Quality Characteristics of Low-Dose Electron Beam Irradiated-Imported Navel Orange during Storage at Room Temperature (20℃)

Abstract

This study investigated the effects of low-dose electron beam irradiation treatment on the physicochemical and sensorial properties of imported navel oranges during storage at 20°C for 12 days. The samples were irradiated at doses of 0.2, 0.4, 0.6, 0.8, and 1.0 kGy, after which changes in color value, hardness, Brix/acid ratio, total sugar contents, reducing sugar contents, vitamin C contents, and sensory evaluation were investigated. There were no significant differences between non-irradiated and irradiated samples in terms of color value, Brix/acid ratio, total sugar contents, total reducing sugar contents, and vitamin C contents. Hardness of irradiated samples significantly decreased in the early storage period in an irradiation dose-independent manner, and the difference between non-irradiated and irradiated samples decreased again at the end of storage. For the sensory evaluation, there was no significant difference between non-irradiated and irradiated samples up to 0.6 kGy, and all sensory item scores decreased at the end of the storage period regardless of irradiation. These results suggest that electron beam irradiation below 0.6 kGy does not affect physicochemical and sensory properties during storage at 20°C. Thus, electron beam irradiation up to 0.6 kGy applied to imported navel oranges is the optimum dose for minimizing quality changes and disinfestation treatment.

Determination of Quality Parameters and Sensory Attributes of ‘Jaffa’ Oranges Irradiated as Postharvest Quarantine Treatment Throughout Long-Term Cold Storage

“…Total vitamin C content (AA+DHA) of California and Florida varieties is 83 and 63 mg kg -1 , respectively (Vanderslice et al, 1990). Some reports on evaluating the effect of irradiation on vitamin C content of oranges showed that orange, mandarin and acid lime samples were irradiated at 1.5 kGy using gamma rays and the vitamin C contents of these fruit declined by 16 %, 27 % and 29 %, respectively (Ladaniya et al, 2003), in blood oranges, irradiation with 0.25 and 0.5 kGy slowed the loss of ascorbic acid (AA) during six weeks storage, resulting in higher AA levels in oranges irradiated with 0.5 kGy (Khalil et al, 2009), irradiation (0.2 -0.6 kGy) on 'Lane Late' Navel oranges had no effect on vitamin C retention (McDonald et al, 2013), irradiated (0 -0.2 kGy) and non-irradiated Valencia oranges had similar vitamin C content (De Bortoli et al, 2015) and vitamin C was insignificantly different between irradiated (0.2 -1 kGy) and non-irradiated Navel orange fruit (Cho et al, 2015). Our results revealed that gamma irradiation had a significant effect (P <0.05) on the vitamin C level of fruit juice of 'Jaffa' orange in all intervals except 15 d intervals of cold storage (Table 3).…”