CHANGES IN CAROTENOID ESTERIFICATION DURING THE FRUIT RIPENING OF CAPSICUM-ANNUUM CV BOLA

During fruit ripening of pepper (Capsicum annuum), de novo biosynthesi s and esterification of carotenoids occur simultaneously. From the ver y first stages of ripening the totally esterified fraction of xanthoph ylls is the majority (around 50%). During the ripening process, free x anthophylls decrease in proportion to the rest and at the same time th e partial esterified xanthophylls increase in proportion at the expens e of the free fraction and simultaneously a portion of the partial est erified xanthophylls are transformed in totally esterified xanthophyll s. In the fully ripe fruit the percentages of the free carotenoid pigm ents and the partially and totally esterified forms of these are 21.3% , 35.6%, and 43.1%, respectively. The fatty acids esterifying yellow x anthophylls are chiefly linoleic (18:2DELTA9,12), Myristic (14:0), and palmitic (16:0), whereas in red xanthophylls they are lauric (12:0), myristic (14:0), and palmitic (16:0). This fact helps to explain the g reater stability of the red xanthophylls compared to the yellow ones, because of the number of double bonds in the fatty acid chains.