Influence of modified atmosphere packaging on quality, vitamin C and phenolic content of artichokes (Cynara scolymus L.)

Abstract

The influence of modified atmosphere packaging (MAP) on the visual quality and the content of phenolics and vitamin C in artichokes cv. Blanca de Tudela stored at 5 °C was studied in order to prolong shelf life. Six different films were used: perforated polypropylene (Control), polyvinylchloride (PVC), low density polyethylene (LDPE) and three microperforated polypropylene films (PP1, PP2 and PP3). The modified atmosphere (O2+CO2) reached at the steady state was 14.4 kPa+5.2 kPa for PVC, 7.7 kPa+9.8 kPa for LDPE, 8.6 kPa+15.3 kPa for PP1, 9.7 kPa+13.8 kPa for PP2 and 13.7 kPa+9.5 kPa for PP3. No gaseous modifications were obtained within the Control packages. Loss of water was the major cause of artichoke deterioration after 8 days of storage at 5 °C, and was minimised by MAP. Quality loss decreased after storage, particularly for Control artichokes, although all samples were considered acceptable. The vitamin C content of the internal bracts (edible part) was higher than that of the external bracts and decreased after storage by MAP, while for Control artichokes it remained as at harvest. On the other hand, a large phenolic content (896.1 mg 100g-1 fresh weight) was detected in the internal portion compared with the external bracts and this remained unchanged for Control artichokes after storage. However, a larger increase was observed in the internal bracts of artichokes by MAP, particularly for LDPE and PVC. Phenolic derivatives 1,5-dicaffeoylquinic (diCQA), 3,5-diCQA, 1,4-diCQA and 4,5-diCQA were the main compounds responsible for this increase.