Influence of pre-cutting operations on quality of fresh-cut artichokes (Cynara scolymus L.): Effect of harvest dates

Abstract

The effect of harvest date on post-cutting quality of two cultivars (‘Violetto foggiano’, and ‘Catanese’) of artichokes (Cynara cardunculus L. subsp. scolymus (L.) Hayek) was studied. Artichoke heads were harvested from December 2009 to May 2010 for ‘Violetto foggiano’ (7 harvest dates), and from January to April 2010, for‘Catanese’ (4 harvest dates) from a commercial orchard in the Apulia Region, always from the same 20 randomly-chosen and labeled plants (for each cultivar). Freshly harvested artichoke heads were trimmed, cut into quarters, then stored in a humidified air flow at 5°C. Initially, and after 2, 5 and 7 days of storage, quality parameters were analyzed, including total phenol content, antioxidant activity, color attributes (outer bract surface, cut-bract surface, and cut receptacle) and visual appearance. Global color variations (ΔE*), for receptacle, cut surfaces and outer bracts, were calculated, in order to compare samples of different initial color and to evaluate variation in terms of browning. Artichokes ‘Catanese’ harvested in February showed the lowest ΔE* on cut surfaces after 7 days of storage which then increased with the proceeding of the season. Also for ‘Violetto foggiano’ after 7 days of storage, samples harvested in February showed lowest values of ΔE* on cut surfaces (bracts and receptacle), if compared to other harvesting dates. Visual quality of fresh-cut quarters decreased with the progress of the season, and for ‘Violetto foggiano’, with the decrease of the antioxidant activity. Total phenolic content and antioxidant activity were different among harvest dates for both cultivars studied, and for ‘Violetto foggiano’ showed a significant polynomial trend, denoting 2 phases of antioxidant accumulation from December to February and then from middle of March to May. The natural decline of plants at the end of production may be the reason of the poor quality of cut-artichokes in the last sampling date, and in general, considering the average temperatures at harvest, quality of fresh-cut artichokes could be positively affected by the lowest temperatures occurring in February.