The chemical composition of some garden Dahlia tubers

Abstract

PurposeDahlia is an ornamental plant originating from Mexico where it is considered as the National flower. The purpose of this paper is to investigate tubers from yellow, white and red‐flowered cultivars of the common garden Dahlia (D. pinnata) for their chemical composition.Design/methodology/approachThe composition of minerals was determined using Atomic Absorption Spectrometry (AAS), whereas vitamins were analyzed by High‐Performance Liquid Chromatography (HPLC).FindingsCarbohydrates represented the major constituent in Dahlia tubers, followed by fibre and protein. Tubers of the yellow‐flowered cultivar “HGH” contained the highest amount of carbohydrates, while tubers of the white‐flowered cultivar “BJ” and those of the red‐flowered cultivar “XM” abounded in fibre and protein, respectively. In addition, Dahlia tubers exhibited varying concentrations of minerals, among which potassium, calcium, magnesium, phosphorus, zinc and chromium were predominant. Tubers of the white‐flowered cultivar “LB” contained the highest amounts of magnesium and phosphorus. Moreover, tubers of the red‐flowered cultivar “MLH” showed the highest contents of potassium and chromium, whereas those of the red‐flowered cultivar “XM” were rich in calcium and zinc. Furthermore, Dahlia tubers were found to contain water and fat soluble vitamins, among which vitamins B2, B6, B7 and E were the most abundant. Tubers of the white‐flowered cultivar “BJ” exhibited the highest contents of water soluble vitamins, whereas those of the white‐flowered cultivar “LB” abounded in fat soluble vitamins.Originality/valueDespite the considerable variability observed among cultivars, Dahlia might be utilized as an alternative food resource for human nutrition.