THE EFFECT OF PREHARVEST PRUNING ON THE QUALITY OF CASSAVA STARCH

Two cassava cultivars CMC 40 and MPer 245 were grown at the Centro Int ernacional de Agricultura Tropicale (CIAT) in Colombia. Specimens were pruned by the removal of aerial growth 4 weeks prior to harvest and s tarch granules were isolated from the roots of pruned and control plan ts after harvest. The glassiness and hardness of cooked roots from the pruned plants showed an increase of 60-70% and 40-60% respectively co mpared with the controls, Although there was some reduction in the siz e of the starch granules derived from the pruned roots as compared wit h the control, pruning had negligible effects upon X-ray crystallinity , amylose/amylopectin contents, the elution patterns of the isoamylase debranched starch, the susceptibility of the granules to enzyme diges tion, their swelling power and solubility, the temperature and enthalp y of gelatinisation and their behaviour in the Rapid Visco Analyser. M inor differences were observed when pruned and control samples were ex amined in the Brabender amylograph.