Use of Chlorophyll Fluorescence in Postharvest Quality Assessments of Fruits and Vegetables

Abstract

Chlorophyll fluorescence was initially developed as a tool for studying photosynthesis. The basis for this analysis is that changes in membranes or membrane-bound constituents of the chloroplast lead to changes in the fluorescence emission characteristics (Rosenqvist and van Kooten, 2002). In postharvest physiological studies, it has been determined that chloroplasts are one of the most sensitive membrane systems, similar in sensitivity to mitochondrial membranes (Toivonen, 1992). Thus, chlorophyll fluorescence changes can be potentially the most sensitive measure of membrane changes or perturbations in the plant cell. This fact permits postharvest researchers to gain useful information on early responses to postharvest stress in chloroplast-containing fruits and vegetables (DeEll et ah, 1999). A wide range of fruits and vegetables have shown chlorophyll fluorescence changes that were useful for prediction of stress response, including those that may not have been thought to contain significant amounts of chlorophyll, such as mature apples.