Effects of cultivation year and growing location on the phenolic profile of differently coloured carrot cultivars

Abstract

Carrots (Daucus carota L.) are economically and nutritionally important crops that, apart from carotenoids, contain numerous phenolic compounds which are assumed to exert health beneficial effects. The total phenolic contents of fruits and vegetables are known to depend on cultivar and growing conditions; however, studies examining the variability of a collection of carrots comprising differently coloured cultivars are rare. Therefore, the objective of the present study was to investigate the phenolic compounds of ten differently coloured carrot cultivars considering the effects of three cultivation years at two growing locations.
Although total phenolic contents varied in a wide range, both purple cultivars ‘Anthonina’ and ‘Deep Purple’ significantly exceeded those of yellow, orange, red, and uncoloured cultivars (P ≤ 0.05) with amounts from 4,113 to 11,737 mg [kg dry matter (DM)]^-1. In contrast to the purple roots, the other generally were characterised by far lower polyphenol contents ranging from 33 to 1,369 mg (kg DM)^-1. Interestingly, the values did not considerably vary within these cultivars. In the present study, contrary to cultivar specific effects, the infl uence of growing location was found to be rather weak, supposedly due to similar climatic conditions at both locations. Similarly, variation of phenolic contents from year-to-year was less pronounced. In conclusion, the selection of breeding material was found to be of utmost importance regarding the expression of polyphenols in differently coloured carrots.