This study evaluates the potential of integrating visible and near-infrared (visNIR) spectroscopy, color analysis, and firmness testing for non-destructive tomato quality assessment and shelf-life prediction. Tomato fruit (cv. HM1823) harvested at four ripening stages were monitored over 12 days at 22 °C to investigate ripening stage-specific variations in key quality parameters, including color (hue angle), firmness (compression), and nutritional composition (pH, soluble solids content, and titratable acidity ratio). Significant changes in these parameters during storage highlighted the need for advanced tools to monitor and predict quality attributes. Spectral data (340–2500 nm) captured using advanced and cost-effective portable spectroradiometers, coupled with chemometric models such as partial least squares regression (PLSR), demonstrated reliable predictions of shelf-life and nutritional quality. The near-infrared spectrum (900–1700 nm) was particularly effective, with variable selection methods such as genetic algorithm (GA) and variable importance in projection (VIP) scores enhancing model accuracy. This study highlights the promising role of visNIR spectroscopy as a rapid, non-destructive tool for optimizing postharvest management in tomato. By enabling real-time quality assessments, these technologies support sustainable agricultural practices through improved decision-making, reduced postharvest losses, and enhanced consumer satisfaction. The findings also validate the utility of affordable spectroradiometers, offering practical solutions for stakeholders aiming to balance cost efficiency and reliability in postharvest quality monitoring.

External and internal changes in tomato fruit harvested at various ripening stages (from mature green to red ripe) were monitored during postharvest storage at 22 oC for 12 days. Non-destructive measurements of color, compression firmness and spectral reflectance data were captured with two portable, but differently technologically advanced spectroradiometers (a PSR+ 3500, Spectral Evolution and a DLP NIR Nano Scan, Texas Instruments) spectroradiometers in the visible-near infrared (visNIR) (340-2500 nm) or only the NIR (900-1700 nm) region. Significant changes in color, firmness, pH and soluble solids to titratable acidity ratio were observed during storage, especially in the less ripe fruits and were reliably assessed by all nondestructive techniques, especially by the spectral reflectance data captured at the 340-2500 nm part with the most sophisticated device. In general, visNIR spectroscopy, combined with chemometric techniques, is a powerful non-destructive method for assessing tomato quality and predicting shelf life. Although using both the visible and the near infrared part of the spectrum (340-2500 nm) provides more accurate assessments, the NIR part (900-1700 nm) alone can support reliable predictions, while the consumers are not capable of perceiving most of the changes that accompany postharvest ripening before consuming the products.