Non-destructive quantification of pomegranate internal quality structures using X-ray computed tomography

L.S. Magwaza, U.L. Opara
Increasing interest in pomegranate fruit has coincided with an increasing consumer demand for consistent supply of safe, nutritious and traceable food products. This demand for quality-assured fruit has spurred the need to develop innovative non-destructive techniques for quality assessment, based on both external and internal quality attributes. In this study, X-ray computed tomography (CT) was investigated for non-invasive characterization and volume quantification of edible (arils) relative to non-edible (albedo) fractions of intact pomegranate fruit. The study was conducted using 'Shani-Yonay' cultivar. X-ray tomograms were acquired using a V|Tome|X L240 commercial X-ray CT system based on X-ray radiation generated from a source voltage of 200 kV and the electron current set at 100 µA. Two-dimensional (2-D) radioscopic images were acquired with a microfocus direct X-ray tube. These 2-D images were used to reconstruct three-dimensional images to quantify volumes occupied by air spaces, albedo, and arils, using image-processing software. The X-ray CT calculated volumes for these fractions were 7.8, 167.3, and 182.1 mL, estimated to respectively contribute 2.2, 46.9 and 50.9% of the total fruit volume. Destructive validation data were similar to X-ray CT calculated data, with volumes for albedo and arils of 158.3 and 162.0 mL, respectively, contributing 46.0 and 47.3% of total volume. The remaining 6.7% of total fruit volume in destructive data was due to air spaces, stem end and calyx. This study demonstrated the capability of X-ray CT as a potential technique to non-destructively characterize structural distribution and quantify volumes of edible to non-edible portions of pomegranate fruit.
Magwaza, L.S. and Opara, U.L. (2016). Non-destructive quantification of pomegranate internal quality structures using X-ray computed tomography. Acta Hortic. 1119, 135-140
DOI: 10.17660/ActaHortic.2016.1119.18
arils, albedo, non-destructive, fruit quality, image analysis, Punica granatum L., air space

Acta Horticulturae