Bioavailability of the antioxidative Rosmarinus officinalis compound carnosic acid in eggs

Rosemary is one of the herb spices and it exhibits antioxidative activity. The phenolic diterpene carnosic acid is mainly responsible for these antioxidant effects in rosemary and rosemary extracts. A modified high-performance liquid chromatography method for the determination of carnosic acid in rosemary extract was established. The analysis can be accomplished under isocratic conditions using electrochemical detection. The effect of dietary rosemary extract on the bioavailability of the antioxidative compound carnosic acid in eggs was evaluated. Using this method carnosic acid could be detected in 20 ng/g of egg yolk. Results showed that carnosic acid is bioavailable in egg yolk but not in albumen.