Carotenoid pigments of Dioscorea cayenensis

Abstract

S U M M A R YThe yellow flesh of Dwscorea cayenensis, a principal yam of Africa, was found to contain xanthophyll esters as the principal pigments. These included neoxanthin, violaxanthin and auroxanthin. In addition ,&carotene, or pro-vitamin A was found in small quantities. Measurements show that D. cayenemis is a fair source of this nutrient.

Pigments in Vegetables

“…This fact was observed for the first time in the cherry tomato (Laval- Martin et al, 1975). During the lag phase that precedes maturation, the granal system of the chloroplasts disintegrates, and chlorophylls and part of the chloroplast carotenoids disappear (Laval-Martin, 1974).…”

“…The outer pericarp has the highest carotenoid concentration, and locular contents have the highest carotene content (Bauerfeind, 1981). In the cherry tomato the distribution of the pigments is different in the inner "pulp" and the outer "flesh" (Laval- Martin et al, 1975). Whereas {j-carotene is equally distributed, lycopene predominates in the flesh in which the total carotenoid content is sixfold higher than in the pulp.…”

Carotenoid profiling of yams: Clarity, comparisons and diversity

“…The extraction method utilised up to 20-fold less raw material and less than half the solvent of the commonly applied modified HarvestPlus approach (Champagne et al, 2010;Ferede et al, 2010;Ukom et al, 2014), whilst attaining profiles which matched some of those previously recorded, with many xanthophyll esters, e.g., D. alata (Champagne et al, 2010), D. bulbifera (Martin et al, 1974) and D. cayennensis (Martin & Ruberte, 1975) and stereoisomers present. The scaled-down extraction allowed increased throughput with easier sample handling and, consequently, the relatively long run-time of the HPLC was the limiting factor for the speed of screening.…”

“…This reduction is commonly attributed to reduced β-carotene content (Martin & Ruberte, 1975;Martin & Sadik, 1977). In this study, D. rotundata typically had more lutein and less xanthophyll esters than D. cayennensis.…”

“…D. cayennensis is reported to have higher carotenoid content (Bhattacharjee et al, 2011;Gedil & Sartie, 2010;Lebot, 2008), whilst D. rotundata is preferred by farmers and consumers. A few studies have showed that β-carotene is the major carotenoid of D. cayennensis (Ukom, Ojimelukwe, & Alamu, 2016;Ukom, Ojimelukwe, Ezeama, Ortiz, & Aragon, 2014), yet, other reports show β-carotene is of minor presence in the species (Champagne et al, 2010) and that the major carotenoids are xanthophyll esters (Martin & Ruberte, 1975). Recent work has shown varieties of D. dumetorum with estimated vitamin A activity at levels similar to that of enhanced cassava genotypes (Ferede, Maziya-Dixon, Alamu, & Asiedu, 2010).…”