Determination of free and bound carotenoids in paprika (Capsicum annuum L.) by LC/MS

A protocol for extraction and chromatographic separation with a C30-reversed-phase column for analysis of non-saponified lipid extracts of paprika fruits by LC/MS has been developed. Using this procedure it was possible to identify the main mono- and diesterified derivatives of capsanthin, capsorubin, beta-cryptoxanthin, and zeaxanthin naturally occuring in red peppers. LC/MS analyses proved that xanthophylls of red peppers were exclusively acvlated with saturated C12, C14, and C16 fatty acids whereas unsaturated as well as C18 fatty acids were generally absent. However, saponification experiments on paprika lipid extracts showed that approximately 75% of the total fatty acids of red peppers are C18 fatty acids. These findings can only be explained by selective esterification of xanthophylls during maturation of red peppers. In contrast, direct extracts of green peppers comprised only free carotenoids, while the fatty acid distributions of green and red peppers did not differ significantly.