As a water-soluble fiber in beverages, dairy products or breakfast cereals, alpha-cyclodextrin, for example, has a demonstrably positive effect on an individual’s glycemic index, as confirmed by the European Food Safety Authority (EFSA). Bioengineered from starch, these ring-shaped molecules are furthermore well suited for increasing the bioavailability of hydrophobic food supplements, such as curcumin. Cyclodextrins are purely vegetarian-grade, non-allergenic and are produced entirely from re-newable raw materials.
While nutritionists recommend a daily intake of 25 to 30 grams of dietary fiber, most people in western industrial countries eat much less fiber. Unfortunately, low solubility and potential discoloration of the final product frequently discourage the use of fiber additives in bever-ages and food.
One solution is alpha-cyclodextrin, a water-soluble source of fiber with a very low viscosity that remains stable even at high temperatures and low pH. Irrespective of the pH, no undesirable browning reactions or discoloration occur – even in complex food systems. And because it dissolves to form a clear solution, alpha-cyclodextrin can also be used in beverages. Additionally, alpha-cyclodextrin is scientifically proven to regulate blood sugar after high-starch meals – an effect that has recently been confirmed by the European Food Safety Authority (EFSA). Other studies show a positive effect on blood lipids.
This makes alpha-cyclodextrin particularly suitable as a beverage additive – and it also works well in other traditional applications for fiber, such as dairy products, baked goods and breakfast cereals. Alpha-Cyclodextrin is a natural degradation product of starch, for ex-ample, corn or potato starch. WACKER produces alpha-cyclodextrin enzymatically from renewable raw materials.
In addition to their use as water-soluble fiber, cyclodextrins also do an excellent job of increasing the bioavailability of ingredients such as curcumin, which is hydrophobic, i.e. not readily soluble in water. Cur-cumin, the biologically active compound in turmeric, is a powerful antioxidant that has been shown to exhibit anti-inflammatory, antibacterial and hypoallergenic properties. Because curcumin is very hydrophobic, however, it is not readily absorbed in the human bloodstream. Curcumin’s use in nutritional supplements has often been limited, as a result.
This is where cyclodextrin technology comes into play. While these ring-shaped molecules have a hydrophilic shell, the hydrophobic cavity inside the ring allows them to accommodate other hydrophobic substances. Lipophilic curcumin, in other words, can slip inside the cyclodextrin ring. The hydrophilic surface of the resulting complex increases bioavailability and, as such, makes curcumin more soluble within the human body.
The effect has been demonstrated experimentally: solubility of the cyclodextrin-curcumin complex was determined in a simulated digestive fluid. Subsequently, CaCo-2 cells (a line of human intestinal cells) were used to examine absorption. The study showed that the cyclodextrin-curcumin complex dissolved five times more readily in the synthetic digestive fluid than commercially available curcumin nutritional supplements and pure curcumin extract. At the same time, absorption efficiency in human CaCo-2 cells increased by a factor of ten.
As this demonstrates, complexing compounds such as curcumin with cyclodextrins significantly improves the solubility of hydrophobic substances, and thus their bioavailability. Because they are free-flowing powders, cyclodextrin-based formulations are particularly suitable for use in dry or powdered nutritional supplements, such as tablets, capsules and power bars. Their ability to disperse readily in aqueous systems also enables the use of these powders in beverages.
