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Precise categorization of avocado ripeness plays a vital role in strengthening post-harvest operations and curbing waste throughout agricultural supply networks. The present study centers on constructing a resilient ensemble classification framework employing spectral readings from 120 kilograms of Buccaneer avocados procured from the Royal Project in Chiang Mai, Thailand. The specimens were assessed via near-infrared (NIR) spectroscopy at 18 wavelengths. Five distinct machine learning models—Random Forest, Decision Tree, XGBoost, Gradient Boosting, and Gaussian Mixture Model—were separately trained and subsequently fused into a unified ensemble. Four distinct algorithms were deployed to fine-tune the weighting of each model: Bayesian optimisation, differential evolution, particle swarm optimisation, and grid search. Evaluation metrics covering accuracy, precision, recall, F1-score, confusion matrices, and ROC curves were applied. Grid Search yielded the strongest classification outcomes, securing an accuracy of 82.5% alongside an F1-score of 85.3%, emphasizing the value of weight-refined ensemble learning relative to standalone classifiers. This investigation delivers a scalable and transparent pipeline for non-destructive ripeness identification. The outcomes, notwithstanding constraints related to overfitting and dependency on spectral data integrity, pave the way for eventual real-time field deployment in agriculture.

Mango fruit exists in multiple cultivar types, and the principal maturity markers for quality assessment are total soluble solids (TSS) and pH. The investigation assessed the viability of coupling a handheld NIR spectrometer (NIRS) covering 740-1070 nm with multivariate algorithms and a smartphone to classify mango cultivars and assess their ripeness. A batch of 198 whole mango fruits was scanned using the NIR device; concurrently, a digital refractometer and a pH meter were used to quantify TSS and pH from extracted juice. Following various spectral preprocessing treatments, multivariate classification models—support vector machine (SVM), linear discriminant analysis (LDA), random forest (RF), neural network (NN), and a novel hybrid classifier (LDA-SVM)—were developed for varietal discrimination. Quantitative models predicting TSS and pH were constructed using partial-least-squares regression variants, including interval partial-least-squares (IPLS), synergy partial-least-squares (Si-PLS), and back interval-partial-least-squares (Bi-PLS). For classification, RAW, MC, SNV, FD, and SD preprocessing paired with the LDA-SVM classifier delivered perfect (100 %) varietal recognition in the training set and 97.44 % accuracy in the prediction set. For quantification, the optimal prediction model for both TSS and pH was Si-PLS, achieving R² values of 0.63 and 0.81, respectively and RMSEP values of 1.83 and 0.49, respectively. The study proved that swift, non-invasive estimation of TSS and pH is feasible by integrating a handheld NIR sensor with suitable chemometric analyses.