Analysis of sugars and organic acids in ripening mango fruits (Mangifera indica L. var Keitt) by high performance liquid chromatography

The sugars and organic acids present in the pulp of Keitt mangoes at various stages of ripeness were analysed by h.p.l.c. Ripening was associated with a loss in firmness, peel chlorophyll and pulp acidity, with increasing soluble solids and total sugars. The major sugars were identified as glucose, fructose and sucrose. All three increased during ripening; sucrose was found to be in the greatest concentration throughout, with fructose the predominant reducing sugar. Acidity loss was shown by decreasing titratable acidity and increasing pH values. Citric and malic acids were found to be the major organic acids. A large decrease in citric acid and a small reduction in malic acid were responsible for the loss of acidity. Tartaric, ascorbic, oxalic and α-ketoglutaric acids were also shown to be present at low concentrations.