Influence of light exposure during storage on the content of sesquiterpene lactones and photosynthetic pigments in witloof chicory (Cichorium intybus L. var. foliosum Hegi)

Greening of witloof chicory is a major quality defect being commonly associated with increased bitterness. The aim of this study was to assess the effect of light exposure during storage on levels of bitter sesquiterpene lactones (SLs) and photosynthetic pigments in leaves and central axes of two cultivars of witloof chicory. For this purpose, witloof chicory packaged in consumer-sized polyamide bags was stored in the dark (8 degrees C) and under light exposure (8 degrees C, 4500 lux), respectively, over a period of 11 days. Throughout storage, O-2 and CO2 levels in the modified atmosphere were monitored. Levels of six individual SLs, chlorophyll derivatives and beta-carotene in leaves and central axes were assessed by HPLC-DAD-MSn and color measurements were carried out applying the CIE L*a*b* system. Light exposure during storage resulted in a higher respiration of the plant tissue as well as in a marked rise of photosynthetic pigments in the leaves rather than in the central axes. Furthermore, illumination during storage distinctly raised SL levels in the central axes, while SL levels in chicory leaves were less affected. (C) 2014 Elsevier Ltd. All rights reserved.