Ultraviolet Treatment of Orange Juice to Inactivate <i>E. coli</i> O157:H7 as Affected by Native Microflora

Autores
Oteiza, Juan Martín; Giannuzzi, Leda; Zaritzky, Noemí Elisabet
Año de publicación
2010
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
The effect of yeast concentration on ultraviolet (UV) inactivation of five strains of Escherichia coli O157:H7 from different sources, inoculated both individually and simultaneously in orange juice, was analyzed and mathematically modeled. The presence of yeast cells in orange juice decreases the performance of UV radiation on E. coli inactivation. UV absorption coefficients in the juice increased with increasing yeast concentration, and higher UV doses were necessary to inactivate bacterial strains. UV intensities of I = 3.00 ± 0.3 mW/cm² and exposure times (t) between 0 and 10 min were applied; radiation doses (energy, E = I × t) ranging between 0 and 2 J/cm² were measured using a UV digital radiometer. All the tested individual strains showed higher resistance to the treatment when UV radiation was applied at 4 °C in comparison to 20 °C. UV inactivation of E. coli O157:H7 individual strain was satisfactory fitted with a first order kinetic model. A linear relationship was found between UV absorptivities and D values (radiation doses required to decrease microbial population by 90%) for each strain. The dose required to reach 5-log reduction for the most unfavorable conditions that is the most UV resistant strain, and maximum background yeast concentration was 2.19 J/cm² at 4 °C (corresponding to 11 min of UV treatment) and 2.09 J/cm² at 20 °C (corresponding to 10.55 min of UV treatment). When a cocktail of strains was inoculated in orange juice, the logistic equation was the best model that fits the experimental results due to the deviation from the log-linear kinetics. The UV resistance between strain cocktail and single strain were mathematically compared. Slopes of the decline curves for strain cocktail at high UV doses were lower than the slopes of the log-linear equation calculated for the individual strains, even for the most resistant one. Therefore, microbial inactivation tests using a cocktail of strains are particularly important to determine the performance of the UV inactivation treatment.
Centro de Investigación y Desarrollo en Criotecnología de Alimentos
Facultad de Ingeniería
Materia
Ciencias Exactas
Química
UV radiation
Escherichia coli O157:H7
Orange juice
Yeast concentration
Temperature
Mathematical modeling
D values
Nivel de accesibilidad
acceso abierto
Condiciones de uso
http://creativecommons.org/licenses/by/4.0/
Repositorio
SEDICI (UNLP)
Institución
Universidad Nacional de La Plata
OAI Identificador
oai:sedici.unlp.edu.ar:10915/145211

id SEDICI_cd78f5f49a86ef6642cb3e9903c8bf6a
oai_identifier_str oai:sedici.unlp.edu.ar:10915/145211
network_acronym_str SEDICI
repository_id_str 1329
network_name_str SEDICI (UNLP)
spelling Ultraviolet Treatment of Orange Juice to Inactivate <i>E. coli</i> O157:H7 as Affected by Native MicrofloraOteiza, Juan MartínGiannuzzi, LedaZaritzky, Noemí ElisabetCiencias ExactasQuímicaUV radiationEscherichia coli O157:H7Orange juiceYeast concentrationTemperatureMathematical modelingD valuesThe effect of yeast concentration on ultraviolet (UV) inactivation of five strains of <i>Escherichia coli</i> O157:H7 from different sources, inoculated both individually and simultaneously in orange juice, was analyzed and mathematically modeled. The presence of yeast cells in orange juice decreases the performance of UV radiation on <i>E. coli</i> inactivation. UV absorption coefficients in the juice increased with increasing yeast concentration, and higher UV doses were necessary to inactivate bacterial strains. UV intensities of I = 3.00 ± 0.3 mW/cm² and exposure times (t) between 0 and 10 min were applied; radiation doses (energy, E = I × t) ranging between 0 and 2 J/cm² were measured using a UV digital radiometer. All the tested individual strains showed higher resistance to the treatment when UV radiation was applied at 4 °C in comparison to 20 °C. UV inactivation of <i>E. coli</i> O157:H7 individual strain was satisfactory fitted with a first order kinetic model. A linear relationship was found between UV absorptivities and D values (radiation doses required to decrease microbial population by 90%) for each strain. The dose required to reach 5-log reduction for the most unfavorable conditions that is the most UV resistant strain, and maximum background yeast concentration was 2.19 J/cm² at 4 °C (corresponding to 11 min of UV treatment) and 2.09 J/cm² at 20 °C (corresponding to 10.55 min of UV treatment). When a cocktail of strains was inoculated in orange juice, the logistic equation was the best model that fits the experimental results due to the deviation from the log-linear kinetics. The UV resistance between strain cocktail and single strain were mathematically compared. Slopes of the decline curves for strain cocktail at high UV doses were lower than the slopes of the log-linear equation calculated for the individual strains, even for the most resistant one. Therefore, microbial inactivation tests using a cocktail of strains are particularly important to determine the performance of the UV inactivation treatment.Centro de Investigación y Desarrollo en Criotecnología de AlimentosFacultad de Ingeniería2010-08info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdf603-614http://sedici.unlp.edu.ar/handle/10915/145211enginfo:eu-repo/semantics/altIdentifier/issn/1935-5130info:eu-repo/semantics/altIdentifier/issn/1935-5149info:eu-repo/semantics/altIdentifier/doi/10.1007/s11947-009-0194-yinfo:eu-repo/semantics/reference/hdl/10915/137701info:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by/4.0/Creative Commons Attribution 4.0 International (CC BY 4.0)reponame:SEDICI (UNLP)instname:Universidad Nacional de La Platainstacron:UNLP2025-09-29T11:32:16Zoai:sedici.unlp.edu.ar:10915/145211Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-29 11:32:17.16SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv Ultraviolet Treatment of Orange Juice to Inactivate <i>E. coli</i> O157:H7 as Affected by Native Microflora
title Ultraviolet Treatment of Orange Juice to Inactivate <i>E. coli</i> O157:H7 as Affected by Native Microflora
spellingShingle Ultraviolet Treatment of Orange Juice to Inactivate <i>E. coli</i> O157:H7 as Affected by Native Microflora
Oteiza, Juan Martín
Ciencias Exactas
Química
UV radiation
Escherichia coli O157:H7
Orange juice
Yeast concentration
Temperature
Mathematical modeling
D values
title_short Ultraviolet Treatment of Orange Juice to Inactivate <i>E. coli</i> O157:H7 as Affected by Native Microflora
title_full Ultraviolet Treatment of Orange Juice to Inactivate <i>E. coli</i> O157:H7 as Affected by Native Microflora
title_fullStr Ultraviolet Treatment of Orange Juice to Inactivate <i>E. coli</i> O157:H7 as Affected by Native Microflora
title_full_unstemmed Ultraviolet Treatment of Orange Juice to Inactivate <i>E. coli</i> O157:H7 as Affected by Native Microflora
title_sort Ultraviolet Treatment of Orange Juice to Inactivate <i>E. coli</i> O157:H7 as Affected by Native Microflora
dc.creator.none.fl_str_mv Oteiza, Juan Martín
Giannuzzi, Leda
Zaritzky, Noemí Elisabet
author Oteiza, Juan Martín
author_facet Oteiza, Juan Martín
Giannuzzi, Leda
Zaritzky, Noemí Elisabet
author_role author
author2 Giannuzzi, Leda
Zaritzky, Noemí Elisabet
author2_role author
author
dc.subject.none.fl_str_mv Ciencias Exactas
Química
UV radiation
Escherichia coli O157:H7
Orange juice
Yeast concentration
Temperature
Mathematical modeling
D values
topic Ciencias Exactas
Química
UV radiation
Escherichia coli O157:H7
Orange juice
Yeast concentration
Temperature
Mathematical modeling
D values
dc.description.none.fl_txt_mv The effect of yeast concentration on ultraviolet (UV) inactivation of five strains of <i>Escherichia coli</i> O157:H7 from different sources, inoculated both individually and simultaneously in orange juice, was analyzed and mathematically modeled. The presence of yeast cells in orange juice decreases the performance of UV radiation on <i>E. coli</i> inactivation. UV absorption coefficients in the juice increased with increasing yeast concentration, and higher UV doses were necessary to inactivate bacterial strains. UV intensities of I = 3.00 ± 0.3 mW/cm² and exposure times (t) between 0 and 10 min were applied; radiation doses (energy, E = I × t) ranging between 0 and 2 J/cm² were measured using a UV digital radiometer. All the tested individual strains showed higher resistance to the treatment when UV radiation was applied at 4 °C in comparison to 20 °C. UV inactivation of <i>E. coli</i> O157:H7 individual strain was satisfactory fitted with a first order kinetic model. A linear relationship was found between UV absorptivities and D values (radiation doses required to decrease microbial population by 90%) for each strain. The dose required to reach 5-log reduction for the most unfavorable conditions that is the most UV resistant strain, and maximum background yeast concentration was 2.19 J/cm² at 4 °C (corresponding to 11 min of UV treatment) and 2.09 J/cm² at 20 °C (corresponding to 10.55 min of UV treatment). When a cocktail of strains was inoculated in orange juice, the logistic equation was the best model that fits the experimental results due to the deviation from the log-linear kinetics. The UV resistance between strain cocktail and single strain were mathematically compared. Slopes of the decline curves for strain cocktail at high UV doses were lower than the slopes of the log-linear equation calculated for the individual strains, even for the most resistant one. Therefore, microbial inactivation tests using a cocktail of strains are particularly important to determine the performance of the UV inactivation treatment.
Centro de Investigación y Desarrollo en Criotecnología de Alimentos
Facultad de Ingeniería
description The effect of yeast concentration on ultraviolet (UV) inactivation of five strains of <i>Escherichia coli</i> O157:H7 from different sources, inoculated both individually and simultaneously in orange juice, was analyzed and mathematically modeled. The presence of yeast cells in orange juice decreases the performance of UV radiation on <i>E. coli</i> inactivation. UV absorption coefficients in the juice increased with increasing yeast concentration, and higher UV doses were necessary to inactivate bacterial strains. UV intensities of I = 3.00 ± 0.3 mW/cm² and exposure times (t) between 0 and 10 min were applied; radiation doses (energy, E = I × t) ranging between 0 and 2 J/cm² were measured using a UV digital radiometer. All the tested individual strains showed higher resistance to the treatment when UV radiation was applied at 4 °C in comparison to 20 °C. UV inactivation of <i>E. coli</i> O157:H7 individual strain was satisfactory fitted with a first order kinetic model. A linear relationship was found between UV absorptivities and D values (radiation doses required to decrease microbial population by 90%) for each strain. The dose required to reach 5-log reduction for the most unfavorable conditions that is the most UV resistant strain, and maximum background yeast concentration was 2.19 J/cm² at 4 °C (corresponding to 11 min of UV treatment) and 2.09 J/cm² at 20 °C (corresponding to 10.55 min of UV treatment). When a cocktail of strains was inoculated in orange juice, the logistic equation was the best model that fits the experimental results due to the deviation from the log-linear kinetics. The UV resistance between strain cocktail and single strain were mathematically compared. Slopes of the decline curves for strain cocktail at high UV doses were lower than the slopes of the log-linear equation calculated for the individual strains, even for the most resistant one. Therefore, microbial inactivation tests using a cocktail of strains are particularly important to determine the performance of the UV inactivation treatment.
publishDate 2010
dc.date.none.fl_str_mv 2010-08
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
Articulo
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://sedici.unlp.edu.ar/handle/10915/145211
url http://sedici.unlp.edu.ar/handle/10915/145211
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/issn/1935-5130
info:eu-repo/semantics/altIdentifier/issn/1935-5149
info:eu-repo/semantics/altIdentifier/doi/10.1007/s11947-009-0194-y
info:eu-repo/semantics/reference/hdl/10915/137701
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International (CC BY 4.0)
eu_rights_str_mv openAccess
rights_invalid_str_mv http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International (CC BY 4.0)
dc.format.none.fl_str_mv application/pdf
603-614
dc.source.none.fl_str_mv reponame:SEDICI (UNLP)
instname:Universidad Nacional de La Plata
instacron:UNLP
reponame_str SEDICI (UNLP)
collection SEDICI (UNLP)
instname_str Universidad Nacional de La Plata
instacron_str UNLP
institution UNLP
repository.name.fl_str_mv SEDICI (UNLP) - Universidad Nacional de La Plata
repository.mail.fl_str_mv alira@sedici.unlp.edu.ar
_version_ 1844616202314317824
score 13.070432