Juicing Alters Oxalates Contents in Commonly Consumed Leafy Vegetables in South West Nigeria

Abstract

Oxalic acid is present in most vegetables in varying quantity; its salts are formed as insoluble complexes at physiological pH with divalent cations, minerals and trace elements. The crystals of oxalates are associated with different pathological conditions including kidney stones. Sixteen vegetables obtained from four major markets in South West Nigeria were thoroughly mixed, grouped into two samples (fresh vegetables and juice extract) and four replicates for each sample were analysed. Oxalates content was analysed using standard laboratory methods. Oxalates content in fresh vegetables group vary; Amaranthus viridis has the highest and it is significantly (p 0.05) different from Basella rubra, Amygdalina vernonia and Piper guineesis. Effect of juicing was notably significant in most of the vegetable when compared with their corresponding fresh vegetables. Telfairia occidentalis juice extracts had significantly (p<0.05) higher amount of oxalates than other juice samples, Crassocephalum rubens displayed the highest percentage increase compared with the corresponding fresh vegetable followed by Manihot esculenta while decrease was observed in three out the sixteen of the vegetables investigated and the highest percentage decrease was recorded in Talinum triangulare. The increased oxalate content observed in most of the vegetables analysed suggests the probable complications that may be associated with intake of certain vegetable juice. Hence, juicing must be used with caution. Thus, intake of such juice must be done with caution in people susceptible to oxalates intoxication.