الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
The importance of antioxidants in food preservation as well as their vital role for human health is well known. However, using many natural antioxidants in food and pharmaceutic industry is confined by their stability during storage and their solubility in different media. Therefore, two types of natural antioxidants, tocopherols and anthocyanins, were selected to enhance their stability. α-Tocopherol (vitamin E) is a fat-soluble antioxidant well distributed in vegetable oils and responsible for oil stabilization. Anthocyanins are class of flavonoids which are water-soluble and exhibit strong antioxidant activity in addition to giving many fruits and vegetables their characteristic red-violet colors. Tocopherols were used in the form of α-tocopherol (α-TQ) and α-tocopheryl acetate (α-TQA) while anthocyanins were used as strawberry extract. To enhance their stability, their complexes with natural hosts i.e. ß-cyclodextrin (ß-CD) and corn starch were prepared and characterized by spectroscopic analysis (UV-Vis and IR) and thermal analysis (TG, DTG and DSC). The stability of the tested antioxidants and their complexes were examined and compared against hydrogen peroxide, which is produced naturally in biological systems, in addition to visible light and UV radiation. Stability results showed that both ß-CD and starch complexes of both types of antioxidants were more stable than free antioxidants under all the examined conditions. In addition, major anthocyanins in strawberry extract were identified as pelargonidin-hexose and cyaniding-hexose; their products after exposure to light and UV radiation were also identified by LC-ESI-MS.