Validation of a fluorometer sensor for characterization of olive varieties and evaluation of fruit ripeness index with non-destructive measurement: preliminary results

Abstract

Traditionally, the criteria for deciding the optimum time to harvest olives are related to the change in color of the fruit. Olive ripeness is caused by the degradation of chlorophyll together with the synthesis of other pigments such as anthocyanins. The oil content components have also been another indicator for taking the decision to harvest olives. The objective of this work is to obtain a decision support system based on a preliminary validation of the MULTIPLEX RESEARCH™, which is a hand-held multi-parameter optical sensor based on non-destructive leaf and fruit autofluorescence measurements. The MULTIPLEX RESEARCH™ sensor provides accurate and complete information on the physiological state of the plant. The equipment generates several indices related to the quantity of flavonoids, anthocyanins, chlorophyll and other fluorescence indices, among them those related to nitrogen nutrition (NBI®) and fruit quality (FERARI®). This instrument uses the fluorescence of plants to measure the polyphenols and chlorophyll compounds in vivo. In this preliminary study, it was possible to define significant differences between the profiles defined by the set of more than 30 indices generated in the analysis of fruits of 12 olive varieties, considering two ripening stages in each.