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Gędas A, Schmidt H, Weiss A. Identification and evaluation of Escherichia coli strain ATCC 8739 as a surrogate for thermal inactivation of enterohemorrhagic Escherichia coli in fruit nectars: Impact of applied techniques on the decimal reduction time. Food Microbiol 2024; 122:104544. [PMID: 38839230 DOI: 10.1016/j.fm.2024.104544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 04/12/2024] [Accepted: 04/13/2024] [Indexed: 06/07/2024]
Abstract
The objective of this study was to identify a suitable surrogate for E. coli O157:H7 strain 19685/91 and O113:H21 strain TS18/08, by assessing their thermal resistance at temperatures of 60 °C, 65 °C, and 72 °C in strawberry nectar. The influence of the matrix and the research methodology on the decimal reduction time (D-value) was investigated. Thermal kinetics and safety assessment demonstrated that E. coli ATCC 8739 is a suitable surrogate. The study demonstrated that the presence of fruit particles in the nectar increased thermal resistance of the tested strains. Variations in D-values were observed depending on the research method employed, with D-values in glass capillaries were up to 6.6 times lower compared to larger sample volumes. Encapsulation of E. coli ATCC 8739 exhibited high efficiency of 90.25 ± 0.26% and maintained stable viable counts after 26 days of storage in strawberry nectar at 4 °C. There were no significant differences in thermal resistance between surrogates directly inoculated into strawberry nectar and those encapsulated in alginate beads. Additionally, the encapsulated strains did not migrate outside the beads. Therefore, encapsulated E. coli ATCC 8739 in alginate beads can be effectively utilized in industrial settings to validate thermal treatments as a reliable and safe method.
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Affiliation(s)
- Astrid Gędas
- Food Microbiology, Hamburg School of Food Science, University of Hamburg, Ohnhorststrasse 18, 22609, Hamburg, Germany; Department of Food Microbiology and Hygiene, Institute of Food Science and Biotechnology, University of Hohenheim, Garbenstrasse 28, 70599, Stuttgart, Germany
| | - Herbert Schmidt
- Department of Food Microbiology and Hygiene, Institute of Food Science and Biotechnology, University of Hohenheim, Garbenstrasse 28, 70599, Stuttgart, Germany
| | - Agnes Weiss
- Food Microbiology, Hamburg School of Food Science, University of Hamburg, Ohnhorststrasse 18, 22609, Hamburg, Germany.
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2
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Gavriil A, Giannenas I, Skandamis PN. A current insight into Salmonella's inducible acid resistance. Crit Rev Food Sci Nutr 2024:1-21. [PMID: 39014992 DOI: 10.1080/10408398.2024.2373387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2024]
Abstract
Salmonella is a diverse and ubiquitous group of bacteria and a major zoonotic pathogen implicated in several foodborne disease outbreaks worldwide. With more than 2500 distinct serotypes, this pathogen has evolved to survive in a wide spectrum of environments and across multiple hosts. The primary and most common source of transmission is through contaminated food or water. Although the main sources have been primarily linked to animal-related food products, outbreaks due to the consumption of contaminated plant-related food products have increased in the last few years. The perceived ability of Salmonella to trigger defensive mechanisms following pre-exposure to sublethal acid conditions, namely acid adaptation, has renewed a decade-long attention. The impact of acid adaptation on the subsequent resistance against lethal factors of the same or multiple stresses has been underscored by multiple studies. Α plethora of studies have been published, aiming to outline the factors that- alone or in combination- can impact this phenomenon and to unravel the complex networking mechanisms underlying its induction. This review aims to provide a current and updated insight into the factors and mechanisms that rule this phenomenon.
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Affiliation(s)
- Alkmini Gavriil
- Department of Natural Resources Management and Agricultural Engineering, Agricultural University of Athens, Athens, Greece
- Department of Food Science and Human Nutrition, Agricultural University of Athens, Athens, Greece
| | - Ilias Giannenas
- School of Veterinary Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Panagiotis N Skandamis
- Department of Food Science and Human Nutrition, Agricultural University of Athens, Athens, Greece
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Özcan S, Işık S, Işık H, Güner S, Topalcengiz Z. Use of dishwashers fails to inactivate foodborne pathogens in home-canned model foods. Int J Food Microbiol 2024; 418:110739. [PMID: 38749263 DOI: 10.1016/j.ijfoodmicro.2024.110739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 03/15/2024] [Accepted: 05/06/2024] [Indexed: 05/27/2024]
Abstract
Risky home canning techniques are still performed for food preservation due to limited science-based recommendations. This study aimed to evaluate the inactivation of Shiga toxin-producing Escherichia coli O157:H7, Salmonella enterica (ser. Typhimurium, Enteritidis, and Infantis) and Listeria monocytogenes during home canning with a household dishwasher. The 450 mL of blended tomato (acidic liquid food) and potato puree (non-acidic solid food) were prepared with 1.5 % salt and 25 mL vinegar as model foods in glass jars (660 mL). The two model foods were sterilized, then inoculated with separate cocktails of each pathogen at 106-107 CFU/g. The prepared jars were placed in the bottom rack of a dishwasher and subjected to the following cycles: economic (50 °C, 122 min), express (60 °C, 54 min), and intensive (70 °C, 96 min). Temperature changes in jars were monitored by using thermocouples during heat treatment. Within the center of the jars, temperatures were measured as 45 to 53 °C in blended tomato and 44 to 52 °C in potato puree during all tested dishwasher cycles, respectively. The economic cycle treatment reduced S. enterica, E. coli O157:H7, and L. monocytogenes populations by 3.1, 4.6, and 4.2 log CFU/g in blended tomato (P ≤ 0.05), where a <1.0 log reduction was observed in potato puree (P > 0.05). All pathogens showed similar heat resistance during the express cycle treatment with a log reduction ranging from 4.2 to 5.0 log CFU/g in blended tomato and 0.6 to 0.7 log CFU/g in potato puree. Reduction in L. monocytogenes population was limited (0.6 log CFU/g) compared to E. coli O157:H7 (2.0 log CFU/g) and S. enterica (2.7 log CFU/g) in blended tomato during the intensive cycle treatment (P ≤ 0.05). Dishwasher cycles at manufacturer defined settings failed to adequately inactivate foodborne pathogens in model foods. This study indicates that home-canned vegetables may cause foodborne illnesses when dishwashers in home kitchens are used for heat processing.
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Affiliation(s)
- Seracettin Özcan
- Department of Food Safety, Graduate School of Natural and Applied Sciences, Muş Alparslan University, 49250 Muş, Türkiye
| | - Sefa Işık
- Department of Food Processing, Vocational School of Technical Sciences, Muş Alparslan University, 49250 Muş, Türkiye
| | - Hasan Işık
- Department of Food Processing, Vocational School of Technical Sciences, Muş Alparslan University, 49250 Muş, Türkiye
| | - Senem Güner
- Department of Food Engineering, Faculty of Engineering, Afyon Kocatepe University, 03200 Afyonkarahisar, Türkiye
| | - Zeynal Topalcengiz
- Department of Food Engineering, Faculty of Engineering and Architecture, Muş Alparslan University, 49250 Muş, Türkiye; Department of Food Science, Center for Food Safety, University of Arkansas System Division of Agriculture, Fayetteville, AR 72704, USA.
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Jung J, Harris LJ. Survival of Salmonella and Shiga toxin–producing Escherichia coli during tempering of wheat berries. Food Control 2023. [DOI: 10.1016/j.foodcont.2022.109343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Combined Effect of Ultrasound and Microwave Power in Tangerine Juice Processing: Bioactive Compounds, Amino Acids, Minerals, and Pathogens. Processes (Basel) 2022. [DOI: 10.3390/pr10102100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The inhibition of Escherichia coli ATCC 25922 (E. coli), Staphylococcus aureus ATCC6538 (S. aureus), Salmonella Enteritidis ATCC 13076 (S. Enteritidis), and Listeria monocytogenes DSM12464 (L. monocytogenes) is one of the main aims of the food industry. This study was the first in which the use of ultrasound and microwave power were applied to optimize the values of the bioactive components, amino acids, and mineral compositions of tangerine juice and to inhibit Escherichia coli, Staphylococcus aureus, Salmonella Enteritidis, and Listeria monocytogenes. The response surface methodology (RSM) was used to describe the inactivation kinetics, and the effects of ultrasound treatment time (X1: 12–20 min), ultrasound amplitude (X2:60–100%), microwave treatment time (X3: 30–40 s), and microwave power (X4:200–700 W). The optimum parameters applied to a 5-log reduction in E. coli were determined as ultrasound (12 min, 60%) and microwave (34 s, 700 W). The optimum condition ultrasound–microwave treatment was highly effective in tangerine juice, achieving up to 5.27, 5.12, and 7.19 log reductions for S. aureus, S. Enteritidis, and L. monocytogenes, respectively. Ultrasound–microwave treatment increased the total phenolic compounds and total amino acids. While Cu, K, Mg, and Na contents were increased, Fe and Ca contents were lower in the UM-TJ (ultrasound–microwave-treated tangerine juice) sample. In this case, significant differences were detected in the color values of ultrasound–microwave-treated tangerine juice (UM-TJ) (p < 0.05). The results of this study showed that ultrasound–microwave treatment is a potential alternative processing and preservation technique for tangerine juice, resulting in no significant quality depreciation.
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Effect of Hurdle Approaches Using Conventional and Moderate Thermal Processing Technologies for Microbial Inactivation in Fruit and Vegetable Products. Foods 2022; 11:foods11121811. [PMID: 35742009 PMCID: PMC9222969 DOI: 10.3390/foods11121811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 06/13/2022] [Accepted: 06/16/2022] [Indexed: 12/04/2022] Open
Abstract
Thermal processing of packaged fruit and vegetable products is targeted at eliminating microbial contaminants (related to spoilage or pathogenicity) and extending shelf life using microbial inactivation or/and by reducing enzymatic activity in the food. The conventional process of thermal processing involves sterilization (canning and retorting) and pasteurization. The parameters used to design the thermal processing regime depend on the time (minutes) required to eliminate a known population of bacteria in a given food matrix under specified conditions. However, due to the effect of thermal exposure on the sensitive nutrients such as vitamins or bioactive compounds present in fruits and vegetables, alternative technologies and their combinations are required to minimize nutrient loss. The novel moderate thermal regimes aim to eliminate bacterial contaminants while retaining nutritional quality. This review focuses on the “thermal” processing regimes for fruit and vegetable products, including conventional sterilization and pasteurization as well as mild to moderate thermal techniques such as pressure-assisted thermal sterilization (PATS), microwave-assisted thermal sterilization (MATS) and pulsed electric field (PEF) in combination with thermal treatment as a hurdle approach or a combined regime.
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Wang X, Tian S, Wu Y, Li H, Bai LI, Liu H, Zhang X, Dong Q. Strain Variability in Growth and Thermal Inactivation Characteristics of Listeria monocytogenes Strains after Acid Adaptation. J Food Prot 2021; 84:2229-2236. [PMID: 34197590 DOI: 10.4315/jfp-20-387] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 06/24/2021] [Indexed: 11/11/2022]
Abstract
ABSTRACT Given the importance of strain variability to predictive microbiology and risk assessment, this study aimed to quantify the magnitude of strain variability in growth and thermal inactivation kinetics behaviors after acid adaptation. Thirty-three Listeria monocytogenes strains were exposed to acid-adapted tryptic soy broth supplemented with yeast extract (TSBYE; pH 5.5) and non-acid-adapted TSBYE (pH 7.0) for 20 h. Next, the growth parameters of these adapted and nonadapted strains that grew in nonbuffered TSBYE at 25°C were estimated. The tested strains were inactivated at 60°C in nonbuffered broth to obtain the heat resistance parameters. The results revealed that strain variability was present in the growth and thermal inactivation characteristics. The maximum specific growth rate ranged from 0.21 to 0.44 h-1 and from 0.20 to 0.45 h-1 after acid and nonacid adaptation, respectively. The lag times were from 0.69 to 2.56 h and from 0.24 to 3.36 h for acid-adapted and non-acid-adapted cells, respectively. The apparent D-values at 60°C of the pathogen ranged between 0.56 and 3.93 min and between 0.52 and 3.63 min for the presence and absence of acid adaptation condition, respectively. Acid adaptation significantly (P < 0.05) increased the magnitude of strain variability in the thermal inactivation characteristics of L. monocytogenes, with the coefficient of variation increasing to 0.17, whereas acid adaptation did not significantly (P ≥ 0.05) influence the variabilities in the growth parameters of the tested strains. Furthermore, the subsequent growth behaviors of all strains did not exhibit significant (P > 0.05) changes after exposure to acidic broth. However, the thermal resistance of most (25 of 33) of the tested strains increased (P < 0.05) after growing in acid-adapted broth. The relevant data generated in the present study can be used to describe the strain variability in predictive microbiology and to deeply understand the behavioral responses of different strains to acid adaptation. HIGHLIGHTS
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Affiliation(s)
- Xiang Wang
- School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, People's Republic of China
| | - Shihong Tian
- School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, People's Republic of China
| | - Yufan Wu
- Technology Center of Zhangjiagang Customs, Jiangsu 310012, People's Republic of China
| | - Hongmei Li
- School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, People's Republic of China
| | - L I Bai
- China National Center for Food Safety Risk Assessment, Beijing 100021, People's Republic of China
| | - Hong Liu
- Shanghai Municipal Center for Disease Control & Prevention, Shanghai 200336, People's Republic of China
| | - Xibin Zhang
- New Hope Liuhe Co., Ltd., Beijing 100102, People's Republic of China
| | - Qingli Dong
- School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, People's Republic of China
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He Y, Chen R, Qi Y, Salazar JK, Zhang S, Tortorello ML, Deng X, Zhang W. Survival and transcriptomic response of Salmonella enterica on fresh-cut fruits. Int J Food Microbiol 2021; 348:109201. [PMID: 33930836 DOI: 10.1016/j.ijfoodmicro.2021.109201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Revised: 03/26/2021] [Accepted: 04/13/2021] [Indexed: 01/21/2023]
Abstract
Salmonella enterica is frequently implicated in foodborne disease outbreaks associated with fresh-cut fruits. In the U.S., more than one third of fruit-related outbreaks have been linked to two S. enterica serotypes Newport and Typhimurium. Approximately 80% of fruit-related human salmonellosis cases were associated with tomatoes, cantaloupes and cucumbers. In this study, we investigated the population dynamics of S. Newport and S. Typhimurium on fresh-cut tomato, cantaloupe, cucumber and apple under short-term storage conditions. We further compared the transcriptomic profiles of a S. Newport strain on fresh-cut tomato and cantaloupe using high-throughput RNA-seq. We demonstrated that both S. enterica Newport and Typhimurium survived well on various fresh-cut fruit items under refrigeration storage conditions, independent of inoculation levels. However, S. enterica displayed variable survival behaviors on different types of fruits. For example, at 7 d storage, the population of S. enterica reduced less than 0.2 log (p > 0.05) on fresh-cut tomato and cantaloupe, in contrast to ~0.5 log (p < 0.05) on cucumber and apple. RNA-seq analysis suggested that S. enterica mediates its survival on fresh-cut fruits through differentially regulating genes involved in specific carbon utilization and metabolic pathways. Several known bacterial virulence factors (e.g., pag gene) were found to be differentially regulated on fresh-cut tomato and cantaloupe, suggesting a link between the events of food contamination and subsequent human infection. Findings from this study contribute to a better understanding of S. enterica survival mechanisms on fresh-cut produce.
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Affiliation(s)
- Yingshu He
- Department of Food Science and Nutrition & Institute for Food Safety and Health, Illinois Institute of Technology, Bedford Park, IL, USA; Center for Food Safety, College of Agricultural and Environmental Sciences, University of Georgia, Griffin, GA, USA.
| | - Ruixi Chen
- Department of Food Science and Nutrition & Institute for Food Safety and Health, Illinois Institute of Technology, Bedford Park, IL, USA
| | - Yan Qi
- Center for Food Safety, College of Agricultural and Environmental Sciences, University of Georgia, Griffin, GA, USA
| | - Joelle K Salazar
- Division of Food Processing Science and Technology, U. S. Food and Drug Administration, Bedford Park, IL, USA
| | - Shimei Zhang
- Department of Food Science and Nutrition & Institute for Food Safety and Health, Illinois Institute of Technology, Bedford Park, IL, USA
| | - Mary Lou Tortorello
- Division of Food Processing Science and Technology, U. S. Food and Drug Administration, Bedford Park, IL, USA
| | - Xiangyu Deng
- Center for Food Safety, College of Agricultural and Environmental Sciences, University of Georgia, Griffin, GA, USA
| | - Wei Zhang
- Department of Food Science and Nutrition & Institute for Food Safety and Health, Illinois Institute of Technology, Bedford Park, IL, USA
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Muhialdin BJ, Kadum H, Meor Hussin AS. Metabolomics profiling of fermented cantaloupe juice and the potential application to extend the shelf life of fresh cantaloupe juice for six months at 8 °C. Food Control 2021. [DOI: 10.1016/j.foodcont.2020.107555] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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10
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Acuff JC, Waterman K, Ramakrishnan J, Ponder MA. Thermal Resistance of Single Strains of Shiga Toxin-Producing Escherichia coli O121:H19 and O157:H7 Based on Culture Preparation Method and Osmolyte-Reduced Water Activity. J Food Prot 2021; 84:122-127. [PMID: 32916717 DOI: 10.4315/jfp-20-122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 09/05/2020] [Indexed: 11/11/2022]
Abstract
ABSTRACT Bacterial exposure to stress, such as reduced water activity (aw), can increase thermal resistance. Pathogen thermal resistance studies on low-aw foods use a variety of methods to inoculate food, as well as strategies to reduce aw, which can influence observations. This study investigated effects of culture preparation method and osmolyte-induced aw on thermal resistance of two Shiga toxin-producing Escherichia coli (STEC) strains (O121:H19 and O157:H7) challenged with isothermal conditions, determining D- and z-values for each isolate (56, 59, and 62°C). Tryptic soy broth (TSB) and agar (lawn cultures) were compared. D-values of broth cultures were significantly and consistently larger than those of lawn cultures, and O121 was significantly more resistant than O157, but only at 56°C (P < 0.05). To compare potential effects of aw on STEC thermal resistance, cells were suspended in osmolyte solutions with varying aw: high (TSB, aw 0.99), intermediate (61% glycerol or 26% NaCl, aw 0.75), and low (82% glycerol, aw 0.5). In most instances, STEC strains in high-aw broth exhibited greater heat resistance compared to reduced-aw solutions, with the exception of the glycerol intermediate-aw solution (aw 0.75). Magnitudes varied with strain and temperature. The z-values of lawn cultures were significantly lower than those of broth cultures (P < 0.05), but there were few differences between high-aw and reduced-aw samples. There were no significant differences of z-values based on strain type. These results highlight that thermal resistance can be affected by culture preparation and that osmolyte-induced changes to aw influence thermal inactivation of STEC by varying magnitudes. These results emphasize the challenges of extrapolating results from laboratory inactivation kinetic experiments to determine the inactivation of low-aw foods, especially those considered dry in nature. HIGHLIGHTS
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Affiliation(s)
- Jennifer C Acuff
- Department of Food Science and Technology, Virginia Tech, 1230 Washington Street, Blacksburg, Virginia 24061, USA
| | - Kim Waterman
- Department of Food Science and Technology, Virginia Tech, 1230 Washington Street, Blacksburg, Virginia 24061, USA
| | - Jahnavi Ramakrishnan
- Department of Food Science and Technology, Virginia Tech, 1230 Washington Street, Blacksburg, Virginia 24061, USA
| | - Monica A Ponder
- Department of Food Science and Technology, Virginia Tech, 1230 Washington Street, Blacksburg, Virginia 24061, USA.,(ORCID: https://orcid.org/0000-0001-7047-3127 [M.A.P.])
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Kang JW, Kim WJ, Kang DH. Synergistic effect of 222-nm krypton-chlorine excilamp and mild heating combined treatment on inactivation of Escherichia coli O157:H7 and Salmonella Typhimurium in apple juice. Int J Food Microbiol 2020; 329:108665. [PMID: 32497789 DOI: 10.1016/j.ijfoodmicro.2020.108665] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 03/20/2020] [Accepted: 05/16/2020] [Indexed: 10/24/2022]
Abstract
Simultaneous treatment with 222-nm KrCl excilamp and mild heating (EX-MH) at 45, 50 and 55 °C showed synergistic bactericidal effects on non-acid and acid adapted cells of Escherichia coli O157:H7 and Salmonella Typhimurium in apple juice. In particular, acid-adapted pathogens exhibited increased resistance to EX-MH compared to pathogenic bacteria that were not acid-adapted. Also, elucidation of the synergistic bactericidal mechanism of EX-MH was performed through several assays and this mechanism was described as follows: (i) when KrCl excilamp (EX) and mild heating (MH) are applied simultaneously, MH reversibly inactivates the antioxidant enzyme, superoxide dismutase (SOD), thereby increasing accumulation of reactive oxygen species (ROS) generated by EX and thus inducing synergistic ROS generation, (ii) ROS production induces lipid peroxidation occurrence in the cell membrane, (iii) this lipid peroxidation occurrence in the cell membrane induces synergistic destruction of cell membrane, resulting in synergistic cell death. While EX-MH of 45, 50, or 55 °C reduced E. coli O157:H7 (the pathogen most resistant to EX-MH) in apple juice by 5-log, the qualities such as color (L*, a*, and b*), total phenolic compounds (TPC), and DPPH free radical scavenging activity of apple juice did not change significantly (P > 0.05). This study not only suggests the applicability of EX-MH to the apple juice industry, but also can be used as baseline data for future relevant research.
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Affiliation(s)
- Jun-Won Kang
- Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, Center for Food and Bioconvergence, Research Institute for Agricultural and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Woo-Ju Kim
- Department of Food Science and Technology, The Ohio State University, 2015 Fyffe road, Columbus, OH 43210, USA
| | - Dong-Hyun Kang
- Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, Center for Food and Bioconvergence, Research Institute for Agricultural and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea; Institutes of Green Bio Science & Technology, Seoul National University, Pyeongchang-gun, Gangwon-do 25354, Republic of Korea.
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12
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Screening for heat-resistant reference yeast isolate in orange juice. Food Microbiol 2020; 94:103639. [PMID: 33279065 DOI: 10.1016/j.fm.2020.103639] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 08/25/2020] [Accepted: 08/29/2020] [Indexed: 11/23/2022]
Abstract
This study details a screening process for yeast species that may be used as reference microorganisms for mild thermal processing of orange juice. In the initial step, 17 different strains of spoilage yeasts with similar initial populations (6.0-7.0 log CFU/mL) and growth stage (middle stationary phase) were subjected to equal heating process (55 °C, 5 min) in Yeast Peptone Glucose Broth (pH 6.06). The change in populations observed ranged from 3.33 log CFU/mL (Pichia fermentans BFE-38) to 6.53 log CFU/mL (Torulaspora delbrueckii BFE-37). In the second step of the screening, 6 of the most resistant strains were further challenged in an orange juice suspending medium (pH 3.88, 10.02 °Brix, 0.82% citric acid) at different heating temperatures (50, 53, 55, 57, and 60 °C). The decimal reduction times (DT values) and thermal resistant constants (z values) were determined. Results showed that all tested yeasts exhibited first-order, log-linear inactivation behavior (R2 0.90-0.99). As expected, significant (P < 0.05) reduction in the DT values were observed with increasing temperature. P. fermentans BFE-38 exhibited the greatest Dvalues at 50-55 °C. However, the test isolate with the greatest z-value was found to be P. anomala (BIOTECH 2205).
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13
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Topalcengiz Z. Assessment of recommended thermal inactivation parameters for fruit juices. Lebensm Wiss Technol 2019. [DOI: 10.1016/j.lwt.2019.108475] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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14
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Prior physicochemical stress exposures and subsequent UV-C resistance of E. coli O157:H7 in coconut liquid endosperm. FOOD AND BIOPRODUCTS PROCESSING 2019. [DOI: 10.1016/j.fbp.2019.06.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Gurtler JB, Fan X, Jin T, Niemira BA. Influence of Antimicrobial Agents on the Thermal Sensitivity of Foodborne Pathogens: A Review. J Food Prot 2019; 82:628-644. [PMID: 30917037 DOI: 10.4315/0362-028x.jfp-18-441] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
HIGHLIGHTS Consumers are demanding more natural and organic foods and ingredients. Many additives alone are insufficient to inactivate pathogens or prevent growth. Mild heat combined with antimicrobial agents synergistically inactivate pathogens. Here we review studies using thermally assisted antimicrobial inactivation. Many opportunities exist for the application of this hurdle technology in foods.
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Affiliation(s)
- Joshua B Gurtler
- U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 East Mermaid Lane, Wyndmoor, Pennsylvania 19038, USA (ORCID: http://orcid.org/0000-0001-5844-7794 [J.B.G.])
| | - Xuetong Fan
- U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 East Mermaid Lane, Wyndmoor, Pennsylvania 19038, USA (ORCID: http://orcid.org/0000-0001-5844-7794 [J.B.G.])
| | - Tony Jin
- U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 East Mermaid Lane, Wyndmoor, Pennsylvania 19038, USA (ORCID: http://orcid.org/0000-0001-5844-7794 [J.B.G.])
| | - Brendan A Niemira
- U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 East Mermaid Lane, Wyndmoor, Pennsylvania 19038, USA (ORCID: http://orcid.org/0000-0001-5844-7794 [J.B.G.])
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Kang JW, Kang DH. Increased Resistance of Salmonella enterica Serovar Typhimurium and Escherichia coli O157:H7 to 222-Nanometer Krypton-Chlorine Excilamp Treatment by Acid Adaptation. Appl Environ Microbiol 2019; 85:e02221-18. [PMID: 30610077 PMCID: PMC6414383 DOI: 10.1128/aem.02221-18] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 12/24/2018] [Indexed: 11/20/2022] Open
Abstract
In this study, we examined the change in resistance of Salmonella enterica serovar Typhimurium and Escherichia coli O157:H7 to 222-nm krypton-chlorine (KrCl) excilamp treatment as influenced by acid adaptation and identified a mechanism of resistance change. In addition, we measured changes in apple juice quality indicators, such as color, total phenols, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity, during treatment. Non-acid-adapted and acid-adapted pathogens were induced by growing the cells in tryptic soy broth without dextrose (TSB w/o D) at pH 7.3 and in TSB w/o D at pH 5.0 (adjusted with HCl), respectively. For the KrCl excilamp treatment, acid-adapted pathogens exhibited significantly (P < 0.05) higher D5d values, which indicate dosages required to achieve a 5-log reduction, than those for non-acid-adapted pathogens in both commercially clarified apple juice and phosphate-buffered saline (PBS), and the pathogens in the juice showed significantly (P < 0.05) higher D5d values than those for pathogens in PBS because of the UV-absorbing characteristics of apple juice. Through mechanism identification, it was found that the generation of lipid peroxidation in the cell membrane, inducing cell membrane destruction, was significantly (P < 0.05) lower in acid-adapted cells than in non-acid-adapted cells for the same amount of reactive oxygen species (ROS) generated at the same dose because the ratio of unsaturated to saturated fatty acids (USFA/SFA) in the cell membrane was significantly (P < 0.05) decreased as a result of acid adaptation. Treated apple juice showed no significant (P > 0.05) difference in quality indicators compared to those of untreated controls during treatment at 1,773 mJ/cm2IMPORTANCE There is a need for novel, mercury-free UV lamp technology to replace germicidal lamps containing harmful mercury, which are routinely utilized for UV pasteurization of apple juice. In addition, consideration of the changes in response to antimicrobial treatments that may occur when pathogens are adapted to the acid in an apple juice matrix is critical to the practical application of this technology. Based on this, an investigation using 222-nm KrCl excilamp technology, an attractive alternative to mercury lamps, was conducted. Our study demonstrated increased resistance to 222-nm KrCl excilamp treatment as pathogens adapted to acids, and this was due to changes in reactivity to ROS with changes in the fatty acid composition of the cell membrane. Despite increased resistance, the 222-nm KrCl excilamp achieved pathogen reductions of 5 log or more at laboratory scale without affecting apple juice quality. These results provide valuable baseline data for application of 222-nm KrCl excilamps in the apple juice industry.
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Affiliation(s)
- Jun-Won Kang
- Department of Agricultural Biotechnology, Center for Food and Bioconvergence, Research Institute for Agricultural and Life Sciences, Seoul National University, Seoul, Republic of Korea
- Institutes of Green-bio Science & Technology, Seoul National University, Pyeongchang-gun, Gangwon-do, Republic of Korea
| | - Dong-Hyun Kang
- Department of Agricultural Biotechnology, Center for Food and Bioconvergence, Research Institute for Agricultural and Life Sciences, Seoul National University, Seoul, Republic of Korea
- Institutes of Green-bio Science & Technology, Seoul National University, Pyeongchang-gun, Gangwon-do, Republic of Korea
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Gabriel AA, Ancog MML. Effects of suboptimal growth conditions on the subsequent UV-C resistance of Listeria monocytogenes in coconut liquid endosperm and apple juice. Lebensm Wiss Technol 2019. [DOI: 10.1016/j.lwt.2018.10.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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18
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Ukuku DO, Mukhopadhyay S, Olanya M. Reducing Transfer of Salmonella and Aerobic Mesophilic Bacteria on Melon Rinds Surfaces to Fresh Juice by Washing With Chlorine: Effect of Waiting Period Before Refrigeration of Prepared Juice. FRONTIERS IN SUSTAINABLE FOOD SYSTEMS 2018. [DOI: 10.3389/fsufs.2018.00078] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Kang IB, Kim DH, Jeong D, Park JH, Seo KH. Heat resistance of Salmonella Enteritidis under prolonged exposure to acid-salt combined stress and subsequent refrigeration. Int J Food Microbiol 2018; 285:165-172. [DOI: 10.1016/j.ijfoodmicro.2018.08.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 06/25/2018] [Accepted: 08/12/2018] [Indexed: 01/11/2023]
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Gabriel AA, Ostonal JM, Cristobal JO, Pagal GA, Armada JVE. Individual and combined efficacies of mild heat and ultraviolet-c radiation against Escherichia coli O157:H7, Salmonella enterica , and Listeria monocytogenes in coconut liquid endosperm. Int J Food Microbiol 2018; 277:64-73. [DOI: 10.1016/j.ijfoodmicro.2018.04.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 02/16/2018] [Accepted: 04/10/2018] [Indexed: 10/17/2022]
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21
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Effect of storage conditions in the response of Listeria monocytogenes in a fresh purple vegetable smoothie compared with an acidified TSB medium. Food Microbiol 2018; 72:98-105. [DOI: 10.1016/j.fm.2017.11.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 10/29/2017] [Accepted: 11/11/2017] [Indexed: 11/23/2022]
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22
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Daryaei H, Peñaloza W, Hildebrandt I, Krishnamurthy K, Thiruvengadam P, Wan J. Heat inactivation of Shiga toxin-producing Escherichia coli in a selection of low moisture foods. Food Control 2018. [DOI: 10.1016/j.foodcont.2017.08.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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23
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Timmermans R, Mastwijk H, Nierop Groot M, Van Boekel M. Evaluation of the Gauss-Eyring model to predict thermal inactivation of micro-organisms at short holding times. Int J Food Microbiol 2017; 263:47-60. [DOI: 10.1016/j.ijfoodmicro.2017.10.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 08/23/2017] [Accepted: 10/01/2017] [Indexed: 11/24/2022]
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24
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Estilo EEC, Gabriel AA. Previous stress exposures influence subsequent UV-C resistance of Salmonella enterica in coconut liquid endosperm. Lebensm Wiss Technol 2017. [DOI: 10.1016/j.lwt.2017.07.061] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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25
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Tchuenchieu A, Sylvain SK, Pop C, Jean‐Justin EN, Mudura E, Etoa F, Rotar A. Low thermal inactivation of
Escherichia coli
ATCC 25922 in pineapple, orange and watermelon juices: Effect of a prior acid‐adaptation and of carvacrol supplementation. J Food Saf 2017. [DOI: 10.1111/jfs.12415] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Alex Tchuenchieu
- Department of MicrobiologyFaculty of Science, University of Yaoundé IYaoundé Cameroon
- Faculty of Food Science and TechnologyUniversity of Agricultural Science and Veterinary, MedicineCluj‐Napoca Romania
- Centre for Food and Nutrition Research, IMPMYaoundé Cameroon
| | - Sado Kamdem Sylvain
- Department of MicrobiologyFaculty of Science, University of Yaoundé IYaoundé Cameroon
| | - Carmen Pop
- Faculty of Food Science and TechnologyUniversity of Agricultural Science and Veterinary, MedicineCluj‐Napoca Romania
| | | | - Elena Mudura
- Faculty of Food Science and TechnologyUniversity of Agricultural Science and Veterinary, MedicineCluj‐Napoca Romania
| | - François‐Xavier Etoa
- Department of MicrobiologyFaculty of Science, University of Yaoundé IYaoundé Cameroon
| | - Ancuta Rotar
- Faculty of Food Science and TechnologyUniversity of Agricultural Science and Veterinary, MedicineCluj‐Napoca Romania
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Topalcengiz Z, Danyluk MD. Thermal inactivation responses of acid adapted and non-adapted stationary phase Shiga toxin-producing Escherichia coli (STEC), Salmonella spp. and Listeria monocytogenes in orange juice. Food Control 2017. [DOI: 10.1016/j.foodcont.2016.07.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Haberbeck LU, Wang X, Michiels C, Devlieghere F, Uyttendaele M, Geeraerd AH. Cross-protection between controlled acid-adaptation and thermal inactivation for 48 Escherichia coli strains. Int J Food Microbiol 2017; 241:206-214. [DOI: 10.1016/j.ijfoodmicro.2016.10.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 09/02/2016] [Accepted: 10/08/2016] [Indexed: 11/26/2022]
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Li H, Gänzle M. Some Like It Hot: Heat Resistance of Escherichia coli in Food. Front Microbiol 2016; 7:1763. [PMID: 27857712 PMCID: PMC5093140 DOI: 10.3389/fmicb.2016.01763] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 10/20/2016] [Indexed: 11/13/2022] Open
Abstract
Heat treatment and cooking are common interventions for reducing the numbers of vegetative cells and eliminating pathogenic microorganisms in food. Current cooking method requires the internal temperature of beef patties to reach 71°C. However, some pathogenic Escherichia coli such as the beef isolate E. coli AW 1.7 are extremely heat resistant, questioning its inactivation by current heat interventions in beef processing. To optimize the conditions of heat treatment for effective decontaminations of pathogenic E. coli strains, sufficient estimations, and explanations are necessary on mechanisms of heat resistance of target strains. The heat resistance of E. coli depends on the variability of strains and properties of food formulations including salt and water activity. Heat induces alterations of E. coli cells including membrane, cytoplasm, ribosome and DNA, particularly on proteins including protein misfolding and aggregations. Resistant systems of E. coli act against these alterations, mainly through gene regulations of heat response including EvgA, heat shock proteins, σE and σS, to re-fold of misfolded proteins, and achieve antagonism to heat stress. Heat resistance can also be increased by expression of key proteins of membrane and stabilization of membrane fluidity. In addition to the contributions of the outer membrane porin NmpC and overcome of osmotic stress from compatible solutes, the new identified genomic island locus of heat resistant performs a critical role to these highly heat resistant strains. This review aims to provide an overview of current knowledge on heat resistance of E. coli, to better understand its related mechanisms and explore more effective applications of heat interventions in food industry.
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Affiliation(s)
- Hui Li
- Department of Agricultural, Food and Nutritional Science, University of Alberta, EdmontonAB, Canada
| | - Michael Gänzle
- Department of Agricultural, Food and Nutritional Science, University of Alberta, EdmontonAB, Canada
- College of Bioengineering and Food Science, Hubei University of TechnologyHubei, China
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The Acid Tolerance Response Alters Membrane Fluidity and Induces Nisin Resistance in Listeria monocytogenes. Probiotics Antimicrob Proteins 2016; 1:130-5. [PMID: 26783167 DOI: 10.1007/s12602-009-9025-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
The ability of L. monocytogenes cells to adapt to a variety of stressors contributes to its growth in a wide range of foods. The present study examines the effect of acid and of the acid tolerance response (ATR) on membrane fluidity and on the organism's resistance to acid and to the bacteriocin nisin. When ATR was induced in wild-type cells, these cells also became resistant to nisin. ATR(+) cells also had lower membrane rigidities than control ATR(-) cells that had not been subjected to the acid tolerance response. However, cells that were genetically resistant to nisin did not show any significant (P < 0.05) change in rigidity when grown in the presence of nisin. These studies suggest that the use of acid and nisin for L. monocytogenes control in ready-to-eat foods may be compromised if cross-resistance emerges.
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Gabriel AA, Albura MP, Faustino KC. Thermal death times of acid-habituated Escherichia coli and Salmonella enterica in selected fruit beverages. Food Control 2015. [DOI: 10.1016/j.foodcont.2015.03.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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31
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Previous physicochemical stress exposures influence subsequent resistance of Escherichia coli O157:H7, Salmonella enterica, and Listeria monocytogenes to ultraviolet-C in coconut liquid endosperm beverage. Int J Food Microbiol 2015; 201:7-16. [DOI: 10.1016/j.ijfoodmicro.2015.02.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 01/29/2015] [Accepted: 02/02/2015] [Indexed: 12/30/2022]
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Affiliation(s)
- Máire Begley
- Department of Biological Sciences, Cork Institute of Technology, Bishopstown, Cork, Ireland;
| | - Colin Hill
- School of Microbiology and Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland;
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33
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Gabriel AA. Inactivation behaviors of foodborne microorganisms in multi-frequency power ultrasound-treated orange juice. Food Control 2014. [DOI: 10.1016/j.foodcont.2014.05.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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34
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Song WJ, Sung HJ, Kang DH. Inactivation of Escherichia coli O157:H7 and Salmonella Typhimurium in apple juices with different soluble solids content by combining ozone treatment with mild heat. J Appl Microbiol 2014; 118:112-22. [PMID: 25346257 DOI: 10.1111/jam.12671] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Revised: 09/16/2014] [Accepted: 10/16/2014] [Indexed: 11/26/2022]
Abstract
AIMS This study evaluated the combined effects of ozone and heat treatment to inactivate Escherichia coli O157:H7 and Salmonella Typhimurium in three types of apple juice of different soluble solids content. METHODS AND RESULTS Three types of apple juice (18, 36, 72 °Brix) inoculated with pathogens were subjected to ozone (3·0 l min(-1) flow rate and 2·0-3·0 g m(-3) concentration) and heat treatment (25, 45, 50 and 55°C) simultaneously for 20, 40 and 60 s. Initial populations of pathogens in inoculated apple juice were approximately 10(5)-10(6) CFU ml(-1). Heat treatment alone (25, 45, 50 and 55°C) for 1 min reduced populations of E. coli O157:H7 by 0 to 4·75 log CFU ml(-1) in three types of apple juice. The combination of ozone and heat treatment for 1 min at 25 and 45°C reduced E. coli O157:H7 by 0·93-3·87 log CFU ml(-1) and below the detection limit (>1 log CFU ml(-1)) at 50 and 55°C. A similar tendency was observed for S. Typhimurium. In several instances, results showed a synergistic effect of ozone and heat treatment. Colour values were not changed during ozone and heat treatment. CONCLUSION These results show that the combination of ozone and heat treatment can be used as a potential inactivation intervention for E. coli O157:H7 and S. Typhimurium in apple juice. SIGNIFICANCE AND IMPACT OF THE STUDY The combination of ozone treatment and mild heat can be used as an alternative intervention for pasteurization of varying soluble solids content apple juice in food industries.
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Affiliation(s)
- W-J Song
- Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, Center for Food and Bioconvergence, and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, Korea; Institutes of Green Bio Science & Technology, Seoul National University, Pyeongchang-gun, Gangwon-do, Korea
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Usaga J, Worobo RW, Padilla-Zakour OI. Effect of acid adaptation and acid shock on thermal tolerance and survival of Escherichia coli O157:H7 and O111 in apple juice. J Food Prot 2014; 77:1656-63. [PMID: 25285481 DOI: 10.4315/0362-028x.jfp-14-126] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Gradual exposure to moderate acidic environments may enhance the thermal tolerance and survival of Escherichia coli O157:H7 in acid and acidified foods. Limited studies comparing methodologies to induce this phenomenon have been performed. The effects of strain and physiological state on thermal tolerance and survival of E. coli in apple juice were studied. The decimal reduction time (D-value) at 56°C [D56°C] was determined for E. coli O157:H7 strains C7927 and ATCC 43895 and E. coli O111 at four physiological states: unadapted, acid-shocked (two methodologies used), and acid-adapted cells. The effect of acidulant was also evaluated by determining the D56°C for the O157:H7 strains subjected to acid shock during 18 h in Trypticase soy broth (TSB), with pH 5 adjusted with hydrochloric, lactic, and malic acids. Survival of the three strains at four physiological states was determined at 1 ± 1°C and 24 ± 2°C. Experiments were performed in triplicate. For thermal inactivation, a significant interaction was found between strain and physiological state (P < 0.0001). Highest thermal tolerance was observed for the 43895 strain subjected to acid shock during 18 h in TSB acidified with HCl (D56°C of 3.0 ± 0.1 min) and the lowest for the acid-shocked C7927 strain treated for 4 h in TSB acidified with HCl (D56°C of 0.45 ± 0.06 min). Acidulants did not alter the heat tolerance of strain C7927 (D56°C of 1.9 ± 0.1 min; P > 0.05) but significantly affected strain 43895 (P < 0.05), showing the greatest tolerance when malic acid was used (D56°C of 3.7 ± 0.3 min). A significant interaction between strain, storage temperature, and physiological state was noted during the survival experiments (P < 0.05). E. coli O111 was the most resistant strain, surviving 6 and 23 days at 24 and 1°C, respectively. Our findings may assist in designing challenge studies for juices and other pH-controlled products, where Shiga toxin-producing E. coli represents the pathogen of concern.
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Affiliation(s)
- Jessie Usaga
- Department of Food Science, Cornell University, 630 West North Street, Geneva, New York 14456, USA
| | - Randy W Worobo
- Department of Food Science, Cornell University, 630 West North Street, Geneva, New York 14456, USA
| | - Olga I Padilla-Zakour
- Department of Food Science, Cornell University, 630 West North Street, Geneva, New York 14456, USA.
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Listeria monocytogenes inactivation kinetics under microwave and conventional thermal processing in a kiwifruit puree. INNOV FOOD SCI EMERG 2014. [DOI: 10.1016/j.ifset.2014.01.005] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Usaga J, Worobo RW, Padilla-Zakour OI. Thermal resistance parameters of acid-adapted and unadapted Escherichia coli O157:H7 in apple-carrot juice blends: effect of organic acids and pH. J Food Prot 2014; 77:567-73. [PMID: 24680067 DOI: 10.4315/0362-028x.jfp-13-371] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Numerous outbreaks involving fresh juices contaminated with Escherichia coli O157:H7 have occurred in the United States and around the world, raising concern for the safety of these products. Until now, only a few studies regarding the thermal tolerance of this pathogen in acidic juices over a wide range of pH values have been published. Therefore, the effect of varying the pH with different organic acids on the thermal inactivation of non-acid-adapted and acid-adapted E. coli O157:H7 (strain C7927) was determined. The decimal reduction times (D-values) and the change in temperature required for the thermal destruction curve to traverse 1 log cycle (z-values) were calculated for non-acid-adapted E. coli in an apple-carrot juice blend (80:20) adjusted to three pH values (3.3, 3.5, and 3.7) by the addition of lactic, malic, or acetic acid and at a pH of 4.5 adjusted with NaOH. Thermal parameters were also determined for acid-adapted cells in juices acidified with malic acid. The effect of the soluble solids content on the thermal tolerance was studied in samples with a pH of 3.7 at 9.4 to 11.5 °Brix. The D-values were determined at 54, 56, and 58 °C, and trials were conducted in triplicate. Non-acid-adapted E. coli exhibited the highest thermal tolerance at pH 4.5 (D-value at 54 °C [D54 °C] of 20 ± 4 min and z-value of 6.2 °C), although on average, the D-values increased significantly (P < 0.01) due to acid adaptation. In acidified juices, the highest tolerance was observed in acid-adapted E. coli in samples adjusted to pH 3.7 with malic acid (D54 °C of 9 ± 2 min and z-value of 5.4 °C) and the lowest in unadapted E. coli at pH 3.3 acidified with acetic acid (D58 °C of 0.03 ± 0.01 min and z-value of 10.4 °C). For juices acidified to the same endpoint pH with different acids, E. coli was found to be more tolerant in samples acidified with malic acid, followed by lactic and acetic acids. Increasing the soluble solids content from 9.4 to 11.5 °Brix showed no significant effect on the thermal tolerance of E. coli (P > 0.01). The data from this study will be useful for establishing critical limits for safe thermal processing of pH-controlled juices and similar products.
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Affiliation(s)
- Jessie Usaga
- New York State Agricultural Experiment Station, Cornell University, Department of Food Science, 630 West North Street, Geneva, New York 14456, USA
| | - Randy W Worobo
- New York State Agricultural Experiment Station, Cornell University, Department of Food Science, 630 West North Street, Geneva, New York 14456, USA
| | - Olga I Padilla-Zakour
- New York State Agricultural Experiment Station, Cornell University, Department of Food Science, 630 West North Street, Geneva, New York 14456, USA.
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Pulsed electric field processing of different fruit juices: Impact of pH and temperature on inactivation of spoilage and pathogenic micro-organisms. Int J Food Microbiol 2014; 173:105-11. [DOI: 10.1016/j.ijfoodmicro.2013.12.022] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 12/23/2013] [Accepted: 12/23/2013] [Indexed: 11/23/2022]
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Gabriel AA, Arellano RU. Decimal reduction times of acid-adapted and non-adapted Escherichia coli O157:H7, Salmonella spp., and Listeria monocytogenes in young Cocos nucifera Linn. liquid endosperm. Food Control 2014. [DOI: 10.1016/j.foodcont.2013.08.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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40
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Youssef M, Yang X, Badoni M, Gill C. Survival of acid-adapted Escherichia coli O157:H7 and not-adapted E. coli on beef treated with 2% or 5% lactic acid. Food Control 2013. [DOI: 10.1016/j.foodcont.2013.03.037] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Vasan A, Leong WM, Ingham SC, Ingham BH. Thermal tolerance characteristics of non-O157 Shiga toxigenic strains of Escherichia coli (STEC) in a beef broth model system are similar to those of O157:H7 STEC. J Food Prot 2013; 76:1120-8. [PMID: 23834785 DOI: 10.4315/0362-028x.jfp-12-500] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The non-O157 Shiga toxigenic Escherichia coli (STEC) serogroups most commonly associated with illness are O26, O45, O103, O111, O121, and O145. In the United States, these serogroups are considered adulterants in raw nonintact beef. To begin to understand the behavior of these pathogens in meat systems, we compared the thermal tolerance of acid-adapted cells of non-O157 STEC and O157:H7 STEC in a beef-derived broth. D58°C-values were determined for at least three strains per serogroup, and D54.6°C-values and D63.6°C-values were determined for one strain per serogroup. Each strain was grown to stationary phase in brain heart infusion broth (BHIB; pH 7.0) and inoculated into prewarmed BHIB in a shaking water bath for thermotolerance experiments at 54.6, 58.0, or 63.6°C (three trials per strain). Samples were heated for up to 160 min at 54.6°C, 3 min at 58.0°C, or 45 s at 63.6°C, with periodic sampling followed by rapid cooling and plating on modified Levine's eosin methylene blue agar. For each strain and temperature, the log CFU per milliliter was plotted versus time, and D-values were determined. Across all strains, the least and most heat tolerant STEC serogroups at 58°C were O145 and O157, respectively. D58°C-values in BHIB ranged from 0.44 min for an O145 strain to 1.42 min for an O157:H7 strain. D58°C-values for O157 STEC strains were significantly higher than those for at least one strain in each of the non-O157 STEC serogroups (P < 0.05) except for serogroup O103. At 54.6°C, the most heat-resistant STEC strain belonged to serogroup O103 and was significantly more heat tolerant than the O157:H7 strains (P < 0.05). Grouping the strains, there were no significant differences in heat tolerance between O157 and non-O157 STEC at 63.6°C (P ≥ 0.05). The z-values for non-O157 STEC strains were comparable to those for O157:H7 STEC strains (P ≥ 0.05), ranging from 4.10 to 5.21°C. These results suggest that thermal processing interventions that target destruction of E. coli O157:H7 may have adequate lethality against non-O157 STEC.
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Affiliation(s)
- Akhila Vasan
- Department of Food Science, University of Wisconsin-Madison, 1605 Linden Drive, Madison, Wisconsin 53706, USA
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42
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Gabriel AA. Influences of simultaneous physicochemical stresses on injury and subsequent heat and acid resistances of Salmonella Enteritidis in apple juice. Food Control 2013. [DOI: 10.1016/j.foodcont.2012.08.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Koyuncu S, Andersson MG, Löfström C, Skandamis PN, Gounadaki A, Zentek J, Häggblom P. Organic acids for control of Salmonella in different feed materials. BMC Vet Res 2013; 9:81. [PMID: 23597100 PMCID: PMC3646707 DOI: 10.1186/1746-6148-9-81] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Accepted: 04/11/2013] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Salmonella control in animal feed is important in order to protect animal and public health. Organic acids is one of the control measures used for treatment of Salmonella contaminated feed or feed ingredients. In the present study, the efficacy of formic acid (FA) and different blends of FA, propionic acid (PA) and sodium formate (SF) was investigated. Four Salmonella strains isolated from feed were assayed for their acid tolerance. Also, the effect of lower temperatures (5°C and 15°C) compared to room temperature was investigated in rape seed and soybean meal. RESULTS The efficacy of acid treatments varied significantly between different feed materials. The strongest reduction was seen in pelleted and compound mash feed (2.5 log10 reduction) followed by rapeseed meal (1 log10 reduction) after 5 days exposure. However, in soybean meal the acid effects were limited (less than 0.5 log10 reduction) even after several weeks' exposure. In all experiments the survival curves showed a concave shape, with a fast initial death phase followed by reduction at a slower rate during the remaining time of the experiment.No difference in Salmonella reduction was observed between FA and a blend of FA and PA, whereas a commercial blend of FA and SF (Amasil) was slightly more efficacious (0.5-1 log10 reduction) than a blend of FA and PA (Luprocid) in compound mash feed. The Salmonella Infantis strain was found to be the most acid tolerant strain followed by, S. Putten, S. Senftenberg and S. Typhimurium. The tolerance of the S. Infantis strain compared with the S. Typhimurium strain was statistically significant (p<0.05). The lethal effect of FA on the S. Typhimurium strain and the S. Infantis strain was lower at 5°C and 15°C compared to room temperatures. CONCLUSIONS Acid treatment of Salmonella in feed is a matter of reducing the number of viable bacterial cells rather than eliminating the organism. Recommendations on the use of acids for controlling Salmonella in feed should take into account the relative efficacy of acid treatment in different feed materials, the variation in acid tolerance between different Salmonella strains, and the treatment temperature.
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Affiliation(s)
- Sevinc Koyuncu
- Department of Chemistry, Environment and Feed hygiene, National Veterinary Institute (SVA), Uppsala, Sweden
| | - Mats Gunnar Andersson
- Department of Chemistry, Environment and Feed hygiene, National Veterinary Institute (SVA), Uppsala, Sweden
| | - Charlotta Löfström
- National Food Institute, Technical University of Denmark (DTU), Søborg, Denmark
| | - Panagiotis N Skandamis
- Department of Food Science and Technology, Agricultural University of Athens (AUA), Athens, Greece
| | - Antonia Gounadaki
- Department of Food Science and Technology, Agricultural University of Athens (AUA), Athens, Greece
| | - Jürgen Zentek
- Institute of Animal nutrition, Freie Universität Berlin (FUB), Berlin, Germany
| | - Per Häggblom
- Department of Chemistry, Environment and Feed hygiene, National Veterinary Institute (SVA), Uppsala, Sweden
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Smith JL, Fratamico PM. Effect of stress on non-O157 Shiga toxin-producing Escherichia coli. J Food Prot 2012; 75:2241-50. [PMID: 23212025 DOI: 10.4315/0362-028x.jfp-12-255] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Non-O157 Shiga toxin-producing Escherichia coli (non-O157 STEC) strains have emerged as important foodborne pathogens worldwide. Non-O157 STEC serogroups O26, O45, O103, O111, O121, and O145 have been declared as adulterants in beef by the U. S. Department of Agriculture Food Safety and Inspection Service. While documentation is limited, treatments including heat and acid that have been shown to inactivate E. coli O157:H7 will likely also destroy non-O157 STEC; however, non-O157 STEC strains show variability in their responses to stress. It has been shown that non-O157 STEC may survive in fermented sausages and cheeses, and treatments such as high pressure may be necessary to eliminate non-O157 STEC from these products. The mechanisms used by non-O157 STEC to resist acid environments are similar to those used by O157:H7 strains and include the acid tolerance response, the oxidative system, and the glutamate and arginine decarboxylase systems. However, one study demonstrated that some non-O157 STEC strains utilize a chaperone-based acid stress response (HdeA and HdeB) to combat acidic conditions, which is lacking in E. coli O157:H7. Genomic studies suggest that while non-O157 STEC can cause diseases similar to those caused by E. coli O157:H7, O157 and non-O157 STECs have different evolutionary histories. Non-O157 STECs are a heterogeneous group of organisms, and there is currently a limited amount of information on their virulence, fitness, and stress responses, rendering it difficult to draw firm conclusions on their behavior when exposed to stress in the environment, in food, and during processing.
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Affiliation(s)
- James L Smith
- U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, Wyndmoor, PA 19038, USA.
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Gabriel AA. Influences of heating temperature, pH, and soluble solids on the decimal reduction times of acid-adapted and non-adapted Escherichia coli O157:H7 (HCIPH 96055) in a defined liquid heating medium. Int J Food Microbiol 2012; 160:50-7. [PMID: 23141645 DOI: 10.1016/j.ijfoodmicro.2012.09.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Revised: 09/01/2012] [Accepted: 09/11/2012] [Indexed: 10/27/2022]
Abstract
The study characterized the influences of various combinations of process and product parameters namely, heating temperature (53, 55, 57.5, 60, 62 °C), pH (2.0, 3.0, 4.5, 6.0, 7.0), and soluble solids (SS) (1.4, 15, 35, 55, 69°Brix) on the thermal inactivation of non-adapted and acid-adapted E. coli O157:H7 (HCIPH 96055) in a defined liquid heating medium (LHM). Acid adaptation was conducted by propagating cells in a gradually acidifying nutrient broth medium, supplemented with 1% glucose. The D values of non-adapted cells ranged from 1.43 s (0.02 min) to 304.89 s (5.08 min). Acid-adapted cells had D values that ranged from 1.33 s (0.02 min) to 2628.57 s (43.81 min). Adaptation did not always result in more resistant cells as indicated by the Log (D(adapted)/D(non-adapted)) values calculated in all combinations tested, with values ranging from -1.10 to 1.40. The linear effects of temperature and pH, and the joint effects of pH and SS significantly influenced the thermal resistance of non-adapted cells. Only the linear and quadratic effects of both pH and SS significantly influenced the D values of acid-adapted cells. Generally, the D values of acid-adapted cells decreased at SS greater than 55 °Brix, suggesting the possible cancelation of thermal cross protection by acid habituation at such SS levels. The relatively wide ranges of LHM pH and SS values tested in the study allowed for better examination of the effects of these factors on the thermal death of the pathogen. The results established in this work may be used in the evaluation, control and improvement of safety of juice products; and of other liquid foods with physicochemical properties that fall within the ranges tested in this work.
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Affiliation(s)
- Alonzo A Gabriel
- Department of Food Science and Nutrition, College of Home Economics, University of the Philippines, Diliman, Quezon City, Philippines.
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Vadlamudi S, Taylor TM, Blankenburg C, Castillo A. Effect of chemical sanitizers on Salmonella enterica serovar Poona on the surface of cantaloupe and pathogen contamination of internal tissues as a function of cutting procedure. J Food Prot 2012; 75:1766-73. [PMID: 23043824 DOI: 10.4315/0362-028x.jfp-12-159] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Survival of Salmonella enterica subsp. enterica serovar Poona on surface and stem scar portions of inoculated cantaloupe following sanitizer application, transfer of pathogen from the rind to the flesh during cutting, and growth of Salmonella Poona on cantaloupe cubes over 15 days of refrigerated storage were investigated. Cantaloupes inoculated with a rifampin-resistant strain of Salmonella Poona (10(7) CFU/ml) for 3 min and dried for 12 h were washed with chlorine (200 mg free chlorine per liter, 3 min), lactic acid (2%, 2 min), or ozone (30 mg/liter, 5 min). Fresh-cut cantaloupe cubes were prepared by (i) cutting the cantaloupe and then removing the rind or by (ii) peeling the rind and then cutting the flesh into pieces. The numbers of Salmonella bacteria recovered were higher in the stem scar portion (6.3 ± 0.3 log CFU/cm(2)) than the surface (4.8 ± 0.2 log CFU/cm(2)). Surface treatment with tap water or chlorine did not reduce Salmonella numbers, while treatment with lactic acid or ozone reduced Salmonella by 2.5 or 2.3 log CFU/cm(2), respectively. The use of lactic acid to sanitize the cantaloupes resulted in less Salmonella transfer to flesh during cutting; Salmonella numbers decreased to below detectable levels over 9 days of refrigerated (4°C) storage. Cutting cantaloupes after peeling the rind was more effective at reducing transfer of Salmonella to the internal tissue than cutting of cantaloupes prior to rind removal. These data suggest that treatment of cantaloupe rinds with lactic acid or ozone may be effective at reducing Salmonella numbers, while lactic acid application resulted in reduction of Salmonella transfer to cantaloupe flesh.
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Affiliation(s)
- Sasi Vadlamudi
- Department of Animal Science, Texas A&M University, College Station, Texas 77843-2471, USA
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Choi MR, Liu Q, Lee SY, Jin JH, Ryu S, Kang DH. Inactivation of Escherichia coli O157:H7, Salmonella typhimurium and Listeria monocytogenes in apple juice with gaseous ozone. Food Microbiol 2012; 32:191-5. [DOI: 10.1016/j.fm.2012.03.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Revised: 03/02/2012] [Accepted: 03/05/2012] [Indexed: 10/28/2022]
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YANG YISHAN, TEO JIAHAN, BANG WOOSUK, YUK HYUNGYUN. CHANGES IN ACID AND HEAT RESISTANCE OF SALMONELLA NEWPORT AND SALMONELLA SAINTPAUL STORED IN MANGO AND PINEAPPLE JUICES. J Food Saf 2012. [DOI: 10.1111/j.1745-4565.2012.00382.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Studies on the pathogenesis and survival of different culture forms of Listeria monocytogenes to pulsed UV-light irradiation after exposure to mild-food processing stresses. Food Microbiol 2012; 30:330-9. [DOI: 10.1016/j.fm.2011.12.024] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Revised: 12/27/2011] [Accepted: 12/28/2011] [Indexed: 12/22/2022]
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50
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Gabriel AA. Microbial inactivation in cloudy apple juice by multi-frequency Dynashock power ultrasound. ULTRASONICS SONOCHEMISTRY 2012; 19:346-351. [PMID: 21802974 DOI: 10.1016/j.ultsonch.2011.06.003] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Revised: 05/29/2011] [Accepted: 06/06/2011] [Indexed: 05/31/2023]
Abstract
The study determined the efficacy of Dynashock wave power ultrasound as an alternative processing technique for apple juice against a number of pathogenic and spoilage microorganisms. The effects of several implicit, intrinsic and extrinsic properties on the Dynashock wave inactivation of the microorganisms were also investigated. Results showed that acid adaptation increased the resistance of Escherichia coli O157:H7 and Salmonella spp. but decreased that of Listeria monocytogenes. Spoilage yeast mixed inoculum composed of Debaryomyces hansenii, Torulaspora delbrueckii, Clavispora lusitaniae, Pichia fermentans and Saccharomyces cerevisiae was found to be more resistant than any of the adapted or non-adapted pathogens. Among the individual, acid-adapted E. coli O157:H7, the MN-28 isolate was found most resistant; while three other individual isolates had greater resistance than the composited E. coli inoculum. Increased in pulp content decreased the efficacy of Dynashock waves, but co-treatment with ultraviolet-C rays significantly enhanced inactivation in the cloudy apple juice. The results demonstrated the potential of Dynashock wave technology, together with other antimicrobial hurdles as alternative juice processing technique/s.
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Affiliation(s)
- Alonzo A Gabriel
- Laboratory of Food Microbiology and Hygiene, Department of Biofunctional Science and Technology, Graduate School of Biosphere Science, Hiroshima University, 1-4-4 Kagamiyama, Higashi Hiroshima City, Hiroshima 739-8528, Japan.
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