Harvest Season and Genotype Affect Head Quality and Shelf-Life of Ready-to-Use Broccoli

Abstract

Pre-harvest climatic conditions and genotype may have important effects on head quality and post-harvest performance of fresh-cut broccoli. The present work evaluates the effect of the growing cycle (summer–autumn (SA), winter (W), winter–spring (WS), and spring (S)) and genotype on qualitative (dry matter, concentration of chlorophylls, carotenoids, and color) and antioxidative (ascorbic acid, dehydroascorbic acid, total phenol concentrations, and antioxidant capacity) traits of broccoli heads and minimally processed florets. The WS raw product showed the best color indices (L* = 38.6, C* = 9.3 and h° = 123.8) as well as the highest chlorophyll (0.23 µg mg−1 fresh weight) but the lowest total phenol concentration (5.5 µg mg−1 dry weight - DW), whereas the ascorbic acid level (2.3 µg mg−1 DW) was comparable to or lower than that the other growing cycles. The WS florets confirmed their best visual quality, even showing an improved total phenol level after 14 days of cold storage. The climatic conditions experienced by broccoli plants grown in SA, W, and S periods were stressful as they resulted in a slight reduction in the visual quality of the heads, though only the SA florets showed a distinctive decay during storage. The lower post-harvest performance of SA grown broccoli was confirmed in all the tested cultivars, despite ‘Naxos’ seeming more tolerant. On the contrary, the greatest content of ascorbic acid (3.2 µg mg−1 DW) in the W heads and of phenols (11.1 µg mg−1 DW) in S heads was maintained during storage, thus preserving floret color.