Tiny Secrets

Originally Published NO May 2010

As more people recognize the need to make healthier choices in their everyday diet, customers all over the world are turning to better-for-you foods, making the functional-foods market one of the most successful and fastest-growing areas in the food industry in recent years. The growing demand has not gone unnoticed by food and beverage producers, who, seeking to get their fair share of this promising market, are creating products that offer customers extra value by incorporating healthy ingredients in new applications.

Ingredients currently being used in functional foods include vitamins, minerals, antioxidants, probiotic bacteria, and nutritional oils and polyunsaturated fatty acids-in particular, omega-3. Every day, new scientific studies emerge highlighting the health benefits of these ingredients.

While the list of active ingredients that can potentially be used in functional foods is long, it rapidly shortens once the sensitivity of some of these ingredients is taken into consideration. Adding a functional ingredient to a food or beverage application can be a big challenge, because ingredients can be very sensitive-and, in some cases, highly reactive.

In fact, many of the healthy ingredients being used in functional-food and beverage applications are unstable and prone to oxidation. This can lead to "off" flavors and a change of the sensorial properties of a final product. For instance, the addition of small amounts of iron to a product can potentially change the color of a product and add a metallic, rusty taste. Also, the incorporation of nutritional oils can lead to separation in a product, and fortifying milk with omega-3 can result in an unpleasant fishy taste.

Masking the smell and taste of an active ingredient to ensure that the ingredient blends in nicely with the desired application is a huge challenge. It leaves companies searching for solutions that:

• Protect active ingredients from oxidation and degradation over the shelf life of the final application.

• Facilitate handling and processing of functional ingredients. 

• Protect sensitive ingredients from reacting with other ingredients.

• Inhibit separation in the final product.

• Ensure a controlled release of the healthy ingredients.

Microencapsulation

In order to tackle these challenges, food producers have turned to microencapsulation, a process in which droplets or tiny particles are enclosed by a coating, forming a uniform wall that protects an active ingredient. Over the years, many microencapsulation technologies-both mechanical and chemical-have been developed. A few of those commonly used by the food and beverage industry are described below:

Spray drying is a mechanical form of microencapsulation used widely in the food industry. An active ingredient is mixed with a solution comprising a microencapsulation coating material. The resulting solution or emulsion is then atomized and subjected to a rapid drying process during which water dries off, leaving behind microencapsulated particles. One drawback to this technique is that the process may not protect the entire active ingredient, but rather may leave oil- and water-soluble particles on the surface exposed to oxidation or degradation.

Fluid bed coating is another mechanical microencapsulation technique that can add an extra layer of protection to microencapsulated particles by further protecting particles on the surface from oxidation. An active ingredient floats in the air, is sprayed with coating, and then is dried. This process can be repeated to increase the wall thickness of a coating. However, due to the extra layer of protection, resulting particle sizes can be rather large, between 80 µm and 2 mm, which can make it challenging to homogenously distribute the microencapsulated particles into the final application.

Complex coacervation is a chemical form of microencapsulation. A complex coacervation solution is formed by dissolving a polymer, such as a gelling protein like gelatin, in water. This solution is then combined with the active ingredient. After a separation phase, the protein polymers build a protective wall around the active ingredient. Eventually, the protein's polymer chains cross-link, turning into a solid or a gel to form the microencapsulation membrane. However, there are limited food-grade cross-linking materials that can be used in this process, limiting its application in the food industry.

Our Solution: wowCAPS

The techniques mentioned above are some of the common forms of microencapsulation. Our company, GAT Food Essentials, has introduced another microencapsulation technology, branded under the name wowCAPS. It recently received the 2009 Frost & Sullivan European Functional Food & Beverage Microencapsulation Technology Innovation Award.

The technology is a multiple microencapsulation technology. Polymers are cross-linked in situ forming a suspension of water-in-oil-in-water, or WOW, which can contain active ingredients. The active ingredient can be added at either the oil or the water phase, depending on whether the ingredient is soluble in water or oil.,

We believe that this technology offers several important benefits to the functional foods and beverages industry. First of all, the technology can achieve a very small particle size (approximately 2 µm), lending particles the ability to be incorporated in a wide range of products, including ambient and chilled foods and beverages. The technology can also microencapsulate up to 99.9% of an active ingredient, and is compatible with a wide range of functional ingredients, including omega-3 oils, antioxidant extracts, and mineral salts. All functional-food ingredients microencapsulated using wowCAPS technology show the same characteristics in terms of handling, processing, and product stability, providing companies with formulation flexibility and allowing them to save on new-product development costs by keeping development phases to a minimum.

The microcapsules themselves are also water- and oil-soluble, and can therefore be added to wide range of food and beverage products-mainly, dairy products such as milk, yogurt, and cheese; baked goods, such as cereal bars, cookies, and bread; and meats, such as ham, cold cuts, and sausages.

The wowCAPS process also makes microcapsules very stable. Stability of the active ingredient is maintained during processing and over the entire shelf life of the food or beverage application. Active ingredients remain stable, from the time they are incorporated in a product until the end of the product's shelf life, without any occurrence of oxidation or degradation.

The technology offers controlled release of ingredients. The microencapsulation shell, which consists of cross-linked polymers, remains intact at pH levels above 3.0. Upon consumption of a product, the microcapsule particle walls will break fully when pH levels, such as those of gastric acid, reach approximately 1.5 to 2.0. This controlled release results in a high bioavailability of the active ingredient, and ensures customers that they will benefit from as much of the healthy ingredient as possible.

Finally, and importantly, wowCAPS uses only natural and GMO-free materials. This allows microencapsulated ingredients using wowCAPS the ability to be certified organic.

Looking Forward

The evolution of microencapsulation technologies to better handle functional-food ingredients is continuous. Following market trends and customer needs, development work is focusing on meeting evolving demands, such as those of organic food standards, as well as allowing the fortification of more-complicated and sensitive applications, such as infant-nutrition products.

Rebecca Albrecht works in the R&D department of GAT Food Essentials and is currently conducting a study on the stability of microencapsulated omega-3 fatty acids. Gregor Riss is product manager at GAT Food Essentials and assists its customers all over the world in developing functional-food concepts and products.