By Marilyn Stieve, Contributing Editor
Initially introduced into the U.S. by colonists to provide fiber for clothing, flax use has since expanded into a broad range of food production applications, including breadings, baked goods, sauces and beverages. From its humble origins as one of the first domesticated plants, flax is now big news. According to the Agricultural Marketing Resource Center (AgMRC), Iowa State University, Ames, IA, last year alone, the United States produced nearly 2.8 million bushels of flax, valued at $38.6 million. The United States is one of the big-four producers, with 80% of the worlds flaxseed grown by Canada, China, the United States and India. Flaxseed offers a pleasant, nutty flavor and considerable health benefits for consumers, while manufacturers turn to it for its numerous functional benefits for food and beverage formulations.
What makes flax so appealing?
From a nutritional perspective, flaxseed contains oil (predominantly "healthy" polyunsaturated fatty acids), as well as 20 grams protein and 28 grams dietary fiber per 100 grams (Flax Council of Canada). And, its an important emerging food ingredient due to its rich content of omega-3 alpha-linolenic acid (ALA) fatty acids, lignans and fiber (Critical Reviews in Food Science and Nutrition, 2011; 51(3):210-222).
Flax contains two essential fatty acids (EFAs): ALA and linoleic acid (LA), which provide omega-3 and omega-6 fatty acids, respectively. EFAs, including ALA omega-3s, provide a number of health benefits, including those associated with cardiovascular health. As such, flax ingredients that contain high levels of omega-3s are increasingly being used in a variety of food applications to deliver significant levels of EFAs and their associated health benefits.
Flaxseed provides one of the richest vegetarian sources of ALA available, containing more than five times the ALA content of most other common plant oils.
ALA is the only true essential omega-3 fatty acid required in the diet, since it cannot be synthesized by the body (Nutrition Reviews, 2008; 66(6):326-332). Its critical to human health, particularly for normal growth, development, reproduction and vision. ALA can be converted into eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) omega-3 forms through inherent metabolic pathways (American Journal of Clinical Nutrition, 2010; 92( 5): 1,040-1,051), creating comparable levels of EPA and DHA to those obtained from fish oils. The conversion of ALA into its longer-chain metabolites is important as it allows consumers to reap the added health benefits of EPA and DHA. However, while ALAs conversion to EPA and DHA is important to ensure delivery of the health benefits of those fatty acids, ALA itself has been shown to have significant health advantages. For example, ALA protects against cardiovascular disease by altering the omega-3 fat content of cell membranes, making them more flexible and improving functionality (Journal of the American College of Nutrition, 2002; 21:495-505).
Plus, ALA has been proven to dampen inflammation, which is a feature of many chronic conditions, such as coronary heart disease, stroke and cancer (American Journal of Clinical Nutrition, 2007; 85:385-391), as well as help to reduce arrhythmia (American Journal of Clinical Nutrition, 2003; 78(Suppl):640S-660S).
According to the Flax Council of Canada, Winnipeg, Manitoba, flax is also an important source of both insoluble and soluble dietary fiber, with just one tablespoon of milled flax providing as much total dietary fiber as one slice of whole-wheat bread. Fiber is listed as one of the most underconsumed nutrients in the Dietary Guidelines for Americans 2010, so Americans, in particular, are advised to add more fiber to their diets to help maintain healthy bowel function, lower blood cholesterol, and protect against cancers of the GI tract. Flax provides a great opportunity to achieve this.
Flax in food
With food safety top-of-mind for food manufacturers, leading companies in the flaxseed industry have responded by developing a heat-treatment process that is 5-log validated. This intensive heat-treatment process ensures microbial safety while protecting the integrity of the flaxseed and maintaining the shelf life at two years. The 5-log kill process replaces the limited kill steps previously used during the manufacture of flaxseed applications, such as beverages, granola and nutritional bars, and peanut spreads.
As foods evolve to offer significant health benefits for the mainstream market, the biggest challenge for food manufacturers is creating foods that also meet consumers demand for great-tasting products. The nutty and toasted sensory profile of high-performance flaxseed-derived ingredients provides manufacturers with a tasty way of adding healthy functionality to baked goods, cereals and bars, as well as dough applications, such as pizza and tortillas. In tortillas, flax ingredients can improve the rollability, spread, flow and yield. Flax does not adversely affect the taste of most foods, and is particularly suited to fortifying baked goods. In addition, cleaning and stabilization technologies guarantee thermal and oxidative stability of end products, offering a shelf life of up to two years. From an omega-3 formulation perspective, if properly milled, the omega-3-rich oil in flaxseed is more stable than in fish oil and less prone to oxidation, presenting manufacturers with a stable and flexible approach to fortification.
A unique property of flaxseed is that it contains a gum matrix, known as gum mucilage. Using specially developed processing systems, functional flaxseed products have now been developed that exploit this inherent property. Flax ingredient solutions with strong water-binding capabilities and gum mucilage can replace gum systems in food applications, such as gluten-free baked goods, where it can improve both texture and shelf life in gluten-free tortillas, sheeted doughs, batters, breadings, sweet baked goods and fresh breads. Gums or hydrocolloid systems that help manage moisture content are essential for gluten-free baked goods, since the flours that can be used tend to dry out food formulations. Plus, with the current global guar gum shortage showing no signs of ending, food manufacturers are increasingly turning to alternative systems such as flax-derived hydrocolloid ingredients for cost-effective functionality.
Flax-based ingredients can be easily incorporated into a wide variety of foods, including beverages, pasta, cereals, dressings and sauces, as well as certain processed-meat applications. In beverage formulations, for example, selecting very finely milled flaxseed-derived ingredients provides a smooth texture for ready-to-drink or ready-to-mix fortified beverages, without compromising the taste or texture. And, as an added benefit, manufacturers can tap into the clean-label market, as flaxseeds can be listed simply as flaxseed" while contributing to health claims.
The proven health benefits of flax, and the corresponding consumer interest, has led to the further development of high-performance flax-derived functional and nutritional ingredients. Flaxseed-derived ingredients provide the multifunctional benefits of high ALA and fiber content, an excellent sensory and functional profile, and are well-suited to convenient delivery formats such as baked goods and bars. In this way, manufacturers benefit from the ease of formulating with omega-3 and fiber, or for specialist functionality such as gluten-free properties, while consumers gain significant health and nutritional benefits. A win-win all round.
Marilyn Stieve is business development manager for flaxseed at Glanbia Nutritionals, Fitchburg, WI. She has been in the food industry for more than 20 years, working in research and development, marketing and sales. Stieve has a B.S. in food science from University of Wisconsin, as well as an MBA from Keller Graduate School. For more information, contact the author at [email protected], or log on to glanbianutritionals.com/products/flaxseed.