Microbial inactivation and cytotoxicity evaluation of UV irradiated coconut water in a novel continuous flow spiral reactor

• Published in: Food research international 2018-01, Vol.103, p.59-67
• Main Authors: Bhullar, Manreet Singh, Patras, Ankit, Kilanzo-Nthenge, Agnes, Pokharel, Bharat, Yannam, Sudheer Kumar, Rakariyatham, Kanyasiri, Pan, Che, Xiao, Hang, Sasges, Michael
• Format: Article
• Language: English
• Subjects: bacteria; Bacteriophage; bacteriophages; beverages; Bio-dosimetry; coconut water; commercialization; Continuous-flow UV reactor; cytotoxicity; Escherichia coli; food industry; food preservation; hepatocytes; horticulture; humans; Inactivation kinetics; intestines; irradiation; linear models; liquids; Listeria monocytogenes; mice; Microbial inactivation; pathogens; prediction; Salmonella Typhimurium; ultraviolet radiation; UV-C irradiation; wavelengths
• ISSN: 0963-9969; 1873-7145
• DOI: 10.1016/j.foodres.2017.10.004

A continuous-flow UV reactor operating at 254nm wave-length was used to investigate inactivation of microorganisms including bacteriophage in coconut water, a highly opaque liquid food. UV-C inactivation kinetics of two surrogate viruses (MS2, T1UV) and three bacteria (E. coli ATCC 25922, Salmonella Typhimurium ATCC 13311, Listeria monocytogenes ATCC 19115) in buffer and coconut water were investigated (D10 values ranging from 2.82 to 4.54mJ·cm−2). A series of known UV-C doses were delivered to the samples. Inactivation levels of all organisms were linearly proportional to UV-C dose (r2>0.97). At the highest dose of 30mJ·cm−2, the three pathogenic organisms were inactivated by >5 log10 (p0.97). Models for predicting log reduction as a function of UV-C irradiation dose were found to be significant (p5-log10.•UV-C irradiation could be an effective alternative for production of beverages.