Explain about Chlorophylls
Chlorophylls are used as colourants in a range of foodstuffs and both natural chlorophyll (containing magnesium as the central metal ion) and 'copper chlorophylls' (copper substituted for magnesium) are available. Both chlorophyll and copper chlorophyll are manufactured in fat soluble and water soluble forms by selective retention or hydrolysis of the phytol side chain. Apart from these three plant pigments, there are others such as red beet extract (betanin), cochineal, turmeric extract and others which have found use in food. As alternates to the above, there has been a search among the plant, animal and microbial kingdoms for pigments which are stable under conditions prevailing in foods (i.e., pH of 2 to 8; temperature of -20 to 110°C; presence of additives and preservatives).
Another approach has been to prevent the colour loss from foods. Both chemical and physical methods have been used to prevent destruction of natural colours in foodstuffs. As a means to achieve the desirable attributes of natural colours, it has been shown that biotechnological approaches appear to hold a lot of promise in the application of natural colours in foods. What are the sources of natural colourants? The next section details the sources of natural colourant.