Novel non-destructive techniques to characterise fruit internal components and detect the presence of defects

In this study, the application of microfocus X-ray computed tomography (μCT) with a density calibration of homogenous polymeric materials ranging from 0.9-2.2 g cm^-3 and its accuracy for differentiating fruit fractions (albedo and arils) and detecting false codling moth in pomegranate fruit 'Herskawitz' was investigated. A commercial X-ray system with a radiation source of 100 kV and electron current of 200 μA was used to generate two-dimensional (2-D) radioscopic images which were reconstructed into three-dimensional (3-D) volumes. The estimation of the density of pomegranate fruit fractions (arils and albedo) and false codling moth were successfully determined within the calibration range. The density of whole fruit (1.07±0.02 g cm^-3) and fruit fractions (arils 1.12±0.04 and albedo 1.04±0.03 g cm^-3) was significantly higher compared to the codling larva moth (0.94±0.04 g cm^-3) found within the fruit. The predicted mass (g) for arils and albedo were 153.42±34.58 and 104.73±14.56 g respectively, which accounted for an average of 40 and 59% of the total pomegranate fruit mass (259.84±36.90 g). The destructive measurements were similar to that of the μCT predicted data for arils (159.06±33.09 g) and albedo (102.30±11.66 g) with the paired t-test showing no significant difference between the μCT predicted and destructively measured mass. The results thus demonstrated that the developed algorithm can be used to accurately characterise the fruit internal components and detect the presence of false codling moth within pomegranate fruit.