Abstract: Safflower (Carthamus tinctorius L.) belongs to composite family. Its florets contain edible carthamin and safflower yellow dyes. The pigments are very useful for dying foods and cosmetics. The natural pigments also have medicinal properties. In this research, external factors suspecting to influence the chemical nature of carthamin and safflower yellow in aqueous media were studied. Dried florets were powdered and used for the extraction of carthamin which was obtainable through alkaline extraction, acidification and cellulose adsorption. Also, dried safflower powder was used for extraction of water soluble yellow pigment. Aqueous solutions of the pigments were exposed to some external factors such as temperature (10, 30, 50 and 70°C), pH (below 2 and above 7), light (400 Lux and UV). The results showed at higher temperature carthamin was more readily decomposed, but safflower yellow isn’t affected so much by the temperature. Occurring above and below the pH range in which carthamin is most stable (pH 3-5.5), increased degradation of the pigment. The pigments in aqueous solution were exposed to dark, visible and ultraviolet light. Loss of safflower yellow coloration increased. These results were studied spectrophotometerically to check patterns of stability of the pigments. Comparing the pigments indicates safflower yellow is more stable than carthamin in temperature and pH treatment, but carthamin is more stable than safflower yellow in light treatment. Most synthetic pigments have carcinogenic properties, whereas natural pigments have biological value and belong to natural components of food products.
N. Fatahi , . Carapetian and R. Heidari , 2009. Comparing Stability of Carthamin and Safflower Yellow Pigments at PH, Temperature and Light, from Safflower (Carthamus tinctorius L.) Florets. Research Journal of Biological Sciences, 4: 250-253.