Anti-oxidation, Stabilization, and Improvement of Bioavailability

Many vitamins, fatty acids, pigments, and various other physiologically active substances are unstable and easily destroyed by heat, light (UV radiation), or acids, or 

Since vitamins are unstable and easily deteriorate, it is necessary to devise a formulation that will stabilize them. One effective method of achieving this is the use of various CyD inclusion complexes. In particular, y-CyD is becoming popular for the purposes of making liposoluble vitamins soluble in water, powdering them, or stabilizing them and increasing their bioavailability. 

Even the liposoluble vitamin E (tocopherol), which is unstable under sunlight, UV light, or heat, can be stabilized with y-CyD. When a mixture of tocopherol and starch was kept at 45 °C, 60% of its activity was lost in 17 weeks. But under the same conditions, y-CyD-included tocopherol lost only 20% of its activity. 

It is known that when vitamin C is mixed with anthocyanin as an antioxidant, the two substances form a condensation product. If vitamin C is present in various functional health foods, this quality deterioration is a problem. Furthermore, since vitamin C is highly soluble in water, it is impossible to stabilize it by CyD inclusion. However, a method of stabilizing vitamin C has been developed in which the antioxidant is included in a CyD to keep it remote from the vitamin C. In such cases, depending on the type of anthocyanin, either yS- or y-CyD is more effective. 

Unsaturated fatty acids such as DHA (mentioned earlier), eicosapentaenoic (EPA), arachidonic, y-linolenic and linoleic acids, and their alkali metal salts or esters are unstable, since air oxidation easily occurs at the double-bond site. Hence, plant and fish oils, which contain many triglycerides with a high proportion of unsaturated fatty acids, are easily oxidized, resulting in loss of stability in storage. It was considered difficult to stabilize triglycerides with CyDs since triglycerides are large molecules, but the use of y-CyD has allowed plant and fish oils to be stabilized [22]. 

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