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ARS Home » Northeast Area » Wyndmoor, Pennsylvania » Eastern Regional Research Center » Microbial and Chemical Food Safety » Research » Publications at this Location » Publication #314908

Title: Application of ultraviolet-C light on oranges for the inactivation of postharvest wound pathogens

item GUNDUZ, GULTEN - Ege University
item Juneja, Vijay
item PAZIRA, FIKRET - Ege University

Submitted to: Food Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/25/2014
Publication Date: 4/11/2015
Publication URL:
Citation: Gunduz, G.T., Juneja, V.K., Pazira, F. 2015. Application of ultraviolet-C light on oranges for the inactivation of postharvest wound pathogens. Food Control. DOI: 10.1016/j.foodcont.2015.04.003.

Interpretive Summary: Use of pesticides to control post-harvest diseases may result in development of resistant mold strains. This emphasizes the need to develop alternative interventions to control molds. We assessed the efficacy of ultraviolet-C light to inactivate two pathogenic molds, Penicillium digitatum and Penicillium italicum, on oranges. UV-C light effectively decreased the number of P. digitatum and P. italicum spores and the treatment dose designed to reduce P. italicum spores will be adequate to reduce P. digitatum spores. These findings will assist food industry and regulatory agencies to incorporate UV-C treatment as one of the preservation steps to effectively eliminate postharvest wound pathogens.

Technical Abstract: Germicidal effects of ultraviolet-C (UV-C) light on the postharvest wound pathogens of citrus fruits namely Penicillium digitatum and Penicillium italicum were investigated. P. digitatum and P. italicum spores were inoculated (4.00 – 4.50 log cfu/ orange) onto Washington navel oranges (Citrus sinensis L. Osbeck cv Washington navel) by using wound and spot inoculation methods and subjected to eight different UV-C doses in the range of 0.26 to 15.84 kJ/m2. Maximum reductions of 2.75 and 3.33 log cfu/orange of P. digitatum were obtained at the UV-C dose of 3.17 kJ/m2 for spot and wound inoculation methods, respectively. P. italicum was more resistant than P. digitatum to UV-C treatments. The results suggest that UV-C treatments designed to reduce P. italicum spores will provide an adequate degree of protection against P. digitatum spores. UV-C light could be an alternative technique for the use of synthetic chemicals to reduce the development of postharvest pathogens of oranges.