Title: Review of Research on Post Irradiation Fruit Quality of Blueberries and Peaches Author
Submitted to: Technical Report
Publication Type: Abstract Only
Publication Acceptance Date: May 1, 2010
Publication Date: September 1, 2010
Citation: Wall, M.M. 2010. Review of Research on Post Irradiation Fruit Quality of Blueberries and Peaches. USDA, APHIS, Plant Protection and Quarantine Rpt. 9pp. Technical Abstract: The commercial use of irradiation is accelerating with the approval of low dose generic treatments for insect disinfestations and the availability of irradiation facilities. Commercial adoption of irradiation treatment requires an understanding of the radiotolerance limits for individual commodities, as well as the multiple factors that may mediate phytotoxicity. Careful attention to dosimetry and fruit physiology is needed to accurately determine phytotoxic thresholds. For blueberries and peaches, cultivar differences and slight variations in maturity or initial quality at harvest can modify radiotolerance. A review of existing literature revealed that highbush blueberry tolerance to irradiation is cultivar-dependent. A southern highbush variety (Sharpblue) and rabbiteye cultivars (Climax, Tifblue, Brightwell) tolerated irradiation at doses below 750 Gy without loss of fruit market quality. Doses greater than 1000 Gy adversely affected fruit texture and flavor, contributing to consumer rejection. For peaches, irradiation accelerated ripening, and doses above 600 Gy caused internal breakdown, softening, and aroma changes. Peaches treated with 650 to 750 Gy tended to have off-odors and lack the characteristic peach aroma. Blueberries and peaches may tolerate quarantine treatment at the generic 400 Gy dose if the commercial dose uniformity ratio is below 1.5 to 1.8. Also, testing under simulated or actual shipping conditions is needed to determine the impact of irradiation-induced softening on transit injury of blueberries and peaches.