Feasibility Study of the Use of Handheld NIR Spectrometer for Simultaneous Authentication and Quantification of Quality Parameters in Intact Pineapple Fruits

Abstract

The potential of predicting maturity using total soluble solids (TSS) and identifying organic from inorganic pineapple fruits based on near-infrared (NIR) spectra fingerprints would be beneficial to farmers and consumers alike. In this study, a portable NIR spectrometer and chemometric techniques were combined to simultaneously identify organically produced pineapple fruits from conventionally produced ones (thus organic and inorganic) and also predict total soluble solids. A total of 90 intact pineapple fruits were scanned with the NIR spectrometer while a digital refractometer was used to measure TSS from extracted pineapple juice. After attempting several preprocessing techniques, multivariate calibration models were built using principal component analysis (PCA), K-nearest neighbor (KNN), and linear discriminant analysis (LDA) to identify the classes (organic and conventional pineapple fruits) while partial least squares regression (PLSR) method was used to determine TSS of the fruits. Among the identification techniques, the MSC-PCA-LDA model accurately identified organic from conventionally produced fruits at 100% identification rate. For quantification of TSS, the MSC-PLSR model gave Rp = 0.851 and RMSEC = 0.950 °Brix, and Rc = 0.854 and RMSEP = 0.842 °Brix at 5 principal components in the calibration set and prediction set, respectively. The results generally indicated that portable NIR spectrometer coupled with the appropriate chemometric tools could be employed for rapid nondestructive examination of pineapple quality and also to detect pineapple fraud due to mislabeling of conventionally produced fruits as organic ones. This would be helpful to farmers, consumers, and quality control officers.

Principles and Applications of Miniaturized Near‐Infrared (NIR) Spectrometers

“…Considerable attention has been given to fruit analyses by portable NIR spectroscopy [69–73] . Among others, the capacity of compact spectrometers to successfully determining quality parameters, [69] monitoring moisture content and controlling drying processes, [70,73] determining and authenticating fruit varieties, [71] as well as quantitatively determining various properties of fruits [70–72] were demonstrated in the recent literature. Similarly high attention was given to the advantages of portable NIR spectroscopy in the analysis of grains.…”

Physicochemical analysis and adulteration detection in Malaysia stingless bee honey using a handheld near‐infrared spectrometer

“…All the data under the calibration set and prediction set are randomly picked by Orange Data Mining to prevent bias occurred (Amuah et al, 2019;Mohamed et al, 2019).…”

An overview of non-destructive approaches for quality determination in pineapples

“…The samples were distinguished according to the bioactivity using the PCA model with the spectra collected from the FT-IR spectroscopy. Amuah et al (2019) discussed the application of NIR spectroscopy to evaluate total soluble solids for organic and inorganic pineapples. Multivariate algorithm models were established using PCA and LDA classifiers to accurately distinguished between organic and inorganic pineapples with the classification rate of 100 %.…”