Format

Send to

Choose Destination
J Dairy Sci. 2020 Feb;103(2):1261-1268. doi: 10.3168/jds.2019-16758. Epub 2019 Nov 20.

Inactivation of milk-borne pathogens by blue light exposure.

Author information

1
Department of Internal Medicine, School of Veterinary Medicine and Animal Science, University of Sao Paulo, Sao Paulo, SP, Brazil, 05508-270.
2
Department of Biochemistry, Institute of Chemistry, University of Sao Paulo, Sao Paulo, SP, Brazil, 05513-970.
3
Department of Preventive Veterinary Medicine and Animal Health, School of Veterinary Medicine and Animal Science, University of Sao Paulo, Sao Paulo, SP, Brazil, 05508-270.
4
Brazilian Synchrotron Light Laboratory, Brazilian Center for Research in Energy and Materials, 13083-970, Campinas, SP, Brazil.
5
Center for Lasers and Applications, Nuclear and Energy Research Institute, Sao Paulo, SP, Brazil, 05508-000.
6
Department of Clinical and Toxicological Analysis, School of Pharmaceutical Sciences, University of Sao Paulo, Sao Paulo, SP, Brazil, 05508-000; Department of Microbiology, Institute for Biomedical Sciences, University of Sao Paulo, São Paulo, SP, Brazil, 05508-000.
7
Department of Clinical and Toxicological Analysis, School of Pharmaceutical Sciences, University of Sao Paulo, Sao Paulo, SP, Brazil, 05508-000; BioLambda, Scientific and Commercial Ltd., Sao Paulo, SP, Brazil, 05360-030. Electronic address: caetanosabino@gmail.com.

Abstract

Food safety and quality management play a pivotal role in the dairy industry. Milk is a highly nutritious food that also provides an excellent medium for growth of pathogenic microorganisms. Thus, dairy industry focuses most of their processes and costs on keeping contamination levels as low as possible. Thermal processes for microbial decontamination may be effective; however, they cannot provide excellent organoleptic, nutritional, and decontamination properties simultaneously. In this scenario, microbial inactivation by exposure to blue light is a promising alternative method in the food industry due to its intrinsic antimicrobial properties free of any thermal effect. Therefore, this study aimed to determine the inactivation kinetics induced by blue light (λ = 413 nm) against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella Typhimurium, and Mycobacterium fortuitum cells suspended in whole milk or saline solution. We also performed a series of optic spectroscopies to investigate possible degradation of milk components. All species were sensitive to photoinactivation suspended either in saline solution or milk. Inactivation kinetics differs significantly depending on the suspension medium and each species is differently affected. All bacterial species tested presented more than 5 log10 of inactivation within less than 2 h of irradiation (720 J/cm2). Infrared spectroscopy did not reveal any significant alteration in any of the milk constituents (e.g., sugars, proteins, and lipids). Riboflavin (vitamin B2) was the only significantly degraded constituent found. Therefore, we conclude that microbial inactivation performed by blue light presents extraordinary potential for processes in the dairy industry.

KEYWORDS:

food borne; food pathogen; milk decontamination; photoinactivation; visible light

PMID:
31759598
DOI:
10.3168/jds.2019-16758

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center