Kiwifruits ripening assessment by portable hyperspectral devices

This study aimed to evaluate the possibility to utilize portable hyperspectral devices in order to perform fast, reliable, low cost and robust monitoring of kiwifruits ripening both in field and/or in processing storage facilities. This determination is of great interest, not only to assess kiwi taste according to market requirement, but also to set up efficient handling and conservation strategies avoiding loss of product. To reach these goals two different sensing units have been utilized, that is i) a MicroNIR™ JDSU Spectrometer working in the NIR wavelength range 950-1650 nm and ii) a ASD FieldSpec 4 ® Standard-Res field portable spectroradiometer working in the NIR wavelength range 350-2500 nm. Kiwifruits collected spectra have been correlated with classical quality indicators (i.e. Total Soluble Solid Content the Dry Matter content) following a chemiometric approach based on spectra preprocessing, data explorative analysis and Partial Least Square modelling. Kiwifruits ripening characteristics have been satisfactory predicted by both the units. Results have been compared in a costs/benefits perspective taking into account the different sensing architectures, their costs and easiness of use.