New post-harvest aproach for high quality fresh ‘Medjhool’ date

Abstract In Israel, ‘ Medjhool ’ has become the major date fruit variety. In a certain ripeness stage they become super succulent, juicy, tasty (“Super Fresh” ‘ Medjhool ’) and have a high market value compared to regular ‘ Medjhool ’ dates. At this particular stage, the dates are very difficult to handle (picking up, removing etc.). Harvesting of ‘ Medjhool ’ dates after having matured but before ripening (Khalal ‘ Medjhool ’) followed by suitable postharvest treatment to enforce ripening, might provide farmers a method to produce a high quality product. At this pre-ripe stage, dates' total soluble solid (TSS) content varies considerably. The objectives of this study were to find an appropriate post-harvest treatment to produce “Super Fresh” ‘Medjhool ’ dates from the Khalal fruits and to develop a method for online sorting of Khalal ‘ Medjhool ’ dates according to their TSS content using a mini NIR spectrometer. A cells' conveyor, an automatic sorting apparatus and a NIR (850–1880 nm) scanning device were designed and constructed, simulating a real sorting operation. Spectral models for TSS prediction were developed, based on Partial Least Squares regression. The root mean square prediction error of TSS was in the range of 0.9–1.6% in the different prediction models. This study establishes the basis for sorting dates for consequent postharvest treatment, using NIR spectroscopy, in the production process of “Super Fresh” ‘ Medjhool ’ dates.