HPLC Analysis and Determination of Carotenoid Pigments in Commercially Available Plant Extracts

Abstract

Carotenoids are a class of natural pigments, familiar to all through the orange-red colours, which are added to many manufactured foods in the forms of natural extracts or as pure chmically syntesided compounds in order to give the desired colouring properties. Recent evidence has correlated a diet rich in certain carotenoids with an increased protection against cardiovascular diseases or even certain types of cancer. In addition, on going research examines potential protective effects of these natural compounds in food systems e.g. oils and food emulsions. In order to understand and optimise the activity of the natural extracts when used in vitro or in vivo , it is really important first to to identify those active coumpounds that account for any any dietary and functional role. This paper focuses on the HPLC analysis of certain plant extracts aiming at the quantification and identification of the present natural carotenoid pigments. Saponification prior to HPLC Analysis was found to be successful in order to remove unwanted lipids and esters and thereby facilitate the idientification of main carotenoid pigments in the natural extracts. By use of UV spectroscopy, the total carotenoid content of each natural extract was also roughly estimated based on their extinction coefficient at the λmax of the main carotenoid pigment following dilution at the appropriate solvent. The identification and quantification of carotenoids in plant extract is considerd as essential in the further developmnt and optimisation of their functional uses as additives and dietary supplements.