Content and Accumulation of Oxalic Acid in Edible Species of Xanthosoma.

Abstract

A study was conducted to determine the content and accumulation of oxalic acid in tissues of three edible species of the genus Xanthosoma: X. caracu, X. atrovirens and X. violaceum. Oxalic acid determinations were performed by atomic absorption spectrophotometry. Significant differences were found among the species and tissues studied. Oxalate content was higher in leaf blade and petiole tissues and lower in the pulp of the cormels or rhizomes. Oxalate content in the rhizomes was lowest in X. violaceum and highest in X. caracu. Accumulation in different tissues was progressive and simultaneous with tissue development. No evidence of acid translocation was detected. Postharvest storage of rhizomes resulted in progressive reduction in oxalate content. In all samples analyzed throughout the study the oxalate content of cormels never exceeded 3% of their dry weight.