Search

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.