Extraction and characterization of some natural plant pigments

Abstract

Antioxidant activities, total polyphenols and flavonoids, and antimicrobial effects in some plant pigments were determined in order to use these natural materials for cosmetics. The DPPH (1,1-diphenyl-2-picryl hydrazyl radical scavenging activity, % of control at maximum plants extract concentrations of 2500mg/L) in the thirteen natural plant pigments (black rice, purple sweet potato, yellow bitter melon, yellow paprika, red cabbage, yellow gardenia, blue gardenia, Chinese foxglove, mulberry leave, onion peel, grape peel, mulberry and red beet) ranged from 88.9% for red cabbage to 18.0% for blue gardenia. The highest total polyphenol content (404.2μg/ml) was measured in the onion peel pigment, and the lowest was in Chinese foxglove pigment (11.4μg/ml). The red cabbage had the highest total flavonoid amount which was 95.5μg/ml. The antimicrobial activities of the natural plant pigments were evaluated using the agar diffusion method. Most of the natural pigments for Bacillus subtilis, Micrococcus luteus, Escherichia coli, and Vibrio parahaemolyticus showed the clear zone formation of growth inhibition. Purple sweet potato, mulberry, mulberry leaf, grape peel, and blue gardenia showed high antimicrobial activities. These findings suggest that the pigments derived from natural plants had high biological activities, and exhibited different properties depending on each kind of pigments. Therefore these plant resources, having active functional components, can be used as excellent materials for natural cosmetics and food supplements.