Postharvest senescence of florets from primary and secondary broccoli inflorescences

Abstract

The shelf-life of fresh-cut vegetables may be markedly affected by the type and quality of the raw materials. In this work we evaluated the influence of the type of inflorescence used for processing (primary and lateral) on the postharvest senescence of refrigerated fresh-cut broccoli. Florets from primary and lateral heads were cut and washed with chlorinated water, rapidly cooled to 4°C, packed in plastic trays covered with perforated PVC and stored at 4°C for 0, 14 or 21d. During storage we evaluated floret deterioration, respiration rate, weight loss, color, chlorophyll content, sugars (glucose, fructose and sucrose), antioxidant capacity against ABTS+ and DPPH radicals, ascorbic acid and Folin-Ciocalteu-reacting substances. Florets from lateral inflorescences were more perishable than fresh-cut broccoli obtained from primary heads. Terminal florets retained higher chlorophyll levels and showed delayed yellowing. Already at harvest primary-broccoli showed lower respiration rate. Florets form terminal heads showed lower weight and sugar loss during storage and maintained higher visual quality throughout the storage period at 4°C. The inflorescence type also had large impact in the initial level of antioxidants as well as in their metabolism during storage. This information may be useful for vegetable processors.