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

Abstract

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 25days at 5°C, were measured in two consecutive experiments. Moreover, a detailed structural characterization of polyphenols 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, and 19 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 (305mg/100g fresh weight) and in leaves that had been considered unmarketable. Thus this hybrid, suitable for fresh-cut processing, has been shown to be an interesting and inexpensive source of antioxidant phenolics even in leaves considered as unmarketable. Although less suitable for fresh-cut processing, Corelli fresh-cut radicchio can be considered a valuable hybrid for fresh consumption and a source of polyphenols because of the high content of these compounds in both the fresh and stored leaves.