Use of algal carotenoids as food colourants

Abstract

CHAPTER 1: General Introduction Carotenoids: Carotenoids are yellow or red colour pigments, which are widely distributed in plants and animals. Since the carbon skeleton of these compounds has a poly isoprene structure, they may be regarded as tetraterpenes. A food colourant, as defined by regulation, is any dye, pigment, or other substance that can impart colour to a food. Colour additives are important components of many products, making them attractive, appealing, appetizing, and informative. Choice of natural source for food colourant: To produce a food colourant we chose carotenoid as the source. The choice of carotenoids as the source for food colourant was not only due to their easy availability but also for the reason that carotenoids are considered to be one of the most potent nutritious pigments available in nature. The role of carotenoids as pro-vitamin A and in photosynthesis is known to all. Efforts are going on to explain and understand the role of carotenoids in human bodies. for choosing algae as a source of carotenoids: Good source of carotenoids: There are many good algal source for carotenoids e.g.. Dunaliella salina is a good source of B-carotene, while Haematococcus phrvialis is a good source of astaxanthin. Abundantly found in nature: There are many species of algae are widely available in the ponds, walls, barks and leaves. So, during our work we did not face any difficulty for the source. Easily collectable and easy to preserve: During the sunny days the algal species that we have studied float over the water surface of the ponds. So, they can be easily collected and preserved. CHAPTER 2: Materials and methods Extraction of total carotenoid: Carotenoids are organic solvent soluble pigments. Removal of chlorophylls from the algal extract was carried out by hydrolysis (in presence of alkali). Saponification of carotenoids: The algal extract was evaporated to dryness and dissolved in 10% KOH in methanol. The solution was heated at 600C for one hour. The reaction mixture was kept overnight at...