Characterization and Multivariate Analysis of Physical Properties of Processing Peaches

Abstract

Characterization of physical properties of fruits represents the first vital step to ensure optimal performance of fruit processing operations and is also a prerequisite in the development of new processing equipment. In this study, physical properties of engineering significance to processing of three popular cultivars of clingstone peaches were evaluated, including dimensional parameters, mass, dimensional ratios, aspect ratio, elongation index, sphericity, bulk density, texture, color, and flavor. Based on these physical properties, multivariate analysis of variance (MANOVA), canonical variate analysis (CVA), principal component analysis (PCA), and partial least squares and linear discriminate analysis (PLS-LDA) were applied to qualitatively and quantitatively discriminate the cultivar difference. Results showed that the studied peach cultivars had significantly different (p < 0.05) geometric characteristics. The peaches can be classified based on the cheek diameter (Dc) into three different size categories, including small- (Dc less than 60 mm), medium- (Dc between 60 mm and 70 mm), and large- (Dc higher than 70 mm) sized peaches. The peach flesh firmness significantly (p < 0.05) decreased with the increase of peach size, while the pit dimensions were independent of peach size. There were no apparent distinctions in color characteristics, bulk density, and sugar content among the three cultivars. The measurements and quantitative discrimination of peach properties in this study would benefit equipment design and process innovation to enhance the processing efficiency and quality of processed peaches.