Issue Date: July 28, 2008
Food Makers Follow Their Hearts
FOOD MANUFACTURERS are smitten with omega-3 fish oils and plant sterols. Big-name food and beverage makers such as Tropicana, Dannon, Heinz, and Nature Valley all have introduced products with encapsulated fish oils and plant sterols.
The food industry’s affection for the fatty acids was also evident at the recent International Food Technology (IFT) conference held in New Orleans, where “heart healthy” icons, including little red hearts and small blue fish, decorated many of the packaged products and food samples at the meeting’s enormous exposition.
Gregory J. Stephens, vice president of strategic consulting at the Natural Marketing Institute (NMI), a health and wellness consulting firm, described a convergence of factors that favor these beneficial, cholesterol-lowering fats. “Many consumers are taking prescription medications for cholesterol reduction, like statins, that have some pretty nasty side effects,” Stephens says. Other factors include the prevalence of obesity in the population, the aging of baby boomers, and scientific reports supporting dietary supplements.
Human health studies have shown that consumption of fish oil and plant sterols can reduce total and “bad” cholesterol levels. On the basis of those studies, the Food & Drug Administration allows food makers to report that diets including omega-3s and sterols may reduce the risk of heart disease on their product labels. Officially sanctioned health claims can give a manufacturer a coveted market advantage over competitors.
The health labels have a large potential audience. According to the Centers for Disease Control & Prevention, approximately half the adult population in the U.S. has high cholesterol, and 75% of adults have had their cholesterol levels checked in the past five years.
By NMI’s reckoning, the large number of informed consumers has helped products enriched with omega-3s and plant sterols become a major factor in “functional” foods and beverages, which provide health benefits beyond basic nutrition. Sales in the category reached $38.6 billion in the U.S. in 2007, a 12% increase over 2006. Within that segment, sales of food products enriched with omega-3 fatty acids are projected to reach $11 billion by 2011.
The focus on heart health reflects changing attitudes about the role of fat in the diet. During a symposium presentation, David Dzisiak, global oils leader for Dow AgroSciences, reported “growing label intensity because consumers are examining the amounts of fat, saturated fat, and trans fat” in their foods. Whereas food trends in the 1990s denigrated fats in favor of carbohydrates, nutritionists now draw distinctions between good fats and bad ones. Healthy fats, such as omega-9 and omega-3 fatty acids, are a major focus of Dow’s plant genetics research, Dzisiak said.
The most beneficial forms of omega-3, however, are eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), which, for now, come mainly from eating fish that, in turn, get it by consuming algae. DHA is also produced by companies such as Martek Biosciences via a fermentation process that yields a pure but expensive product that to date has been used mostly in baby formula.
Because most Americans do not consume the recommended two servings per week of fatty fish, functional foods containing fish oil may help them improve their lipid profile (the ratio of HDL, or good cholesterol, to LDL, or bad cholesterol).
But using fish oil as a food ingredient presents some technical hurdles. The fatty acids are unstable and oxidize rapidly. “Pretty soon the food will start to smell like a dead mackerel,” said Ian Lucas, vice president of Ocean Nutrition Canada, the world’s largest fish oil manufacturer, at the IFT conference.
Aside from the fishy odor problem, there are other constraints to putting fish oil in food. It needs to be incorporated into water-based mixtures, have a long shelf life, and survive wide pH and temperature ranges. It also can’t add significantly to the cost of the food or noticeably alter taste or texture, Lucas said.
The job of dealing with these constraints at Ocean Nutrition falls to Colin Barrow, vice president of R&D. His team chose a technology called complex coacervation, which encapsulates the fish oil to prevent oxidation. But getting there involved trial and error. “It took us about five years of research and 10 to 15 people to come up with this technology,” Barrow says.
The research paid off. Ocean Nutrition’s food ingredient, Meg-3, symbolized by a blue fish icon, now graces the packages of orange juice, baked products, salad dressings, cereal, and nutrition bars.
According to Barrow, the first step in processing the fish oil is deodorization to remove the smelly components. Ocean Nutrition uses proprietary antioxidants and special manufacturing processes, but as Barrow points out: “That only gets you part of the way there. You have to have more processes to stabilize the oil for use in food.”
The next step is to make a mixture of 1-µm droplets in water. Barrow’s team then adds charged polymers, usually food-grade fish gelatin, and adjusts mixing conditions to get a hydrophobic nanoparticle that is attracted to the oil. This creates a shell of polymer coacervate around the oil droplet.
The single droplets are not very sturdy, so the work continues. “Our novel process is that we agglomerate the droplets and form an outer shell,” Barrow says. “We can control the conditions to stop the agglomeration process, and we can also control the thickness of the shell.” The technique was used originally in ink-jet printing, but those microcapsules were designed to burst under pressure, and Ocean Nutrition wanted a stronger shell. “We use an enzyme that forms bonds on the outer shell so it doesn’t redissolve and break easily. It’s called enzymatic cross-linking,” Barrow adds.
This complex fish oil preparation is then spray dried and collected to form a microencapsulated powder. According to Barrow, Ocean Nutrition’s process is better than spray-dried emulsions, another common form of encapsulation, because it does not leave any of the fish oil on the outside of the particles. Oxidized oil can smell fishy even at only 0.01 ppm, he says.
MAKERS OF plant sterols, which are multiring fats rather than linear structures like omega-3s, do not have to worry about fishy smells, but they do have to contend with tricky oil-in-water formulations. Carol Lowry, senior applications scientist at Cargill Health & Nutrition, says the company’s CoroWise plant sterols are derived from by-products of corn and soybean oil distillation. But “the sterol compound is hard and waxy, making it difficult to get into food. We have to grind it into very fine particles to get an emulsified product that is water dispersible,” Lowry says.
Formulation breakthroughs are only one reason for the proliferation of sterol-enriched foods. Laura Troha, marketing manager at Cognis Nutrition & Health, traces the growth to a 2003 FDA specification expanding health claims for plant sterol and stanol esters.
The regulatory development opened up the playing field to the free form (nonesterified) of sterols and related stanol compounds and expanded the range of products that may bear the health claim. “Suddenly, we went from only spreads, dressings, and snack bars to the extensive diversity of fortified food and beverage products that we see now,” Troha explains. “And the list continues to grow.”
Cognis manufactures plant sterols under the trademark Vegapure, but unlike Cargill, it combines free sterols with skimmed milk powder to avoid gritty textures and clumping.
After a functional ingredient survives its insertion into food, it needs to survive a trip through the body to ensure that consumers get the advertised benefit. When it comes to encapsulated, heart-healthy fats and oils, the nutrient’s bioavailability is limited by its solubility in water or oil, the type of encapsulation polymers used, and the surface area of the particle, according to Edgar J. Acosta, a professor in the department of chemical engineering and applied chemistry at the University of Toronto.
In a talk at the food meeting on colloidal and nanostructures in food, Acosta reported that uptake by the body is a function of absorption rate, dose, and the amount of time the substance stays in contact with the intestinal wall before dissolving. “You need to make the ingredient stick to the intestine by increasing the residence time, which will increase the absorption amount,” Acosta said.
The research supporting the formulation and delivery of fatty acids and sterols is not visible to the consumer, so manufacturers pursue trademarks to help signal that a product is enhanced for health. According to NMI’s Stephens, “Everybody wants to have the ‘Intel inside’ kind of branded ingredient.” But ingredient makers need to spend money to build awareness for this strategy to work. Stephens cites Ocean Nutrition’s Meg-3 and Cargill’s CoroWise as two successfully differentiated brands.
Although functional foods containing fish oil and plant sterols have been embraced by consumers, their overall effect on human health is not yet known, according to Alice H. Lichtenstein, professor of nutrition science and policy at Tufts University and lead author of the 2006 American Heart Association diet and lifestyle recommendations. Lichtenstein says the impact on health will depend on how consumers are interpreting health claims and if they change their overall eating behavior.
“What are the tradeoffs? Will they do other things that are heart healthy?” Lichtenstein asks. After all, she points out, “if you are eating fish for an entrée, you are not eating a hamburger in that meal. It’s the whole behavior that one needs to think about.”
Much more data are available about dietary supplements than about functional foods, Lichtenstein says. When patients take a specified amount in a supplement, it is easier to track the results. The American Heart Association recommendations note the health benefits of fish oil and plant sterol supplements for patients with documented coronary heart disease and high blood levels of triglycerides.
But NMI’s Stephens points out that supplements are not how most people get their daily nutrition, so researchers continue to work to sneak functional ingredients into a wider range of foods. The holy grail of encapsulation, according to Ocean Nutrition’s Barrow, is a particle that is so small—less than 100 nm in diameter—that it does not reflect light. Think a new line of heart-healthy water.
Consumption of fish oils and sterols can be a sustainable trend, but “the food has to be palatable and have good sensory attributes,” Stephens says. “We have found that consumers will not compromise taste for health, and they won’t spend a lot more.”
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