Molecules with special talents: cyclodextrins resemble donuts that are able to accommodate specific molecules and then selectively release them. This principle is finding application in particular for health-promoting ingredients. Cyclodextrins are able to hide the sometimes bitter taste of unctional ingredients, protect these sensitive substances and ensure that they are better absorbed by the body.

Vitamins keep living cells young: Linus Pauling, winner of the 1954 Nobel Prize in Chemistry, was so convinced of their efficacy that he consumed almost 18 grams of pure vitamin C a day. It’s debatable whether that’s why he lived to be over 90. One thing is certain, though: the body cannot function long without vitamins, minerals and trace elements. And scientists are discovering new health-promoting ingredients all the time that make the body resistant to environmental stress, prevent certain diseases or even slow the aging process.

Green tea, for example, is reputed to confer health benefits. Its tannins contain "catechins," compounds with antibacterial properties that are capable of neutralizing free-radicals. As well as being anti-inflammatory, catechins are thought to play a role in cancer prevention. But the catechins make green tea taste very bitter.

Taste is important – even for functional foods

Food companies are thus faced with a dilemma. On the one hand, they want to provide their products with an additional health-promoting benefit, which is why they fortify soft drinks, for example, with green tea extract. But, on the other hand, by adding this functionality, they are incorporating the bitter aftertaste. True, the product does contain the desired health promoter, but of course no consumer wants a thirst quencher that has a bitter taste.

One option is to mask the bitter catechin taste, for example, with more sugar. However, more sugar means more calories, which is not always acceptable. Another solution is to use additional flavours, but these weigh on costs and can impair the flavour profile.

The solution: a cyclodextrin wrapper

WACKER’s development team has devised another option: a wrapper made of cyclodextrins. These ring-shaped molecules, which are produced enzymatically from starch, are able to incorporate other molecules in their inner cavity. The bitter substance contained in green tea is bound in the cyclodextrin, so its taste is no longer perceived by the consumer.

The newly created laboratory for dietary supplements at WACKER’s largest site in Burghausen is concentrating on developing new product solutions for the beverage and dairy industries. At the top of the Food Laboratory’s agenda are analytical test methods, the optimization of taste and the stability of sensitive ingredients. The objective is to devise custom solutions with clients so as to enable and optimize the use of functional substances in their products.

Food labs focus on dietary supplements

Besides the newly established test laboratory in Burghausen, WACKER has a food laboratory in Adrian, Michigan which has been in operation since 2006. The developers’ focus is mainly on dietary supplements. These include all kinds of vitamin capsules and powder blends containing essential trace elements and health-promoting substances. Often, the challenge posed by these products lies in ensuring that the active ingredients are absorbed by the body. The substances in the product must therefore be bioavailable, as only then will they prove efficacious in the body. Whereas hydrophobic substances are poorly absorbed into the bloodstream, hydrophilic compounds are absorbed much more readily. This is where cyclodextrins come in, as they can give a substantial boost to the bioavailability of hydrophobic substances.

Coenzyme Q10 plays a key role in the body

One functional ingredient that is often employed in dietary supplements is coenzyme Q10. This vitamin-like molecule is present in every human cell, where it plays a central role of ensuring that the food we eat is converted efficiently into energy. But Coenzyme Q10 has very poor water solubility and thus has very little bioavailability. As a dietary supplement, though, it is very interesting because its concentration in a person’s body decreases with age. Eighty-year-olds have only half as much coenzyme Q10 as twenty-year-olds.

Dietary supplements are a proven way of keeping the stores of coenzyme Q10 well stocked – particularly in people who are engaged in heavy physical work, are under stress or are elderly.

Yet, it cannot be simply stirred into water and then drunk. Coenzyme Q10 would float on the surface like fatty cocoa powder and form insoluble lumps. Furthermore, only a fraction of the added coenzyme Q10 would be absorbed. Cyclodextrins can be used to increase its solubility and thus boost its bioavailability. The ring-shaped cyclodextrins have a hydrophobic ‘pocket’ and a hydrophilic shell, and look somewhat like a donut. Coenzyme Q10 tucks itself away inside this donut, creating a complex with the cyclodextrin. After being stirred into liquid, the coenzyme within the cyclodextrin forms a molecular dispersion which the body can absorb much more readily. Release of coenzyme Q10 within the body is a chemical equilibrium process in which the molecules gradually come ‘out of their shell’. In vitro and in vivo studies have shown that coenzyme Q10 uptake can be substantially improved if it is complexed with a cyclodextrin-coenzyme Q10 complex.

The complexation with cyclodextrins yields a free-flowing powder, containing at least 20 weight-percent of the functional active ingredient, which has high bioavailability. One of WACKER’s customers is US-based Tishcon Corporation. It is already successfully using this innovative packaging for coenzyme Q10 in its own line of dietary supplements and in products for private-label companies. For the first time, the complexation with cyclodextrins has provided the opportunity to offer powder-based coenzyme Q10 products which have the same high bioavailability as liquid formulations.

Cyclodextrins stabilize alpha-lipoic acid

Another useful property of cyclodextrins is their protective action. Cyclodextrins shield numerous functional compounds against various external influences (low pH, oxygen, and light) that could compromise their effectiveness. For example, they are highly adept at stabilizing alpha-lipoic acid, which is also used in dietary supplements and in sports nutrition. This substance acts as an efficient free-radical scavenger, neutralizing aggressive oxygen molecules which are formed by cell metabolism and which can damage the body.

What’s more, alpha-lipoic acid can regenerate other, spent antioxidants (vitamin C and vitamin E; coenzyme Q10), which is of interest for competitive athletes. In addition to protein drinks and energy bars, there are special powder mixtures available which are designed to replenish the depleted reserves of vitamins, minerals and antioxidants – including alpha-lipoic acid. This compound is not easily incorporated into powder products as it is very sensitive, especially to heat and the presence of certain minerals. Even in the dry state, it can polymerize, i.e., form long, chain-like structures. This chemical reaction causes the alpha-lipoic acid to lose its desired effect.

Again, cyclodextrins can act as a practical protective wrapper: embedded in the cyclodextrin, the sensitive molecule is safely tucked away inside the athlete’s special powdery dietary food. As soon as the cyclodextrin complex comes into contact with water, the alpha-lipoic acid emerges from its protective coat and is absorbed directly by the body – the free-radical scavenger enters the bloodstream unscathed. This protective solution was specifically developed by WACKER on behalf of AlzChem Trostberg GmbH, a German specialty chemicals company whose portfolio includes products for the food and sports nutrition field. The specialized cyclodextrin complex maximizes the product’s efficiency by ensuring that as much of the free-radical scavenger as possible remains effective in the powdered end product.

Customized research and development

All of these examples illustrate the new approach adopted by WACKER BIOSOLUTIONS, especially regarding the Nutrition and dietary supplements business team’s strategy, namely, the development and delivery of complete solutions tailored specifically to customers and their needs. Many small and medium sized suppliers of the food industry do not have their own R&D departments. This provides a point of entry for the company to use its expertise, experience and services to work together with customers on tailor-made solutions. For the future, the WACKER developers are targeting primarily three main effect platforms: masking of unpleasant tastes of ingredients, stabilization of sensitive ingredients and improving the bioavailability of functional ingredients.

For the food specialists at WACKER, cyclodextrins are a perfect example of how biotech know-how and chemical expertise successfully interact and may be used for developing customized solutions. The use of cyclodextrins in dietary supplements or as food additives is one of many innovative ways in which the WACKER Group will be seeking to assist the food industry in the future.

Wacker Chemie AG

Munich, Germany

www.wacker.com