The purpose of this graduation thesis was to determine total phenolic content, total flavonoid content and individual groups of flavonoids, and to determine the antioxidative potential (AOP) of bee pollen. The extracts of phenolic compounds were prepared by the solvent extraction with 96 % and 60 % ethanol. AOP was determined with the DPPH∙ radical scavenging method and the method of bleaching β-carotene which is based on the ability to inhibit lipid oxidation in the emulsion. In fresh bee pollen where extraction with 96 % ethanol was used we determined the total phenolic content of 6-13 mg gallic acid/g of dry matter and total flavonoid content of 5-13 of rutin/g of dry matter. The extracts obtained with 96 % ethanol, contained less total phenolic compounds and more total flavonoids than the extracts obtained with 60 % ethanol. During storage of bee pollen in the refrigerator, the content of phenolic compounds remained unchanged, the content of total flavonoids decreased. During drying the content of phenolic compounds decreased, especially flavonoids. One of the samples showed AOP, which was comparable to AOP of gallic acid, other samples showed lower DPPH∙ scavenging activity. Extracts prepared with 96 % ethanol were more efficient in emulsion than those prepared with 60 % ethanol. In emulsion the extracts showed efficacy comparable to the synthetic antioxidant butylated hydroxytoluene.
|
