Phenolic profiles and postharvest quality changes of fresh-cut radicchio (Cichorium intybus L.): nutrient value in fresh vs. stored leaves

The quality traits of two "Radicchio di Chioggia" hybrids (Corelli and Botticelli) processed as fresh-cut and stored in unsealed bags or in passive modified atmosphere for 25 days at 5 °C, were measured in two consecutive experiments. Moreover, on fresh and stored samples, a detailed structural characterization of the polyphenols of radicchio extracts extracted from fresh and stored radicchio samples was performed by HPLC and electrospray ionization multistage ion trap mass spectrometry (ESI-ITMSn). Twenty-one compounds were identified and quantified in Corelli extract, while nineteen ones were detected in Botticelli extract. Quercetin-7-O-glucoside-3-O-(6"-malonyl)-glucoside and isorahmnetin-7-O-glucuronide were found only in Corelli. Interestingly, the presence of dihydroflavonol glycosides in "Radicchio di Chioggia" is here reported for the first time. In the second experiment (performed on Botticelli), fresh-cut processing promoted a 2-fold increase in bioactive compounds, quantified in a significant amount (305 mg/100 g fresh weight) also in leaves scored unmarketable. Thus this hybrid, suited for fresh-cut processing, showed to be also an interesting and cheap source of antioxidant phenolics, when was no more acceptable. Although less suitable for fresh-cut processing, tThe Corelli fresh-cut radicchio, even if less suitable for fresh-cut processing, resulted a valuable hybrid for the fresh consumption and a source of polyphenols due to for their high content measured in fresh and stored leaves.