Investigating non-destructive quantification and characterization of pomegranate fruit internal structure using X-ray computed tomography

Abstract

In this study, X-ray computed tomography (CT) coupled with image analysis techniques was investigated for non-destructive characterization and quantification of internal structure of intact pomegranate fruit (cv. Shani-Yonay). X-ray tomograms of intact fruit were acquired using a V|Tome|X L240 commercial X-ray CT system based on X-ray radiation generated from a source voltage of 200kV with the electron current set at 100μA. Two-dimensional (2D) radioscopic images were acquired with a microfocus direct X-ray tube and used to reconstruct three-dimensional (3D) images to quantify volumes occupied by air space, albedo, and arils, using image processing software. The calculated volumes for these fruit fractions were 7.82±1.09, 167.29±16.54, and 182.11±17.04mL, estimated to contribute 2.22, 46.86 and 50.92% of total fruit volume, respectively. Destructive validation data were similar to non-destructive data, with volumes for albedo and arils of 166.08±14.69 and 170.58±14.25mL, respectively, contributing 46.07 and 47.32% of total fruit volume. The remaining 6.61% of total fruit volume tested destructively could be due to the presence of air space and calyx. This work has demonstrated the capability of X-ray CT with image analysis as a useful non-destructive technique to study the quantity and distribution of edible and non-edible portions of pomegranate fruit.