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Doddabematti Prakash S, Rivera J, Sabillón L, Siliveru K. From wheat grain to flour: a review of potential sources of enteric pathogen contamination in wheat milled products. Crit Rev Food Sci Nutr 2024:1-11. [PMID: 38766719 DOI: 10.1080/10408398.2024.2353892] [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: 05/22/2024]
Abstract
The number of food safety issues linked to wheat milled products have increased in the past decade. These incidents were mainly caused by the contamination of wheat-based products by enteric pathogens. This manuscript is the first of a two-part review on the status of the food safety of wheat-based products. This manuscript focused on reviewing the available information on the potential pre-harvest and post-harvest sources of microbial contamination, and potential foodborne pathogens present in wheat-based products. Potential pre-harvest sources of microbial contamination in wheat included animal activity, water, soil, and manure. Improper grain storage practices, pest activity, and improperly cleaned and sanitized equipment are potential sources of post-harvest microbial contamination for wheat-based foods. Raw wheat flour products and flour-based products are potentially contaminated with enteric pathogens such as Shiga toxin-producing E. coli (STECs), and Salmonella at low concentrations. Wheat grains and their derived products (i.e., flours) are potential vehicles for foodborne illness in humans due to the presence of enteric pathogens. A more holistic approach is needed for assuring the food safety of wheat-based products in the farm-to-table continuum. Future developments in the wheat supply chain should also be aimed at addressing this emerging food safety threat.
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Affiliation(s)
| | - Jared Rivera
- Department of Grain Science and Industry, Kansas State University, Manhattan, KS, USA
| | - Luis Sabillón
- Department of Family Consumer Sciences, New Mexico State University, Las Cruces, NM, USA
- Center of Excellence in Sustainable Food and Agricultural Systems, New Mexico State University, Las Cruces, NM, USA
| | - Kaliramesh Siliveru
- Department of Grain Science and Industry, Kansas State University, Manhattan, KS, USA
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Shivaprasad DP, Rivera J, Siliveru K. Acidic water tempering and heat treatment, a hurdle approach to reduce wheat Salmonella load during tempering and its effects on flour quality. Food Res Int 2024; 176:113723. [PMID: 38163681 DOI: 10.1016/j.foodres.2023.113723] [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: 09/10/2023] [Revised: 11/05/2023] [Accepted: 11/22/2023] [Indexed: 01/03/2024]
Abstract
The cultivation and processing of wheat render it susceptible to microbial contamination from varied sources. Hence, pathogens such as Salmonella can contaminate wheat grains, which poses a food safety risk in wheat-based products. This risk is displayed by the incidence of foodborne illness outbreaks linked to Salmonella-contaminated wheat flour and flour-based products. The purpose of this study was to assess the effectiveness of combining acidic water and heat treatment in reducing the Salmonella load of hard red spring (HRS) wheat grains during tempering. Effective treatments were then evaluated for their effects on wheat flour quality. Tempering with sodium bisulfate (SBS), lactic acid (LA), and citric acid (CA) at 15% w/v alone reduced (p < 0.001) wheat Salmonella load by 3.15, 3.23, and 2.91 log CFU/g, respectively. Heat treatment (55 °C) reduced (p < 0.001) wheat Salmonellaload by 4.1 log CFU/g after 24 h of tempering. Combining both tempering and heat treatments resulted in a greater reduction in Salmonella load as non-detectable levels (<2 log CFU/g) of Salmonella in the wheat grains were obtained after 12 h of tempering with LA (15%) + heat. A similar result were achieved for both SBS (15%) + heat and CA (15%) + heat treatments after 18 h of tempering. Applying the combined treatments in HRS wheat grains resulted in comparable wheat flour baking (volume, texture, and crumb structure) and physicochemical properties (rheology and composition) relative to the control (tempering with water alone). The results from this study has the potential to be utilized for developing more effective methods for improving the food safety of wheat flour against Salmonella contamination.
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Affiliation(s)
| | - Jared Rivera
- Department of Grain Science and Industry, Kansas State University, Manhattan, KS 66506, USA
| | - Kaliramesh Siliveru
- Department of Grain Science and Industry, Kansas State University, Manhattan, KS 66506, USA.
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Lin Y, Suehr Q, Dolan K, Simsek S, Bergholz TM. Inactivation of Salmonella and Shiga-toxin producing Escherichia coli on soft wheat kernels using vacuum steam pasteurization. Int J Food Microbiol 2023; 406:110375. [PMID: 37660435 DOI: 10.1016/j.ijfoodmicro.2023.110375] [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: 03/24/2023] [Revised: 08/21/2023] [Accepted: 08/29/2023] [Indexed: 09/05/2023]
Abstract
Wheat, the raw material for flour milling, can be contaminated with enteric pathogens, leading to outbreaks linked to flour. In previous lab-scale studies, vacuum steam treatment was able to reduce Salmonella Enteritidis PT30 and Shiga-toxin producing E. coli (STEC) O121 levels on soft wheat kernels while maintaining flour quality and gluten functionality. This study used a newly designed lab-scale vacuum steam pasteurizer (VSP) to evaluate its efficacy to inactivate multiple strains of Salmonella and STEC on soft wheat by modeling the non-isothermal time-temperature history during treatment and reduction of the microbial populations. The results demonstrated that vacuum steam treatment could effectively disinfect wheat grains inoculated with enteric pathogens. In this study, Salmonella strains were less thermally resistant than STEC strains. The D75°C of Salmonella strains were 2.8 and 3.2 min, and the D75°C of STEC ranged from 3.1 to 4.6 min. E. faecium had a D75°C of 3.3 min, which indicates that it could be used as surrogate for larger scale evaluation of vacuum steam pasteurization in the future but was not conservative compared to some of the STEC strains.
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Affiliation(s)
- Yawei Lin
- Department of Food Science and Human Nutrition, Michigan State University, East Lansing, MI 48824, United States of America
| | - Quincy Suehr
- Department of Biosystems and Agricultural Engineering, Michigan State University, East Lansing, MI 48824, United States of America
| | - Kirk Dolan
- Department of Food Science and Human Nutrition, Michigan State University, East Lansing, MI 48824, United States of America; Department of Biosystems and Agricultural Engineering, Michigan State University, East Lansing, MI 48824, United States of America
| | - Senay Simsek
- Whistler Center for Carbohydrate Research, Department of Food Science, Purdue University, West Lafayette, IN 47907, United States of America
| | - Teresa M Bergholz
- Department of Food Science and Human Nutrition, Michigan State University, East Lansing, MI 48824, United States of America.
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Rivera J, D P S, Vikram A, Siliveru K. Phage Biocontrol Effectively Reduces Contamination of Wheat with Shiga Toxin-producing Escherichia coli O121 and O26 Without Adverse Effects on Flour Quality. J Food Prot 2023; 86:100137. [PMID: 37532225 DOI: 10.1016/j.jfp.2023.100137] [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: 04/16/2023] [Revised: 07/25/2023] [Accepted: 07/26/2023] [Indexed: 08/04/2023]
Abstract
Contamination of wheat flours with Shiga toxin-producing E. coli (STEC) is a concern for the milling industry. Milling-specific interventions are needed to address this food safety hazard. The objectives for this study were to determine the efficacy of bacteriophage treatment in reducing wheat STEC contamination during tempering, and assess its effects on flour milling and baking quality. Bacteriophage solutions were prepared by mixing sterile water with the bacteriophage treatment at the following levels: 1 × 106 (0.1%), 2.5 × 106 (0.25%), 5 × 106 (0.5%), 1 × 107 (1.0%), and 1 × 108 (10%) PFU/g wheat dosage. Sterile water (0%) was used as the control. Predried wheat grains were inoculated with STEC (O121 and O26) at 5.0 and 6.0 log CFU/g to restore its original moisture content followed by resting for 24 h. Inoculated grains were then tempered (16% moisture, 24 h) using the prepared bacteriophage solutions. Grains were sampled at 0.5, 1, 2, 6, 12, 18, and 24 h during tempering to determine STEC concentration. The effects of the phage solutions on the flour milling and baking quality were also tested. Tempering time, bacteriophage dose, and their interaction had significant effects on phage efficacy (P < 0.05), with better reductions observed at longer tempering times and higher bacteriophage doses. The use of phage solutions reduced (P < 0.05) wheat STEC concentration after tempering, with the 10% treatment (3.2 logs) achieving ahigher reduction than the 1% (2.4 logs) treatment under similar phage preparation. Phage tempering (including at the highest concentration examined, i.e., 10%) produced wheat flours with comparable quality to the control. Phage-treated wheat flour resulted in breads with finer crumb structure, and comparable texture compared to the control. Phage tempering is a viable intervention for wheat milling as it reduced STEC loads of wheat with no detrimental effects to flour milling and baking quality.
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Affiliation(s)
- Jared Rivera
- Department of Grain Science and Industry, Kansas State University, Manhattan, KS 66506, USA
| | - Shivaprasad D P
- Department of Grain Science and Industry, Kansas State University, Manhattan, KS 66506, USA
| | - Amit Vikram
- Intralytix, Inc., 8681 Robert Fulton Dr, Columbia, MD 21046, USA
| | - Kaliramesh Siliveru
- Department of Grain Science and Industry, Kansas State University, Manhattan, KS 66506, USA.
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5
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Adaro M, Ibáñez ÁGS, Origone AL, Vallés D, Guzmán F, Vega A, Barberis S. Enzymatic synthesis of new antimicrobial peptides for food purposes. Front Microbiol 2023; 14:1153135. [PMID: 37260684 PMCID: PMC10227576 DOI: 10.3389/fmicb.2023.1153135] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Accepted: 04/28/2023] [Indexed: 06/02/2023] Open
Abstract
Growing consumer awareness of the potential negative health effects of synthetic antibiotics has prompted the search for more natural preservatives that can improve the safety and quality of food. In this study we report the enzymatic synthesis of N-α-[Carbobenzyloxy]-Ile-Gln (Z-IQ) which is the precursor of Ile-Gln (IQ), a new antibacterial dipeptide, using an aqueous-organic biphasic system formed by 50% (v/v) ethyl acetate in 0.1 M Tris - HCl buffer pH 8. A partially purified proteolytic extract from the fruits of Solanum granuloso leprosum, named granulosain, proved to be a robust biocatalyst for the synthesis of Z-IQ, eliciting 71 ± 0.10% maximal peptide yield in the above described conditions. After cleaving and purifying IQ dipeptide, antimicrobial activity was assayed against Staphylococcus aureus ATCC 25923, Staphylococcus hominis A17771, and Staphylococcus aureus C00195, and MIC values between 118 ± 0.01 μg/mL and 133.7 ± 0.05 μg/mL were obtained. In addition, IQ showed MIC of 82.4 ± 0.01 μg/mL and 85.0 ± 0.00 μg/mL against Escherichia coli ATCC 25922 and Escherichia coli A17683, respectively. IQ did not show inhibitory activity against single-drug resistance (SDR) strains, such as Klebsiella oxytoca A19438 (SDR) and Pseudomonas aeruginosa C00213 (SDR), and against multidrug-resistant Enterococcus faecalis I00125 (MDR). IQ also caused growth inhibition of Helicobacter pylori NCTC 11638 and three wild-type H. pylori strains, which are sensitive to AML, MTZ, LEV and CLA (H. pylori 659), resistant to LEV (H. pylori 661 SDR), and resistant to MTZ (H. pylori 662 SDR). Finally, this study contributes with a new dipeptide (IQ) that can be used as an antimicrobial agent for food preservation or as a safe ingredient of functional foods.
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Affiliation(s)
- Mauricio Adaro
- Laboratorio de Bromatología, Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, San Luis, Argentina
- Instituto de Física Aplicada (INFAP) – CCT - San Luis - CONICET, Piso, San Luis, Argentina
| | - Ángel Gabriel Salinas Ibáñez
- Instituto de Física Aplicada (INFAP) – CCT - San Luis - CONICET, Piso, San Luis, Argentina
- Laboratorio de Microbiología e Inmunología, Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, San Luis, Argentina
| | - Anabella Lucia Origone
- Laboratorio de Bromatología, Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, San Luis, Argentina
- Instituto de Física Aplicada (INFAP) – CCT - San Luis - CONICET, Piso, San Luis, Argentina
| | - Diego Vallés
- Laboratorio de Biocatalizadores y sus Aplicaciones, Instituto de Química Biológica, Facultad de Ciencias, Universidad de la República (UdelaR), Montevideo, Uruguay
| | - Fanny Guzmán
- Laboratorio de Péptidos, Núcleo de Biotecnología Curauma, Pontificia Universidad Católica de Valparaíso, Curauma, Valparaíso, Chile
| | - Alba Vega
- Laboratorio de Microbiología e Inmunología, Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, San Luis, Argentina
| | - Sonia Barberis
- Laboratorio de Bromatología, Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, San Luis, Argentina
- Instituto de Física Aplicada (INFAP) – CCT - San Luis - CONICET, Piso, San Luis, Argentina
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Lin Y, Simsek S, Bergholz TM. Fate of salmonella and shiga-toxin producing Escherichia coli on wheat grain during tempering. Food Microbiol 2023; 111:104194. [PMID: 36681398 DOI: 10.1016/j.fm.2022.104194] [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: 10/05/2022] [Revised: 11/23/2022] [Accepted: 11/24/2022] [Indexed: 11/27/2022]
Abstract
Outbreaks of Salmonella and Shiga-toxin producing Escherichia coli (STEC) linked to wheat flour led to increased interest in characterizing the fate of Salmonella and STEC on wheat during processing. Tempering is the stage of wheat processing where water is added to toughen the bran prior to milling, which has the potential to influence pathogen behavior on the kernels. This study aimed to quantify changes in the numbers of STEC and Salmonella inoculated onto soft red winter wheat, and to observe potential changes in the distribution of the pathogens on the surface of kernels during tempering. Lab-scale tempering experiments were conducted to quantify the water activity of and bacterial populations on wheat grain at various time points during 16 h of tempering. The highest water activity observed throughout 16 h of tempering was 0.88. There was no significant change (p > 0.05) in numbers of Salmonella, STEC, or native mesophiles. Using confocal microscopy, observation of Salmonella and STEC cells expressing mCherry on wheat kernels showed an even distribution of inoculated cells, though the localization of cells on kernels did not change significantly after tempering. Even though the environment was not favorable for pathogen replication on grain, the population remained stable, suggesting that disinfection of the kernels prior to milling could reduce food safety concerns in flour.
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Affiliation(s)
- Yawei Lin
- Department of Food Science and Human Nutrition, Michigan State University, East Lansing, MI, 48824, USA
| | - Senay Simsek
- Whistler Center for Carbohydrate Research, Department of Food Science, Purdue University, West Lafayette, IN, 47907, USA
| | - Teresa M Bergholz
- Department of Food Science and Human Nutrition, Michigan State University, East Lansing, MI, 48824, USA.
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Oguadinma I, Mishra A, Dev Kumar G. Antibiotic resistance associated lactic acid cross tolerance in Shiga-toxin producing E. coli. Front Microbiol 2023; 14:1059144. [PMID: 37180239 PMCID: PMC10169816 DOI: 10.3389/fmicb.2023.1059144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 03/21/2023] [Indexed: 05/16/2023] Open
Abstract
Introduction The occurrence of antibiotic resistant (ABR) bacteria in foods is a growing public health challenge. We evaluated sanitizer cross-tolerance among ABR Escherichia coli (E. coli) O157:H7 and non-O157:H7 Shiga-toxin producing E. coli (STEC) serogroups. Sanitizer tolerance in STEC could be a public health concern as mitigation strategies against the pathogen might be compromised. Methods Resistance to ampicillin and streptomycin were evolved in E. coli serogroups: O157:H7 (H1730, and ATCC 43895), O121:H19 and O26:H11. Resistance to antibiotics was evolved chromosomally through incremental exposure to ampicillin (amp C) and streptomycin (strep C). Transformation using a plasmid was performed to confer resistance to ampicillin to generate amp P strep C. Results The minimum inhibitory concentration (MIC) of lactic acid for all strains evaluated was 0.375% v/v. Analysis of bacterial growth parameters in tryptic soy broth amended with 0.0625% v/v, 0.125% v/v, and 0.25% v/v (subMIC) lactic acid indicated that growth correlated positively with the lag phase duration, and negatively with both the maximum growth rate and change in population density for all strains evaluated except for the highly tolerant variant- O157:H7 amp P strep C. Strains O121 NR (non-ABR), O121 amp C, O121 amp P strep C, O157:H7 H1730 amp C and O157:H7 H1730 amp P strep C were not inactivated after exposure to 1% and 2.5% v/v lactic acid for 300 s. No recovery of cells was observed after the strains were exposed to 5% v/v lactic acid for 300 s. ABR strains O157:H7 H1730 amp C and O157: H7 H1730 amp P strep C demonstrated a high tolerance to lactic acid (P ≤ 0.05). Conclusion ABR in isolate E. coli O157: H7 H1730 may improve tolerance to lactic acid. Increased tolerance may be discerned by evaluating growth parameters of bacteria in presence of sub-MIC levels of lactic acid.
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Affiliation(s)
- Ikechukwu Oguadinma
- Center for Food Safety, The University of Georgia, Griffin, GA, United States
| | - Abhinav Mishra
- Department of Food Science & Technology, The University of Georgia, Athens, GA, United States
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8
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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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9
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Lin Y, Simsek S, Bergholz TM. Impact of Chlorinated Water on Pathogen Inactivation during Wheat Tempering and Resulting Flour Quality. J Food Prot 2022; 85:1210-1220. [PMID: 35653628 DOI: 10.4315/jfp-22-076] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 05/21/2022] [Indexed: 11/11/2022]
Abstract
ABSTRACT Outbreaks of enteric pathogens linked to wheat flour have led the wheat milling industry to seek solutions addressing this food safety concern. Chlorinated water at 400 to 700 ppm has been used in the flour milling industry as a tempering aid to control growth of yeast and mold in tempering bins. However, the effectiveness of chlorinated water for inactivating enteric pathogens on wheat kernels was unknown. Five strains of Shiga toxin-producing Escherichia coli and two strains of Salmonella were inoculated onto hard red spring wheat at 7 log CFU/g and stored at room temperature for 1 month. Inoculated wheat was tempered with four concentrations (0, 400, 800, and 1,200 ppm) of chlorinated water (pH 6.5). The reduction due to chlorine was determined by calculating change in microbial loads at each chlorine level by using the response at 0 ppm as a reference. Uninoculated wheat tempered with chlorinated water was used to measure flour quality parameters. Changes in pathogen population over 18 h ranged from -2.35 to -0.30 log CFU/g with 800 ppm of chlorinated water and were not significantly different from changes at 400 and 1,200 ppm. Significant (P < 0.05) differences in the extent of reduction were observed among strains. However, the effect of chlorinated water at reducing native microbes on wheat kernels was minimal, with an average reduction of 0.39 log CFU/g for all concentrations. No significant (P > 0.05) changes occurred in flour quality and gluten functionality or during bread making for grains tempered at 400 and 800 ppm of chlorinated water. There were small but significant (P < 0.05) changes in flour protein content, final viscosity, and water absorption when tempered with 1,200 ppm of chlorinated water. The data showed that the level of chlorinated water currently used in industry for tempering could reduce enteric pathogen numbers by 1.22 log CFU/g for Shiga toxin-producing Escherichia coli and 2.29 log CFU/g for Salmonella, with no significant effects on flour quality and gluten functionality. HIGHLIGHTS
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Affiliation(s)
- Yawei Lin
- Department of Food Science and Human Nutrition, Michigan State University, East Lansing, Michigan 48824
| | - Senay Simsek
- Whistler Center for Carbohydrate Research, Department of Food Science, Purdue University, West Lafayette, Indiana 47907, USA
| | - Teresa M Bergholz
- Department of Food Science and Human Nutrition, Michigan State University, East Lansing, Michigan 48824
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10
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Effects of tempering with plasma-activated water on total plate count and quality properties of wheat flour. J Cereal Sci 2022. [DOI: 10.1016/j.jcs.2022.103468] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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11
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Lauer JR, Simsek S, Bergholz TM. Fate of Salmonella and Enterohemorrhagic Escherichia coli on Wheat Grain. J Food Prot 2021; 84:2109-2115. [PMID: 34347868 DOI: 10.4315/jfp-21-076] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 08/01/2021] [Indexed: 11/11/2022]
Abstract
ABSTRACT Wheat flour has been connected to outbreaks of foodborne illnesses with increased frequency in recent years, specifically, outbreaks involving Salmonella enterica and enterohemorrhagic Escherichia coli (EHEC). However, there is little information regarding the survival of these pathogens on wheat grain during long-term storage in a low-moisture environment. This study aims to evaluate the long-term survival of these enteric pathogens on wheat grain over the course of a year. Hard red spring wheat was inoculated with strains of four serovars of Salmonella (Enteritidis, Agona, Tennessee, and Montevideo) and six serotypes of EHEC (O157:H7, O26:H11, O121:H19, O45:NM, O111:H8, and O103:H2) in triplicate, sealed in Mylar bags to maintain the water activity, and stored at room temperature (22 ± 1°C). The survival of each pathogen was evaluated by plating onto differential media. Viable counts of strains from all four serovars of Salmonella (Enteritidis, Agona, Tennessee, and Montevideo) were detected on wheat grain stored at room temperature (22 ± 1°C) for the duration of the study (52 weeks). Viable counts of strains from EHEC serotypes O45:NM, O111:H8, and O26:H11 were only detected for 44 weeks, and strains from serotypes O157:H7, O121:H19, and O103:H2 were only detected for 40 weeks until they passed below the limit of detection (2.0 log CFU/g). The D-values were found to be significantly different between Salmonella and EHEC (adjusted P ≤ 0.05) with Salmonella D-values ranging from 22.9 ± 2.2 weeks to 25.2 ± 1.0 weeks and EHEC D-values ranging from 11.4 ± 0.6 weeks to 13.1 ± 1.8 weeks. There were no significant differences among the four Salmonella strains or among the six EHEC strains (adjusted P > 0.05). These observations highlight the wide range of survival capabilities of enteric pathogens in a low-moisture environment and confirm these pathogens are a food safety concern when considering the long shelf life of wheat grain and its products. HIGHLIGHTS
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Affiliation(s)
- Jessica R Lauer
- Department of Microbiological Sciences, North Dakota State University, Fargo, North Dakota 58108
| | - Senay Simsek
- Department of Plant Sciences, North Dakota State University, Fargo, North Dakota 58108
| | - Teresa M Bergholz
- Department of Food Science and Human Nutrition, Michigan State University, East Lansing, Michigan 48824, USA
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12
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Rivera J, Phebus RK, Doddabematti Prakash S, Siliveru K. Effects of acidic water tempering and heat treatment on the Shiga toxin‐producing
Escherichia coli
(O121 and O26) load of wheat during tempering and its impact on wheat flour quality. J FOOD PROCESS PRES 2021. [DOI: 10.1111/jfpp.16155] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Jared Rivera
- Department of Grain Science and Industry Kansas State University Manhattan Kansas USA
| | | | | | - Kaliramesh Siliveru
- Department of Grain Science and Industry Kansas State University Manhattan Kansas USA
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13
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Lin B, Zhu Y, Zhang L, Xu R, Guan X, Kou X, Wang S. Effect of Physical Structures of Food Matrices on Heat Resistance of Enterococcus faecium NRRL-2356 in Wheat Kernels, Flour and Dough. Foods 2020; 9:foods9121890. [PMID: 33352900 PMCID: PMC7765854 DOI: 10.3390/foods9121890] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Revised: 12/10/2020] [Accepted: 12/16/2020] [Indexed: 02/07/2023] Open
Abstract
Nonpathogenic surrogate microorganisms, with a similar or slightly higher thermal resistance of the target pathogens, are usually recommended for validating practical pasteurization processes. The aim of this study was to explore a surrogate microorganism in wheat products by comparing the thermal resistance of three common bacteria in wheat kernels and flour. The most heat-resistant Enterococcus faecium NRRL-2356 rather than Salmonella cocktail and Escherichia coli ATCC 25922 was determined when heating at different temperature-time combinations at a fixed heating rate of 5 °C/min in a heating block system. The most heat-resistant pathogen was selected to investigate the influences of physical structures of food matrices. The results indicated that the heat resistance of E. faecium was influenced by physical structures of food matrices and reduced at wheat kernel structural conditions. The inactivation of E. faecium was better fitted in the Weibull distribution model for wheat dough structural conditions while in first-order kinetics for wheat kernel and flour structural conditions due to the changes of physical structures during heating. A better pasteurization effect could be achieved in wheat kernel structure in this study, which may provide technical support for thermal inactivation of pathogens in wheat-based food processing.
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Affiliation(s)
- Biying Lin
- College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling 712100, China; (B.L.); (L.Z.); (R.X.); (X.G.); (X.K.)
| | - Yufei Zhu
- College of Animal Science and Technology, Northwest A&F University, Yangling 712100, China;
| | - Lihui Zhang
- College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling 712100, China; (B.L.); (L.Z.); (R.X.); (X.G.); (X.K.)
| | - Ruzhen Xu
- College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling 712100, China; (B.L.); (L.Z.); (R.X.); (X.G.); (X.K.)
| | - Xiangyu Guan
- College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling 712100, China; (B.L.); (L.Z.); (R.X.); (X.G.); (X.K.)
| | - Xiaoxi Kou
- College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling 712100, China; (B.L.); (L.Z.); (R.X.); (X.G.); (X.K.)
| | - Shaojin Wang
- College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling 712100, China; (B.L.); (L.Z.); (R.X.); (X.G.); (X.K.)
- Department of Biological Systems Engineering, Washington State University, Pullman, WA 99164-6120, USA
- Correspondence: ; Tel.: +86-29-87092391; Fax: +86-29-87091737
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14
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Simsek S, Snelling J, Malekmohammadi S, Bergholz TM. Vacuum steam treatment of soft wheat: Quality and reduction of
Escherichia coli
O121 and
Salmonella
Enteritidis PT30. Cereal Chem 2020. [DOI: 10.1002/cche.10356] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Senay Simsek
- Plant Sciences Department North Dakota State University Fargo ND USA
| | - Jane Snelling
- Plant Sciences Department North Dakota State University Fargo ND USA
| | | | - Teresa M. Bergholz
- Microbiological Sciences Department North Dakota State University Fargo ND USA
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Affiliation(s)
| | - Senay Simsek
- Department of Plant Sciences North Dakota State University Fargo ND USA
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