Classification of date fruit (Phoenix dactylifera, L.) based on chemometric analysis with multivariate approach

Abstract

Date varieties grown in the United Arab Emirates have not been characterized previously as per quality descriptive parameters, which are important for the commercial viability and processing. In this study, 29 analytical and descriptive parameters including morphological date variables (fruit and seed weight, length, volume, diameter, and density), chemical (reducing sugars, organic acids) and textural properties (hardness, adhesive force, resilience, fracturability, and springiness), and color (lightness, redness, yellowness) were investigated for their efficacy in classifying 20 Emirati date varieties at the mature Tamr stage. Chemometric multivariate analysis of the 29 physical–chemical traits of date varieties allowed selection of three traits that were decisive for clustering of samples with similar characteristics. Date fruit color, size, and concentration of malic acid appeared to be the most important parameters for distinguishing date fruits into three homogeneous groups: (i) class 1 (darker color and higher malic acid content), (ii) class 2 (moderate malic acid content and light color), and (iii) class 3 (larger fruits and low malic acid content). The results of this study will guide further studies aiming to explore the relationships between the chemical and physical quality parameters of date fruit, including organic acids and pigments, and fruit color that are identified as the most important fruit classification parameters.