Using non-destructive techniques for assessing fruit ripeness: Implications for pharmacognosy and active compound analysis

Abstract

Fruit ripeness assessment is critical for both food industries and pharmacognosy, where the stage of maturity strongly influences the concentration and stability of bioactive compounds. Conventional destructive methods, while accurate, are unsuitable for large-scale and real-time monitoring due to their time-consuming and invasive nature. This study explored the application of non-destructive techniques (NDTs), particularly visible-near infrared (Vis-NIR) spectroscopy and hyperspectral imaging, for evaluating ripeness and predicting pharmacognostically relevant compounds in mango, guava, and pomegranate. Fruits were collected at three ripeness stages and analyzed through destructive reference assays for phenolics, flavonoids, soluble solids, and antioxidant activity. Spectral data were processed using chemometric models including principal component analysis and partial least squares regression. Results demonstrated strong predictive performance for total phenolics with coefficients of determination (R² ≈ 0.92), root mean square error of prediction (RMSEP ≈ 6-8 mg GAE/100 g), and residual predictive deviation (RPD ≈ 3.0-3.7), indicating robust analytical capability. Stage-wise comparisons revealed that mid-ripe fruits consistently exhibited the highest phenolic and flavonoid concentrations, whereas soluble solids increased progressively toward full ripeness. Classification of ripeness stages based on NIR-derived indices achieved an overall accuracy of ~90%, with minor misclassifications at the immature-mid boundary. Bland-Altman analysis confirmed negligible prediction bias, underscoring the reliability of NDTs as surrogates for destructive assays. These findings suggest that integrating non-destructive spectroscopy into pharmacognostic workflows can optimize harvest timing, standardize active compound concentrations, and ensure reproducibility in herbal medicine preparation. The study highlights the potential of NDTs to advance sustainable and quality-assured supply chains for fruits of therapeutic importance.