https://doi.org/10.17113/ftb.58.01.20.6374

Modelling the Inactivation and Possible Regrowth of Salmonella enterica Treated with Chlorophyllin-Chitosan Complex and Visible Light

María Isabel Rodríguez-López¹, Vicente M. Gómez-López², Viktorija Lukseviciute³and Zivile Luksiene^3,4*

¹Departamento de Ciencia y Tecnología de Alimentos, Universidad Católica de Murcia (UCAM), Campus de los Jerónimos 135, 30107 Guadalupe, Murcia, Spain

²Cátedra Alimentos para la Salud, Universidad Católica de Murcia (UCAM), Campus de los Jerónimos 135, 30107 Guadalupe, Murcia, Spain

³Institute of Computer Science, Vilnius University, Didlaukio g. 47, 08303 Vilnius, Lithuania

⁴Institute of Photonics and Nanotechnology, Vilnius University, Saulėtekio 10, 10223 Vilnius, Lithuania

Article history:

Received: 20 May 2019

Accepted: 17 February 2020

Key words:

photosensitization, microbial modelling, treatment with chlorophyllin and chitosan complex, Salmonella enterica, microbial inactivation

Summary:

The study focuses on predictive modelling of inactivation of Salmonella enterica aftertreatment with chlorophyllin-chitosan complex and visible light. Salmonella cells were incubatedwith chlorophyllin-chitosan complex (0.001 % chlorophyllin and 0.1 % chitosan)for different times (5-60 min) and then illuminated with visible light (λ=405 nm, He=38 J/cm2). Inactivation curves and post-treatment regrowth curves were built based on microbiologicalviability tests and data were fitted to ten inactivation and two regrowth models.The photoactivated complex reduced Salmonella population, which were unable toregrow. Weibull and Baranyi models were the best to describe the inactivation and regrowthkinetics respectively. In conclusion, data from the kinetic analysis and predictivemodelling confirmed that photoactivated chlorophyllin-chitosan complex is a promisingnon-thermal approach for inactivation of Gram-negative pathogens, since no bacterialregrowth after treatment has been predicted.