Effectiveness of UV-C light assisted by mild heat on Saccharomyces cerevisiae KE 162 inactivation in carrot-orange juice blend studied by flow cytometry and transmission electron microscopy

The aim of this study was to analyze the effectiveness of UV-C light (0–10.6 kJ/m2) assisted by mild heat treatment (50 °C) on the inactivation of Saccharomyces cerevisiae KE 162 in peptone water and fresh carrot-orange juice blend (pH: 3.8; 9.8°Brix; 707 NTU; absorption coefficient: 0.17 cm−1). Yea...

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Publicado: 2018
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Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_07400020_v73_n_p1_GarciaCarrillo
http://hdl.handle.net/20.500.12110/paper_07400020_v73_n_p1_GarciaCarrillo
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spelling paper:paper_07400020_v73_n_p1_GarciaCarrillo2025-07-30T18:20:58Z Effectiveness of UV-C light assisted by mild heat on Saccharomyces cerevisiae KE 162 inactivation in carrot-orange juice blend studied by flow cytometry and transmission electron microscopy Flow cytometry Mild heat Transmission electron microscopy UV-C light carrot chemistry evaluation study flow cytometry food preservation fruit and vegetable juice growth, development and aging heat microbial viability microbiology procedures radiation response Saccharomyces cerevisiae sweet orange transmission electron microscopy ultrastructure ultraviolet radiation Citrus sinensis Daucus carota Flow Cytometry Food Preservation Fruit and Vegetable Juices Hot Temperature Microbial Viability Microscopy, Electron, Transmission Saccharomyces cerevisiae Ultraviolet Rays The aim of this study was to analyze the effectiveness of UV-C light (0–10.6 kJ/m2) assisted by mild heat treatment (50 °C) on the inactivation of Saccharomyces cerevisiae KE 162 in peptone water and fresh carrot-orange juice blend (pH: 3.8; 9.8°Brix; 707 NTU; absorption coefficient: 0.17 cm−1). Yeast induced damage by single UV-C and mild heat (H) and the combined treatment UV-C/H, was investigated by flow cytometry (FC) and transmission electron microscopy (TEM). When studying induced damage by FC, cells were labeled with fluorescein diacetate (FDA) and propidium iodide (PI) to monitor membrane integrity and esterase activity. UV-C/H provoked up to 4.7 log-reductions of S. cerevisiae; whereas, only 2.6–3.3 log-reductions were achieved by single UV-C and H treatments. FC revealed a shift with treatment time from cells with esterase activity and intact membrane to cells with permeabilized membrane. This shift was more noticeable in peptone water and UV-C/H treated juice. In the UV-C treated juice, double stained cells were detected, suggesting the possibility of being sub-lethally damaged, with compromised membrane but still metabolically active. TEM images of treated cells revealed severe damage, encompassing coagulated inner content, disorganized lumen and cell debris. FC and TEM provided additional information regarding degree and type of damage, complementing information revealed by the traditional plate count technique. © 2018 Elsevier Ltd 2018 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_07400020_v73_n_p1_GarciaCarrillo http://hdl.handle.net/20.500.12110/paper_07400020_v73_n_p1_GarciaCarrillo
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Flow cytometry
Mild heat
Transmission electron microscopy
UV-C light
carrot
chemistry
evaluation study
flow cytometry
food preservation
fruit and vegetable juice
growth, development and aging
heat
microbial viability
microbiology
procedures
radiation response
Saccharomyces cerevisiae
sweet orange
transmission electron microscopy
ultrastructure
ultraviolet radiation
Citrus sinensis
Daucus carota
Flow Cytometry
Food Preservation
Fruit and Vegetable Juices
Hot Temperature
Microbial Viability
Microscopy, Electron, Transmission
Saccharomyces cerevisiae
Ultraviolet Rays
spellingShingle Flow cytometry
Mild heat
Transmission electron microscopy
UV-C light
carrot
chemistry
evaluation study
flow cytometry
food preservation
fruit and vegetable juice
growth, development and aging
heat
microbial viability
microbiology
procedures
radiation response
Saccharomyces cerevisiae
sweet orange
transmission electron microscopy
ultrastructure
ultraviolet radiation
Citrus sinensis
Daucus carota
Flow Cytometry
Food Preservation
Fruit and Vegetable Juices
Hot Temperature
Microbial Viability
Microscopy, Electron, Transmission
Saccharomyces cerevisiae
Ultraviolet Rays
Effectiveness of UV-C light assisted by mild heat on Saccharomyces cerevisiae KE 162 inactivation in carrot-orange juice blend studied by flow cytometry and transmission electron microscopy
topic_facet Flow cytometry
Mild heat
Transmission electron microscopy
UV-C light
carrot
chemistry
evaluation study
flow cytometry
food preservation
fruit and vegetable juice
growth, development and aging
heat
microbial viability
microbiology
procedures
radiation response
Saccharomyces cerevisiae
sweet orange
transmission electron microscopy
ultrastructure
ultraviolet radiation
Citrus sinensis
Daucus carota
Flow Cytometry
Food Preservation
Fruit and Vegetable Juices
Hot Temperature
Microbial Viability
Microscopy, Electron, Transmission
Saccharomyces cerevisiae
Ultraviolet Rays
description The aim of this study was to analyze the effectiveness of UV-C light (0–10.6 kJ/m2) assisted by mild heat treatment (50 °C) on the inactivation of Saccharomyces cerevisiae KE 162 in peptone water and fresh carrot-orange juice blend (pH: 3.8; 9.8°Brix; 707 NTU; absorption coefficient: 0.17 cm−1). Yeast induced damage by single UV-C and mild heat (H) and the combined treatment UV-C/H, was investigated by flow cytometry (FC) and transmission electron microscopy (TEM). When studying induced damage by FC, cells were labeled with fluorescein diacetate (FDA) and propidium iodide (PI) to monitor membrane integrity and esterase activity. UV-C/H provoked up to 4.7 log-reductions of S. cerevisiae; whereas, only 2.6–3.3 log-reductions were achieved by single UV-C and H treatments. FC revealed a shift with treatment time from cells with esterase activity and intact membrane to cells with permeabilized membrane. This shift was more noticeable in peptone water and UV-C/H treated juice. In the UV-C treated juice, double stained cells were detected, suggesting the possibility of being sub-lethally damaged, with compromised membrane but still metabolically active. TEM images of treated cells revealed severe damage, encompassing coagulated inner content, disorganized lumen and cell debris. FC and TEM provided additional information regarding degree and type of damage, complementing information revealed by the traditional plate count technique. © 2018 Elsevier Ltd
title Effectiveness of UV-C light assisted by mild heat on Saccharomyces cerevisiae KE 162 inactivation in carrot-orange juice blend studied by flow cytometry and transmission electron microscopy
title_short Effectiveness of UV-C light assisted by mild heat on Saccharomyces cerevisiae KE 162 inactivation in carrot-orange juice blend studied by flow cytometry and transmission electron microscopy
title_full Effectiveness of UV-C light assisted by mild heat on Saccharomyces cerevisiae KE 162 inactivation in carrot-orange juice blend studied by flow cytometry and transmission electron microscopy
title_fullStr Effectiveness of UV-C light assisted by mild heat on Saccharomyces cerevisiae KE 162 inactivation in carrot-orange juice blend studied by flow cytometry and transmission electron microscopy
title_full_unstemmed Effectiveness of UV-C light assisted by mild heat on Saccharomyces cerevisiae KE 162 inactivation in carrot-orange juice blend studied by flow cytometry and transmission electron microscopy
title_sort effectiveness of uv-c light assisted by mild heat on saccharomyces cerevisiae ke 162 inactivation in carrot-orange juice blend studied by flow cytometry and transmission electron microscopy
publishDate 2018
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_07400020_v73_n_p1_GarciaCarrillo
http://hdl.handle.net/20.500.12110/paper_07400020_v73_n_p1_GarciaCarrillo
_version_ 1840325814175924224