What are Carotenoids?

Carotenoids are the class of hydrocarbons and there oxygenated derivatives (xanthophylls), along with chlorophyll, wide spread in nature and important pigments in living organisms. These richly colored molecules are the sources of the yellow, orange and red color of many plants. More than 600 naturally occurring pigments are synthesized by plants, algae and photosynthetic bacteria. They are present in most organisms including humans but can be synthesized by plants and microorganisms only. No animal is liable to synthesized carotenoids and they obtain it from food they consume. Some carotenoids may be slightly altered by oxidative metabolism during digestion and absorption. Animals differ greatly in the way that carotenoids from their diet accumulate in their tissues, especially in adipose tissue. The reason for these differences is not understood.