Abstract
This study investigated the changes in carbohydrate content and activities of invertase, sucrose synthase and sucrose phosphate synthase in two broccoli cultivar (Brassica oleracea L. Cvs. ‘Hartland’ and ‘Sairin’) stored at 5°C. Respiration rate rapidly declined after 1 day of storage and gradually decreased at the end of the storage period. Color did not change significantly at the end of the storage period. In both cultivars and portions, the invertase activity increased gradually at the end of the storage time. The acid invertase in cell wall-bound fraction (CWBF) showed a higher activity than that in soluble fraction (SF). Again, the branchlets showed a significantly higher invertase activity than that of florets. In both cultivars, sucrose synthase (SS) activity gradually increased in the florets with some fluctuations in the branchlets at the end of the storage time. Sucrose phosphate synthase activity (SPS) activity did not change markedly in any portion of the two cultivars at the end of the storage period. Sucrose content gradually decreased in both portions of the two cultivars with time. It was negatively correlated with the acid invertase and SS activities in both portions accounting well for the relation between the substrate and the activity. Fructose and glucose content were higher than sucrose in the florets as well as branchlets in both cultivars.