‘In Situ’ olive ripening monitoritation by low-cost handheld NIR

Abstract

The technological development of low-cost handheld spectroscopic instruments is allowing the incorporation of these techniques in industrial environments as consumer devices through intelligent applications easily manageable by the user. In this work, a low-cost handheld NIR spectroscopy equipment together with chemometric techniques and the development of a software application, for the management of spectra and prediction of results, has shown its ability to carry out the monitoring of the ripening of an olive grove parcel intended for the production of olives for oil mills and based on the evolution of the oil formed in the fruit. The NIR equipment was used to scan the olive fruits directly on the trees, with the help of an application installed on a smartphone. The spectra obtained are sent by e-mail from the smart device to a computer running the application developed to predict the values of wet fat and moisture contents of the olives. Previously, the calibration and validation of this equipment were carried out by chemometrics methods, obtaining the corresponding models based on regression by Partial Least Squares (PLS). The results have shown that the use of low-cost hand-held NIR equipment can be an invaluable aid in determining the optimum time to harvest olives for oil mills, and a tool essential in the development and application of precision agriculture (Agriculture 4.0).