Chemometric Classification of Citrus Juices of Moroccan Cultivars by Infrared Spectroscopy

Fourier transform - infrared (FTIR) spectroscopy in connection with chemometric methodologies was used as a fast and direct analytical approach to classify citrus cultivars by the measurements on their juice. Modern multivariate analysis responds to the current needs for economic, simple, and fast methods able to classify new unknown samples with great accuracy. A set of 135 samples of citrus juice, representative of three cultivars (Hamlin, Muska, and Valencia), all picked in the same geographical area of Morocco, were analysed. Chemometric discrimination of the juice samples was achieved by principal component analysis (PCA) performed on the FTIR spectral data from the juice samples, showing an explained variance of 97.84% by considering only 2 PCs. A fully correct classification of the three Moroccan cultivars was then obtained by using Partial Least Square-Discriminant Analysis (PLS-DA) modelling procedure.