing beta-glucan naturally present in oat fiber.
California Natural Products, Lathrop, CA, has developed a rice-based fat replacer. The starch granules in rice syrup solids act like solid fat and mimic the slippery creamy mouth feel of fat globules, thus helping create texture in baked products. This product can be labeled as "rice syrup solids" making it a clean-label alternative.
Other trans-fat solutions include the use of ingredients that enhance performance of trans-free oils. For example, Copenhagen, Denmark-based Danisco’s trans-free solutions include the Grindsted Crystallyzer Emulsifier blends designed to improve the crystal- lization and performance of trans-free fats and optimize production capacity of bakery and filling fat producers. Cognis, Düsseldorf, Germany, has also recently launched the emulsifier system Lamequick CE7203, claiming that it can help food makers use nonhydrogenated fats in whipping agents to achieve food foam volume and firmness in addition to a pleasant mouth feel.
GOOD FAT, BAD FAT, BETTER FAT
Lipids have managed to survive fads, praise, love and hate and are now emerging beyond the good fat/bad fat story. Recognition that some fats, even naturally occurring trans fatty acids such as conjugated linoleic acid (CLA), are actually desirable has brought back some glory to this mangled nutrient. CLA, an 18-carbon fatty acid, has two double bonds and is naturally produced by microbial hydrogenation of linoleic acid in ruminant stomachs and is unlike trans fatty acids produced through industrial hydrogenation. CLA, or rumenic acid, has been linked to reduction of risk of several types of cancer such as prostate, colorectal, stomach, lung, skin and breast by slowing precancerous-cell growth and promoting tumor shrinkage. Some studies have shown that CLA helps burn fat, enhance muscle tone and increase nutrient absorption.
CLA is excluded from FDA’s definition of trans fats, basically because its two double bonds are conjugated, separated by a single bond. FDA defines trans fats as all unsaturated fatty acids that contain one or more isolated (nonconjugated) double bonds in a trans configuration. Since many people are consuming less meat and dairy fat and modern livestock feeding emphasizes grains over grass reducing linoleic acid intake, the intake of naturally-occurring CLA is limited. Supplement manufacturers suggest the inclusion of CLA in formulas at around 1.5 g per serving to obtain such benefits.
The popular omega-6 and omega-3 fatty acids are polyunsaturates of different chain lengths with double bonds on the sixth and third carbon from the methyl or omega end of the fatty acid, respectively, and are perhaps the best known "health promoting" fats. When consumed, the body transforms these essential fatty acids into longer and more highly unsaturated fatty acids such as arachidonic acid (AA), alpha-linolenic acid (ALA), docosahexaenoic acid (DHA) and eicosapentaenoic acid or EPA.
The Institute of Medicine (IOM) of the National Academy of Sciences has set adequate dietary intakes of 11 to 14 g per day of linoleic acid and 1.1 to 1.6 g per day of ALA. Addition of oils to the daily diet such as flaxseed, soybean and canola as well as walnuts and sesame seeds are excellent options.
Purified omega-3 such as Denomega 100 Omega-3 Powder by Denomega Nutritional Oils, Sarpsborg, Norway, and ROPUFA by DSM Nutritional, Heerlen, The Netherlands, are also good functional ingredients for bread, biscuit, cookie and bar formulations.
When consumers need additional help to lower cholesterol levels, products using ingredients such as plant sterols and stanols and their esters can be the solution. Phytosterols, compounds derived from all-natural plant sources and chemically similar to cholesterol, have been shown to block cholesterol absorption, thus leading to its elimination from the body. In fact, FDA allows health claims indicating that phytosterol-containing products can lower the risk of heart disease. The claim also covers plant stanols, which are chemically related to sterols in both the esterified and unesterified forms.
Baking applications of phytosterols include bread, cookies and health bars; and ingredients are available from different sources. Cargill Health & Food Technologies, Minneapolis, MN, manufactures and markets CoroWise, a line of plant sterol products processed to address specific formulation needs. According to information provided by Cargill, daily intake of at least 0.8 g of free plant sterols as a part of a diet low in saturated fat and cholesterol is recommended to provide significant cholesterol-lowering benefits. Other sources of phytosterols include Reducol by Forbes Meditech, Inc., Vancouver, BC, and ADM’s CardioAid.
It is obvious that concerns over dietary fats and cholesterol and their relationship with cardiovascular health and disease are here to stay. Formulation will continue to be a balancing act to address consumer health concerns while delivering cost-effective, appealing products.
It is important to conclude that not all fats are created equal, and while trans fat is only one of the contributors to CVD, consumption of healthy fats and supplements is only part of the solution to this complex problem. A holistic approach that includes healthier dietary habits and increased physical activity to actually reduce individual risk is needed to complete the health crusade.