title: Irradiance and Temperature Influence the Bactericidal Effect of 460-Nanometer Light-Emitting Diodes on Salmonella in Orange Juice.
abstract: Blue light-emitting diodes (LEDs) have been known to produce an antibacterial effect on various pathogenic bacteria. To extend this application to foods, blue 460-nm LEDs were evaluated for their antibacterial effect on Salmonella in orange juice. A cocktail of Salmonella enterica serovars Gaminara, Montevideo, Newport, Typhimurium, and Saintpaul was inoculated into pasteurized orange juice and illuminated with 460-nm LEDs at irradiances of 92, 147.7, and 254.7 mW/cm(2) and temperatures of 4, 12, and 20°C. Subsequently, linear, Weibull, and Gompertz models were fitted to the resultant survival curves. The color of the orange juice during illumination was also monitored. It was observed that irradiance and temperature both influenced the inactivation of Salmonella, which ranged from 2 to 5 log CFU/ml. The inactivation kinetics was best described by the Weibull model. An irradiance of 92 mW/cm(2) and temperatures of 12 and 20°C were the most bactericidal combinations, with D-values of 1,580 and 2,013 J/cm(2), respectively. Significant color changes were also observed after illumination; these changes could be minimized by choosing appropriate irradiance and temperature. These results demonstrate the potential of 460-nm LEDs for the preservation of fruit juices in the retail markets and their utility in minimizing the risk of salmonellosis.
authors.affiliation: Food Science & Technology Programme, Department of Chemistry, National University of Singapore, Science Drive 4, Singapore 117543.
authors.forename: Vinayak
authors.initials: V
authors.lastname: Ghate
authors.affiliation: Food Science & Technology Programme, Department of Chemistry, National University of Singapore, Science Drive 4, Singapore 117543.
authors.forename: Amit
authors.initials: A
authors.lastname: Kumar
authors.affiliation: Food Science & Technology Programme, Department of Chemistry, National University of Singapore, Science Drive 4, Singapore 117543; National University of Singapore (Suzhou) Research Institute, No. 377 Linquan Street, Suzhou Industrial Park, Suzhou, Jiangsu, People's Republic of China 215123.
authors.forename: Weibiao
authors.initials: W
authors.lastname: Zhou
authors.affiliation: Food Science & Technology Programme, Department of Chemistry, National University of Singapore, Science Drive 4, Singapore 117543; National University of Singapore (Suzhou) Research Institute, No. 377 Linquan Street, Suzhou Industrial Park, Suzhou, Jiangsu, People's Republic of China 215123;, Email: chmyukhg@nus.edu.sg.
authors.forename: Hyun-Gyun
authors.initials: HG
authors.lastname: Yuk
mesh_terms: D032084:Citrus sinensis / Q000737:chemistry / Q000382:microbiology*; D015169:Colony Count, Microbial; D005514:Food Irradiation; D005519:Food Preservation / Q000379:methods*; D000067030:Fruit and Vegetable Juices / Q000382:microbiology*; D008027:Light; D012475:Salmonella / Q000254:growth & development / Q000528:radiation effects*; D013696:Temperature