Comparing the physiological changes in apples and pears during shelf-life measured by fluorescence imaging

Abstract

The physiological state of plants during their development can be determined using chlorophyll fluorescence, induced after excitation with UV-, blue-, green-, orange- or red-light. During fruit ripening and senescence, two major phenomena affect the level of chlorophyll fluorescence emission: (i) a loss of photosynthetic competence per unit chlorophyll leading to reduced PSII activity and (ii) a decrease in chlorophyll content. In this paper, chlorophyll fluorescence characteristics of some physiological changes in 'Conference' pears (Pyrus communis L.) and 'Jonagold' apples (Malus domestica Borkh.) during a shelf-life experiment are studied using the PEA (Plant Efficiency Analyser) and a custom build fluorescence imaging system (FIS). The apples and pears were bought in a local store and were followed during several days in order to detect physiological changes during this period. The results show that chlorophyll fluorescence imaging is more reliable compared to a point measuring technique such as the PEA and can be used to predict the shelf-life quality of 'Conference' pears and 'Jonagold' apples.