The carotenoid, tocopherol and chlorophyll metabolic profiles and content of a selection of fruits and vegetables found commonly in the diet, have been determined using a rapid RP-HPLC technique with on-line PDA detection. Information gathered from the screening of secondary plant metabolites is vital for the accurate determination of the dietary intake of these micro-nutrients, and in the development of comprehensive food tables. Determination of basal levels is also necessary for the rational engineering of health-promoting phytochemicals in food crops. In addition this approach can also be applied to the routine screening of products to determine metabolic differences between varieties and cultivars, as well as between genetically modified and the corresponding non-genetically modified tissue.