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Janahar JJ, Xu J, Balasubramaniam V, Yousef A, Ting E. Inactivation of Lactobacillus brevis cells and Bacillus cereus spores as influenced by pressure, shear, thermal, and valve geometry. INTERNATIONAL JOURNAL OF FOOD PROPERTIES 2023. [DOI: 10.1080/10942912.2023.2173227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Affiliation(s)
- Jerish Joyner Janahar
- Department of Food Science and Technology, The Ohio State University, Columbus, OH, USA
| | - Jie Xu
- Department of Food Science and Technology, The Ohio State University, Columbus, OH, USA
| | - V.M. Balasubramaniam
- Department of Food Science and Technology, The Ohio State University, Columbus, OH, USA
- Department of Food Agricultural and Biological Engineering, The Ohio State University, Columbus, OH, USA
| | - Ahmed Yousef
- Department of Food Science and Technology, The Ohio State University, Columbus, OH, USA
| | - Edmund Ting
- Pressure BioSciences Inc, South Easton, MA, USA
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Sun S, Xie Y, Zhou X, Zhu MJ, Sablani S, Tang J. Survival and thermal resistance of Salmonella in chocolate products with different water activities. Food Res Int 2023; 172:113209. [PMID: 37689954 DOI: 10.1016/j.foodres.2023.113209] [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: 02/24/2023] [Revised: 06/27/2023] [Accepted: 06/29/2023] [Indexed: 09/11/2023]
Abstract
Contamination of Salmonella in chocolate products has caused worldwide outbreaks and recalls. There is a lack of information on the impact of water activity (aw) on the stability of Salmonella in chocolate products during storage and thermal treatments. In this research, the survival and thermal resistance of a Salmonella cocktail (S. Enteritidis PT30, S. Tennessee K4643, S. Typhimurium S544) was examined in different chocolate products (dark chocolate, white chocolate, milk chocolate) at two aw levels (0.25, 0.50) over 12 months at 22 °C. A reduction of 4.19 log10 CFU/gof Salmonella was obtained in dark chocolate after 12 months (aw = 0.50, at 22 °C); less reductions were observed in white and milk chocolates. In all three products, more reductions were observed ataw = 0.50 than at aw = 0.25 over the 12-months storage. When treated at 80 °C, the D-values (time required to cause 1 log reduction) of the Salmonella cocktail in the chocolate samples with initial aw of 0.25 were 35.7, 25.2 and 11.6 min in dark, white and milk chocolate, respectively, before the storage. The D80°C -values of Salmonella cocktail in the samples with initial aw of 0.50 were 6.45, 7.46, and 3.98 min in dark, white and milk chocolate, respectively. After 12 months of storage at 22 °C, the D80°C-value of Salmonella cocktail decreased to 9.43 min (p < 0.05) in milk chocolate but remained 22.7 min in white chocolate with an aw of 0.25 at 22 °C. The data suggests that Salmonella can survive in chocolate products for up to 12 months, and its thermal resistance remained relatively stable. Thus, Salmonella is resistant to desiccation in chocolates, particularly in milk and white chocolates, and its thermal resistance remains during one-year storage, which could pose a potential threat for future outbreaks.
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Affiliation(s)
- Sicheng Sun
- Department of Biological Systems Engineering, Washington State University, Pullman, WA 99164, USA
| | - Yucen Xie
- Department of Biological Systems Engineering, Washington State University, Pullman, WA 99164, USA
| | - Xu Zhou
- Department of Biological Systems Engineering, Washington State University, Pullman, WA 99164, USA
| | - Mei-Jun Zhu
- School of Food Science, Washington State University, Pullman, WA 99164, USA
| | - Shyam Sablani
- Department of Biological Systems Engineering, Washington State University, Pullman, WA 99164, USA
| | - Juming Tang
- Department of Biological Systems Engineering, Washington State University, Pullman, WA 99164, USA.
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Qiu Y, Ozturk S, Cui X, Qin W, Wu Q, Liu S. Increased heat tolerance and transcriptome analysis of Salmonella enterica Enteritidis PT 30 heat-shocked at 42 ℃. Food Res Int 2023; 167:112636. [PMID: 37087231 DOI: 10.1016/j.foodres.2023.112636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 02/15/2023] [Accepted: 02/21/2023] [Indexed: 02/26/2023]
Abstract
In this study, we compared the heat tolerance parameter (D65℃) values of Salmonella enterica serovar Enteritidis PT 30 (S. Enteritidis ) heat adapted at different degrees (at 42 ℃ for 20-180 min) and cultivated using two methods. The treated group with the highest D65℃ value (LP-42 ℃-60 min) and the untreated groups (Control-TSB and Control-TSA) were subjected to transcriptome analysis. Heat-adaptation increased the D65℃ values of S. Enteritidis by 24.5-60.8%. The D65℃ values of the LP-42 ℃-60 min group (1.85 ± 0.13 min, 7.7% higher) was comparable to that of the Control-TSA. A total of 483 up- and 443 downregulated genes of S. enteritidis were identified in the LP-42 ℃-60 min group (log2fold change > 1, adjusted p-value < 0.05). Among these genes, 5 co-expressed and 15 differentially expressed genes in the LP-42 ℃-60 min and Control-TSA grops possibly contributed to the high D65℃ values of S. Enteritidis . The Rpo regulon was involved in the heat adaptation of S. Enteritidis , as evidenced by the significant upregulation of rpoS, rpoN, and rpoE. KEGG enrichment pathways, such as biosynthesis of secondary metabolites, tricarboxylic acid, and ribosomes were identified and mapped to reveal the molecular mechanisms of S. enteritidis during heat adaptation. This study quantified the enhanced heat tolerance of S. Enteritidis heat adapted at different degrees of heat-adaptation. The results of this study may serve as a basis for elucidating the molecular mechanisms underlying the enhanced heat tolerance at the transcriptome level.
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Affiliation(s)
- Yan Qiu
- College of Food Science, Sichuan Agricultural University, Ya'an, China
| | - Samet Ozturk
- Department of Food Engineering, Gümüşhane University, Gümüşhane, Turkey
| | - Xinyao Cui
- College of Food Science, Sichuan Agricultural University, Ya'an, China
| | - Wen Qin
- College of Food Science, Sichuan Agricultural University, Ya'an, China; Food Processing and Safety Institute, Sichuan Agricultural University, Ya'an, China
| | - Qingping Wu
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou 510070, China
| | - Shuxiang Liu
- College of Food Science, Sichuan Agricultural University, Ya'an, China; Food Processing and Safety Institute, Sichuan Agricultural University, Ya'an, China; State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou 510070, China.
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4
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Xue R, Wang H, Zhao D, Qin W, Lin H, Ye Q, Liu S. Identification of heat-resistant Bacillus strains in peppers in Sichuan Province, China. Lebensm Wiss Technol 2023. [DOI: 10.1016/j.lwt.2023.114425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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5
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Sun S, Xie Y, Yang R, Zhu MJ, Sablani S, Tang J. The influence of temperature and water activity on thermal resistance of Salmonella in milk chocolate. Food Control 2023. [DOI: 10.1016/j.foodcont.2022.109292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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6
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Ahmad NH, Marks BP, Ryser ET. Effect of Lactose and Milk Protein on Thermal Resistance of Enterococcus faecium NRRL B-2354 and Salmonella in Dairy Powders. J Food Prot 2022; 85:1865-1874. [PMID: 36173901 DOI: 10.4315/jfp-22-111] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 09/26/2022] [Indexed: 11/11/2022]
Abstract
ABSTRACT Microbial challenge studies using nonpathogenic surrogates provide a practical means for validating thermally based pathogen controls for low-moisture foods. Because the relative thermal resistance, or kill ratio, of Enterococcus faecium NRRL B-2354 (a nonpathogenic surrogate) to Salmonella is greatly influenced by food composition, this study assessed relative thermal resistance of a five-strain Salmonella cocktail and E. faecium in skim milk powder (SMP), lactose-free skim milk powder (LSMP), 90% milk protein isolate (MPI), and lactose powder (LP). The impact of sugar composition (lactose versus glucose-galactose) on resuscitation of bacterial survivors, by using SMP and LSMP, was also determined. Dairy powders were inoculated with agar-grown cultures, mixed, preequilibrated at 0.25 water activity (aw), ground to achieve homogeneity, reequilibrated, and subjected to isothermal treatment. After enumeration on nonselective differential media, log-linear and Bigelow models were fit to the survivor data via one-step global regression. The aw changes and glass transition temperature were assessed at elevated temperatures by using uninoculated, equilibrated powder samples. Estimated D90°C-values were approximately two times higher for E. faecium (P < 0.05) than for Salmonella in SMP, LP, and MPI, but statistically similar (P > 0.05) in LSMP. Addition of sugars to recovery media did not influence survivor resuscitation from heat-treated SMP and LSMP, confirming that microbial inactivation was impacted primarily by the thermal treatment, not the recovery step. Thermally induced changes in aw were seen only for LP and MPI, with the glass transition temperature observed only for SMP and MPI. In conclusion, rather than always requiring greater lethality of E. faecium than Salmonella, these findings suggest that sufficient pathogen controls for low-moisture foods can also be validated by thoroughly documenting the appropriate kill ratios of E. faecium to Salmonella. HIGHLIGHTS
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Affiliation(s)
- Nurul Hawa Ahmad
- Department of Food Science and Human Nutrition, Michigan State University, East Lansing, Michigan 48824, USA
| | - Bradley P Marks
- Department of Biosystem and Agricultural Engineering, Michigan State University, East Lansing, Michigan 48824, USA
| | - Elliot T Ryser
- Department of Food Science and Human Nutrition, Michigan State University, East Lansing, Michigan 48824, USA
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7
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A comparative study for determination of thermal inactivation parameters of Salmonella in high gel and standard egg white powder using three methods. Lebensm Wiss Technol 2022. [DOI: 10.1016/j.lwt.2022.114185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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8
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Ahmad NH, Hildebrandt IM, Pickens SR, Vasquez S, Jin Y, Liu S, Halik LA, Tsai HC, Lau SK, D'Souza RC, Kumar S, Subbiah J, Thippareddi H, Zhu MJ, Tang J, Anderson NM, Grasso-Kelley EM, Ryser ET, Marks BP. Interlaboratory Evaluation of Enterococcus faecium NRRL B-2354 as a Salmonella Surrogate for Validating Thermal Treatment of Multiple Low-Moisture Foods. J Food Prot 2022; 85:1538-1552. [PMID: 35723555 DOI: 10.4315/jfp-22-054] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 06/16/2022] [Indexed: 11/11/2022]
Abstract
ABSTRACT This multi-institutional study assessed the efficacy of Enterococcus faecium NRRL B-2354 as a nonpathogenic Salmonella surrogate for thermal processing of nonfat dry milk powder, peanut butter, almond meal, wheat flour, ground black pepper, and date paste. Each product was analyzed by two laboratories (five independent laboratories total), with the lead laboratory inoculating (E. faecium or a five-strain Salmonella enterica serovar cocktail of Agona, Reading, Tennessee, Mbandaka, and Montevideo) and equilibrating the product to the target water activity before shipping. Both laboratories subjected samples to three isothermal treatments (between 65 and 100°C). A log-linear and Bigelow model was fit to survivor data via one-step regression. On the basis of D80°C values estimated from the combined model, E. faecium was more thermally resistant (P < 0.05) than Salmonella in nonfat dry milk powder (DEf-80°C, 100.2 ± 5.8 min; DSal-80°C, 28.9 ± 1.0 min), peanut butter (DEf-80°C, 133.5 ± 3.1 min; DSal-80°C, 57.6 ± 1.5 min), almond meal (DEf-80°C, 34.2 ± 0.4 min; DSal-80°C, 26.1 ± 0.2 min), ground black pepper (DEf-80°C, 3.2 ± 0.8 min; DSal-80°C, 1.5 ± 0.1 min), and date paste (DEf-80°C, 1.5 ± 0.0 min; DSal-80°C, 0.5 ± 0.0 min). Although the combined laboratory D80°C for E. faecium was lower (P < 0.05) than for Salmonella in wheat flour (DEf-80°C, 9.4 ± 0.1 min; DSal-80°C, 10.1 ± 0.2 min), the difference was ∼7%. The zT values for Salmonella in all products and for E. faecium in milk powder, almond meal, and date paste were not different (P > 0.05) between laboratories. Therefore, this study demonstrated the impact of standardized methodologies on repeatability of microbial inactivation results. Overall, E. faecium NRRL B-2354 was more thermally resistant than Salmonella, which provides support for utilizing E. faecium as a surrogate for validating thermal processing of multiple low-moisture products. However, product composition should always be considered before making that decision. HIGHLIGHTS
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Affiliation(s)
- Nurul Hawa Ahmad
- Department of Food Science and Human Nutrition, Michigan State University, East Lansing, Michigan 48824
| | - Ian M Hildebrandt
- Department of Biosystems and Agricultural Engineering, Michigan State University, East Lansing, Michigan 48824.,U.S. Food Drug Administration, Institute of Food Safety and Health, 6502 South Archer Road, Bedford Park, Illinois 60501
| | - Shannon R Pickens
- U.S. Food Drug Administration, Institute of Food Safety and Health, 6502 South Archer Road, Bedford Park, Illinois 60501
| | - Sabrina Vasquez
- Department of Food Science and Technology, Institute of Food Safety and Health, 6502 South Archer Road, Bedford Park, Illinois 60501
| | - Yuqiao Jin
- Department of Biological Systems Engineering, Institute of Food Safety and Health, 6502 South Archer Road, Bedford Park, Illinois 60501
| | - Shuxiang Liu
- Department of Biological Systems Engineering, Institute of Food Safety and Health, 6502 South Archer Road, Bedford Park, Illinois 60501
| | - Lindsay A Halik
- Illinois Institute of Technology, Institute of Food Safety and Health, 6502 South Archer Road, Bedford Park, Illinois 60501
| | - Hsieh-Chin Tsai
- School of Food Science, Washington State University, Pullman, Washington 99164
| | - Soon Kiat Lau
- Department of Food Science and Technology, Institute of Food Safety and Health, 6502 South Archer Road, Bedford Park, Illinois 60501.,Department of Biological System Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588
| | - Roshan C D'Souza
- Department of Poultry Science, University of Georgia, Athens, Georgia 30602, USA
| | - Sanjay Kumar
- Department of Poultry Science, University of Georgia, Athens, Georgia 30602, USA
| | - Jeyamkondan Subbiah
- Department of Food Science and Technology, Institute of Food Safety and Health, 6502 South Archer Road, Bedford Park, Illinois 60501.,Department of Biological System Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588
| | | | - Mei-Jun Zhu
- School of Food Science, Washington State University, Pullman, Washington 99164
| | - Juming Tang
- Department of Biological Systems Engineering, Institute of Food Safety and Health, 6502 South Archer Road, Bedford Park, Illinois 60501
| | - Nathan M Anderson
- U.S. Food Drug Administration, Institute of Food Safety and Health, 6502 South Archer Road, Bedford Park, Illinois 60501
| | - Elizabeth M Grasso-Kelley
- U.S. Food Drug Administration, Institute of Food Safety and Health, 6502 South Archer Road, Bedford Park, Illinois 60501
| | - Elliot T Ryser
- Department of Food Science and Human Nutrition, Michigan State University, East Lansing, Michigan 48824
| | - Bradley P Marks
- Department of Biosystems and Agricultural Engineering, Michigan State University, East Lansing, Michigan 48824
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Yang R, Fleischman GJ, Shazer A, Li H. Experimentally Implementing the Linear Nonisothermal Equation for Simultaneously Obtaining D- and z-Values of Salmonella Senftenberg in Skim Milk with a Differential Scanning Calorimeter. J Food Prot 2022; 85:1410-1417. [PMID: 35775995 DOI: 10.4315/jfp-22-009] [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: 01/13/2022] [Accepted: 06/29/2022] [Indexed: 11/11/2022]
Abstract
ABSTRACT For bacteria with log-linear thermal inactivation kinetics in food, D-values are obtained in multiple isothermal inactivation experiments at different temperatures, and the z-value is obtained from these D-values. In a previous work, the cumulative lethality integral was mathematically solved in closed form when temperature in the food increased linearly with time. The solution revealed that each nonisothermal experiment could yield both D- and z-values, eliminating the need for getting multiple D-values to get a z-value. The present study reports on the first experimental implementation of this method of obtaining D- and z-values for Salmonella Senftenberg suspended in skim milk for which a differential scanning calorimeter (DSC) provided the required constant heating rate. The resulting D- and z-values were compared with those obtained from an isothermal method with capillary tubes. No significant differences in z-values were found between the two methods. The D-values also agreed but only after correcting the nonisothermal value for temperature lag in the DSC caused by the large sample size required. A 5 K/min heating rate was used in this comparison. Other rates were also investigated: 1, 3, 7.5, and 10 K/min. Although D- and z-values should be independent of DSC heating rate, heating rates of 1 and 10 K/min yielded values that were significantly different from the others; therefore, these rates cannot be recommended for use in this nonisothermal method. HIGHLIGHTS
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Affiliation(s)
- Ren Yang
- Institute for Food Safety and Health, Illinois Institute of Technology, Bedford Park, Illinois 60501
| | - Gregory J Fleischman
- Institute for Food Safety and Health, Illinois Institute of Technology, Bedford Park, Illinois 60501.,U.S. Food and Drug Administration, Bedford Park, Illinois 60501
| | - Arlette Shazer
- Institute for Food Safety and Health, Illinois Institute of Technology, Bedford Park, Illinois 60501.,U.S. Food and Drug Administration, Bedford Park, Illinois 60501
| | - Haiping Li
- U.S. Department of Agriculture, 1400 Independence Avenue S.W., Washington, DC 20250, USA
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Yang R, Cheng T, Hong Y, Wei L, Tang J. The effect of dry headspace on the thermal resistance of bacteria in peanut oil and peanut butter in thermal treatments. Food Control 2022. [DOI: 10.1016/j.foodcont.2022.108851] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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11
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Xie Y, Zhang S, Sun S, Zhu MJ, Sablani S, Tang J. Survivability of Salmonella and Enterococcus faecium in chili, cinnamon and black pepper powders during storage and isothermal treatments. Food Control 2022. [DOI: 10.1016/j.foodcont.2022.108935] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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12
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Radio frequency assisted thermal processing for pasteurization of packaged whole milk powder surrounded by oil. Food Control 2022. [DOI: 10.1016/j.foodcont.2021.108762] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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13
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Recent development in low-moisture foods: Microbial safety and thermal process. Food Res Int 2022; 155:111072. [DOI: 10.1016/j.foodres.2022.111072] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 02/22/2022] [Accepted: 02/24/2022] [Indexed: 11/17/2022]
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Tong T, Wang P, Shi H, Li F, Jiao Y. Radio frequency inactivation of E. coli O157: H7 and Salmonella Typhimurium ATCC 14028 in black pepper (piper nigrum) kernels: Thermal inactivation kinetic study and quality evaluation. Food Control 2022. [DOI: 10.1016/j.foodcont.2021.108553] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Suehr QJ, Liu X, Grasso-Kelley EM, Anderson NM. Predictive Microbial Modeling of Enterococcus faecium NRRL B-2354 Inactivation during Baking of a Multicomponent Low-Moisture Food. J Food Prot 2021; 84:1990-2001. [PMID: 34189582 DOI: 10.4315/jfp-21-036] [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: 01/26/2021] [Accepted: 06/28/2021] [Indexed: 11/11/2022]
Abstract
ABSTRACT The use of baking ovens as a microbial kill step should be validated based on results of thermal inactivation models. Although traditional isothermal models may not be appropriate for these dynamic processes, they are being used by the food industry. Previous research indicates that the impact of additional process conditions, such as humidity, should be considered when validating thermal processes for the control of microbial hazards in low-moisture foods. In this study, the predictive performance of traditional and modified thermal inactivation kinetic models accounting for process humidity were assessed for predicting inactivation of Enterococcus faecium NRRL B-2354 in a multi-ingredient composite food during baking. Ingredients (milk powder, protein powder, peanut butter, and whole wheat flour) were individually inoculated to achieve ∼6 log CFU/g, equilibrated to a water activity of 0.25, and then mixed to form a cookie dough. An isothermal inactivation study was conducted for the dough to obtain traditional D- and z-values (n = 63). In a separate experiment, cookies were baked under four dynamic heating conditions: 135°C, high humidity; 135°C, low humidity; 150°C, high humidity; and 150°C, low humidity. Process humidity measurements; time-temperature profiles for the product core, surface, and bulk air; and microbial survivor ratios were collected for the four conditions at six residence times (n = 144). The traditional isothermal model had a high root mean square error (RMSE) of 856.51 log CFU/g, significantly overpredicting bacterial inactivation during the process. The modified model accounting for the dynamic time-temperature profile and process humidity data was a better predictor with an RMSE of 0.55 log CFU/g. These results indicate the importance of accounting for additional process parameters in baking inactivation models and that model performance can be improved by utilizing model parameters obtained directly from industrial-scale experimental data. HIGHLIGHTS
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Affiliation(s)
- Quincy J Suehr
- U.S. Food and Drug Administration, Illinois Institute of Technology, Institute for Food Safety and Health, 6502 South Archer Road, Bedford Park, Illinois 60501, USA
| | - Xiyang Liu
- Department of Food Science and Nutrition, Illinois Institute of Technology, Institute for Food Safety and Health, 6502 South Archer Road, Bedford Park, Illinois 60501, USA
| | - Elizabeth M Grasso-Kelley
- Department of Food Science and Nutrition, Illinois Institute of Technology, Institute for Food Safety and Health, 6502 South Archer Road, Bedford Park, Illinois 60501, USA
| | - Nathan M Anderson
- U.S. Food and Drug Administration, Illinois Institute of Technology, Institute for Food Safety and Health, 6502 South Archer Road, Bedford Park, Illinois 60501, USA
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Thermal inactivation of Salmonella, Listeria monocytogenes and Enterococcus faecium NRRL B-2354 in desiccated shredded coconut. Lebensm Wiss Technol 2021. [DOI: 10.1016/j.lwt.2021.111851] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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17
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Dhaliwal HK, Gänzle M, Roopesh MS. Influence of drying conditions, food composition, and water activity on the thermal resistance of Salmonella enterica. Food Res Int 2021; 147:110548. [PMID: 34399525 DOI: 10.1016/j.foodres.2021.110548] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 06/15/2021] [Accepted: 06/16/2021] [Indexed: 10/21/2022]
Abstract
Salmonella contamination of low-water activity (aw) foods poses a serious concern worldwide. The present study was conducted to assess the effects of drying conditions, food composition, and water activity on the desiccation tolerance and thermal resistance of S. Enteritidis FUA1946, S. Senftenberg ATCC43845 and S. Typhimurium ATCC13311 in pet food, binder formulation, and skim milk powder. The samples were wet inoculated with the individual Salmonella strains and were equilibrated to aw 0.33 and 0.75, followed by an isothermal treatment at 70 °C. The thermal inactivation data was fitted to the Weibull model. Irrespective of the aw, food composition and physical structure of the selected foods, strain S. Enteritidis FUA1946 displayed the highest desiccation and thermal resistance, followed by S. Senftenberg ATCC43845 and S. Typhimurium ATCC13311. The food matrix and strain type significantly (p < 0.05) influenced the thermal resistance of microorganisms in foods along with aw change during thermal treatments. To further study the effect of food composition, an additional set of experiments using dry inoculation of the resistant Salmonella strain in the low-aw foods was designed. Significant (p < 0.05) matrix-dependent interaction on Salmonella reduction was observed. The water adsorption isotherms of selected low-aw foods were measured at 20 and 70 °C to relate the thermal inactivation kinetics with the change in the aw. The characterization of thermal resistance of the Salmonella serovars in low-aw products with different compositions and aw in this study may be used for the validation of thermal challenge studies.
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Affiliation(s)
- Harleen Kaur Dhaliwal
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta T6G 2P5, Canada
| | - Michael Gänzle
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta T6G 2P5, Canada
| | - M S Roopesh
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta T6G 2P5, Canada.
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Desiccation and thermal resistance of Salmonella and Enterococcus faecium NRRL B-2354 in almond meal as impacted by water activity and storage temperature. Food Control 2021. [DOI: 10.1016/j.foodcont.2021.108037] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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19
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Thermal inactivation of New Zealand Campylobacter jejuni strains in chicken under dynamic conditions. J FOOD ENG 2021. [DOI: 10.1016/j.jfoodeng.2021.110540] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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20
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Ballom K, Dhowlaghar N, Tsai HC, Yang R, Tang J, Zhu MJ. Radiofrequency pasteurization against Salmonella and Listeria monocytogenes in cocoa powder. Lebensm Wiss Technol 2021. [DOI: 10.1016/j.lwt.2021.111490] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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21
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Cheng T, Tang J, Yang R, Xie Y, Chen L, Wang S. Methods to obtain thermal inactivation data for pathogen control in low-moisture foods. Trends Food Sci Technol 2021. [DOI: 10.1016/j.tifs.2021.03.048] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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22
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Thermal inactivation of Salmonella Enteritidis PT30 in ground cinnamon as influenced by water activity and temperature. Food Control 2021. [DOI: 10.1016/j.foodcont.2021.107935] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Dhowlaghar N, Zhu MJ. Control of Salmonella in low-moisture foods: Enterococcus faecium NRRL B-2354 as a surrogate for thermal and non-thermal validation. Crit Rev Food Sci Nutr 2021; 62:5886-5902. [PMID: 33798006 DOI: 10.1080/10408398.2021.1895055] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Salmonella has been implicated in multiple foodborne outbreaks and recalls associated with low water activity foods (LawF). To verify the effectiveness of a process against Salmonella in LawF, validation using a nonpathogenic surrogate strain is essential. Enterococcus faecium NRRL B-2354 strain has been used as a potential surrogate of Salmonella in different processing of LawF. However, the survival of Salmonella and E. faecium in LawF during food processing is a dynamic function of aw, food composition and structure, processing techniques, and other factors. This review assessed pertinent literature on the thermal and non-thermal inactivation of Salmonella and its presumable surrogate E. faecium in various LawF and provided an overview of its suitibility in different LawF. Overall, based on the D-values, survival/reduction, temperature/time to obtain 4 or 5-log reductions, most studies concluded that E. faecium is a suitable surrogate of Salmonella during LawF processing as its magnitude of resistance was slightly greater or equal (i.e., statistical similar) as compared to Salmonella. Studies also showed its unsuitability which either does not provide a proper margin of safety or being overly resistant and may compromise the quality and organoleptic properties of food. This review provides useful information and guidance for future validation studies of LawF.
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Affiliation(s)
- Nitin Dhowlaghar
- School of Food Science, Washington State University, Pullman, Washington, USA
| | - Mei-Jun Zhu
- School of Food Science, Washington State University, Pullman, Washington, USA
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Lau SK, Wei X, Kirezi N, Panth R, See A, Subbiah J. A Comparison of Three Methods for Determining Thermal Inactivation Kinetics: A Case Study on Salmonella enterica in Whole Milk Powder. J Food Prot 2021; 84:521-530. [PMID: 33159446 DOI: 10.4315/jfp-20-232] [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: 06/12/2020] [Accepted: 10/30/2020] [Indexed: 11/11/2022]
Abstract
ABSTRACT Different methods for determining the thermal inactivation kinetics of microorganisms can result in discrepancies in thermal resistance values. In this study, thermal resistance of Salmonella in whole milk powder was determined with three methods: thermal death time (TDT) disk in water bath, pouches in water bath, and the TDT Sandwich system. Samples from three production lots of whole milk powder were inoculated with a five-strain Salmonella cocktail and equilibrated to a water activity of 0.20. The samples were then subjected to three isothermal treatments at 75, 80, or 85°C. Samples were removed at six time points and cultures were enumerated for survivors. The inactivation data were fitted to two consolidated models: two primary models (log linear and Weibull) and one secondary model (Bigelow). Normality testing indicated that all the model parameters were normally distributed. None of the model parameters for both consolidated models were significantly different (α = 0.05). The amount of inactivation during the come-up time was also not significantly different among the methods (α = 0.05). However, the TDT Sandwich resulted in less inactivation during the come-up time and overall less variation in model parameters. The survivor data from all three methods were combined and fitted to both consolidated models. The Weibull had a lower root mean square error and a better fit, according to the corrected Akaike's information criterion. The three thermal treatment methods produced results that were not significantly different; thus, the methods are interchangeable, at least for Salmonella in whole milk powder. Comparisons with more methods, other microorganisms, and larger varieties of food products using the same framework presented in this study could provide guidance for standardizing thermal inactivation kinetics studies for microorganisms in foods. HIGHLIGHTS
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Affiliation(s)
- Soon Kiat Lau
- Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, Nebraska 68588 (ORCID: https://orcid.org/0000-0001-8264-7761 [S.K.L.]; https://orcid.org/0000-0002-1746-2653 [X.W.]; https://orcid.org/0000-0002-8512-0735 [J.S.]).,Department of Biological Systems Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68583
| | - Xinyao Wei
- Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, Nebraska 68588 (ORCID: https://orcid.org/0000-0001-8264-7761 [S.K.L.]; https://orcid.org/0000-0002-1746-2653 [X.W.]; https://orcid.org/0000-0002-8512-0735 [J.S.])
| | - Nina Kirezi
- Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, Nebraska 68588 (ORCID: https://orcid.org/0000-0001-8264-7761 [S.K.L.]; https://orcid.org/0000-0002-1746-2653 [X.W.]; https://orcid.org/0000-0002-8512-0735 [J.S.])
| | - Rajendra Panth
- Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, Nebraska 68588 (ORCID: https://orcid.org/0000-0001-8264-7761 [S.K.L.]; https://orcid.org/0000-0002-1746-2653 [X.W.]; https://orcid.org/0000-0002-8512-0735 [J.S.])
| | - Arena See
- Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, Nebraska 68588 (ORCID: https://orcid.org/0000-0001-8264-7761 [S.K.L.]; https://orcid.org/0000-0002-1746-2653 [X.W.]; https://orcid.org/0000-0002-8512-0735 [J.S.])
| | - Jeyamkondan Subbiah
- Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, Nebraska 68588 (ORCID: https://orcid.org/0000-0001-8264-7761 [S.K.L.]; https://orcid.org/0000-0002-1746-2653 [X.W.]; https://orcid.org/0000-0002-8512-0735 [J.S.]).,Department of Biological Systems Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68583.,Department of Food Science, University of Arkansas, System Division of Agriculture, Fayetteville, Arkansas 72704, USA
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25
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Wei X, Vasquez S, Thippareddi H, Subbiah J. Evaluation of Enterococcus faecium NRRL B-2354 as a surrogate for Salmonella in ground black pepper at different water activities. Int J Food Microbiol 2021; 344:109114. [PMID: 33652336 DOI: 10.1016/j.ijfoodmicro.2021.109114] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 01/08/2021] [Accepted: 02/14/2021] [Indexed: 10/22/2022]
Abstract
Thermal inactivation kinetics of Salmonella in low moisture foods are necessary for developing proper thermal processing parameters for pasteurization. The effect of water activity on thermal inactivation kinetics of Salmonella and Enterococcus faecium NRRL B-2354 in ground black pepper has not been studied previously. Identification of a suitable surrogate assists in conducting in-plant process validations. Ground black pepper was inoculated with a 5-serotype Salmonella cocktail or E. faecium NRRL B-2354, equilibrated to water activities of 0.25, 0.45 or 0.65 in a humidity-controlled chamber, and isothermally treated at different temperatures. The survivor data were used for fitting the log-linear models to obtain the D and z-values of Salmonella and E. faecium in ground black pepper. Modified Bigelow models were developed to evaluate the effects of temperature and water activity on the thermal inactivation kinetics of Salmonella and E. faecium. Water activity and temperature showed significant negative effects on the thermal resistance of Salmonella and E. faecium in ground black pepper. For example, significantly higher D values of Salmonella were observed at water activity of 0.45 (D70°C = 20.5 min and D75°C = 7.8 min) compared to water activity of 0.65 (D70°C = 3.9 min and D75°C = 2.0 min). D-values of E. faecium were significantly higher than those of Salmonella at all three water activities, indicating that E. faecium is a suitable surrogate for Salmonella in thermal processing validation.
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Affiliation(s)
- Xinyao Wei
- Department of Food Science and Technology, University of Nebraska-Lincoln, NE, USA
| | - Sabrina Vasquez
- Department of Food Science and Technology, University of Nebraska-Lincoln, NE, USA
| | | | - Jeyamkondan Subbiah
- Department of Food Science and Technology, University of Nebraska-Lincoln, NE, USA; Department of Food Science, University of Arkansas System Division of Agriculture, Fayetteville, AR, USA.
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26
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Al-Sakkaf A. Thermal inactivation and kinetic parameters for Campylobacter jejuni on chicken skin. Can J Microbiol 2021; 67:623-638. [PMID: 33529082 DOI: 10.1139/cjm-2020-0543] [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] [Indexed: 11/22/2022]
Abstract
New Zealand has a higher reported incidence rate of campylobacteriosis than other developed countries. It has been suggested that this may be due to the emergence of heat-resistant strains that can survive normal cooking. To test this, typed Campylobacter strains ST474 and ST48 were inoculated onto slices of chicken skin <18 mm in diameter and 4 mm thick using a pipette, and placed in a special aluminium cell, which was heated to a predetermined temperature (in the range of 56.5 to 65 °C) using a temperature-controlled water bath. Survivor curves were plotted, and GlnaFit software was chosen to fit the experimental data; inactivation parameters were estimated using 1-step and 2-step regression. The D values and z values were in the range of 3-6 s and 8-11 °C, respectively. The D values at 60 and 56 °C were in the range of 12-41 s. These D values are in general agreement with previously published reports. Thus, New Zealand's higher reported rate of campylobacteriosis is possibly due to factors other than the emergence of heat-resistant strains.
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Affiliation(s)
- Ali Al-Sakkaf
- Institute of Food, Nutrition and Human Health, Massey University, Palmerston North 4442, New Zealand.,Institute of Food, Nutrition and Human Health, Massey University, Palmerston North 4442, New Zealand
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27
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Effects of radio frequency on physicochemical properties of powdered infant formula milk as compared with conventional thermal treatment. Lebensm Wiss Technol 2020. [DOI: 10.1016/j.lwt.2020.110194] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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28
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Lau SK, Subbiah J. TDT Sandwich: An open source dry heat system for characterizing the thermal resistance of microorganisms. HARDWAREX 2020; 8:e00114. [PMID: 35498246 PMCID: PMC9041244 DOI: 10.1016/j.ohx.2020.e00114] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 04/03/2020] [Accepted: 06/04/2020] [Indexed: 06/14/2023]
Abstract
The determination of the thermal death kinetics of microorganisms has traditionally been performed with liquid baths which have some disadvantages such as liquid spillage and liquid infiltration into samples. The TDT Sandwich was developed as a free, open source alternative that utilizes dry heat. The system is capable of heating samples up to 140 °C and maintaining it within 0.2 °C of the target temperature. Other features of the TDT Sandwich include adjustable heating rates up to approximately 100 °C/min, real-time display and recording of temperature readings at a nominal rate of 5 Hz, an optional thermocouple for acquiring temperature of samples, built-in heating timer, and customizable operating parameters. The modular nature of the TDT Sandwich allows multiple units to be connected to a computer or laptop. Operation of the TDT Sandwich is done through a computer program which, along with the build instructions and microcontroller program, are open source and are available for free to the public at https://doi.org/10.17605/OSF.IO/5Q3Y7.
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Affiliation(s)
- Soon Kiat Lau
- Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, NE, USA
- Department of Biological Systems Engineering, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Jeyamkondan Subbiah
- Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, NE, USA
- Department of Biological Systems Engineering, University of Nebraska-Lincoln, Lincoln, NE, USA
- Department of Food Science, University of Arkansas, Fayetteville, AR, USA
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29
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Zhu M, Song X, Shen X, Tang J. Listeria monocytogenes in Almond Meal: Desiccation Stability and Isothermal Inactivation. Front Microbiol 2020; 11:1689. [PMID: 32849354 PMCID: PMC7427469 DOI: 10.3389/fmicb.2020.01689] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 06/29/2020] [Indexed: 01/11/2023] Open
Abstract
Almond are among the most consumed tree nuts and used in a variety of food products. Recent almond butter recalls due to potential contamination of Listeria monocytogenes highlight the need to control L. monocytogenes in almond products. The objectives of this study were to examine the stability of L. monocytogenes in almond meal during extended storage and analyze thermal resistance of L. monocytogenes in almond meal of controlled moisture contents or water activity (aw) using thermal death time (TDT) cells and thermal water activity (TWA) cells, respectively. L. monocytogenes maintained a stable population in almond meal for 44–48 weeks at 4°C regardless of aw; however, we observed about 1.69 and 2.14 log10 colony-forming units (CFU)/g reduction of L. monocytogenes in aw 0.25 and 0.45 almond meal over 44 to 48 weeks of storage at 22°C. Under all test conditions using either TDT or TWA cells, the inactivation kinetics of L. monocytogenes in almond meal fitted the log-linear model well; thermal resistance of L. monocytogenes in almond meal was inversely related to the aw of samples. D75-/D80-values of L. monocytogenes in aw 0.25 and 0.45 almond meal obtained using TDT cells were 47.6/22.0 versus 17.2/11.0 min, respectively. D80-, D85-, and D90-values of L. monocytogenes in aw 0.25 almond meal obtained using TWA cells were 59.5 ± 2.1, 27.7 ± 0.7, and 13.2 ± 1.1 min, respectively, in contrast to 22.0 ± 1.1, 10.6 ± 0.2, and 4.6 ± 0.4 min obtained using TDT cells. The z-value of L. monocytogenes in aw 0.25 almond meal was not affected by TWA and TDT cell type (15.4–15.5°C), whereas z-value of L. monocytogenes in aw 0.45 almond meal was 10°C higher than that in aw 0.25 almond meal. This study contributes to our understanding of L. monocytogenes in nuts and impacts of aw on the development of thermal resistance in low-moisture foods.
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Affiliation(s)
- Meijun Zhu
- School of Food Science, Washington State University, Pullman, WA, United States
| | - Xia Song
- School of Food Science, Washington State University, Pullman, WA, United States
| | - Xiaoye Shen
- School of Food Science, Washington State University, Pullman, WA, United States
| | - Juming Tang
- Department of Biological Systems Engineering, Washington State University, Pullman, WA, United States
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30
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Gautam B, Govindan BN, Gӓnzle M, Roopesh MS. Influence of water activity on the heat resistance of Salmonella enterica in selected low-moisture foods. Int J Food Microbiol 2020; 334:108813. [PMID: 32841809 DOI: 10.1016/j.ijfoodmicro.2020.108813] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2019] [Revised: 04/23/2020] [Accepted: 08/01/2020] [Indexed: 10/23/2022]
Abstract
Low-moisture foods (LMF with water activity, aw < 0.85) including pet foods and black pepper powder have consistently been associated with foodborne disease caused by Salmonella enterica. Increased heat resistance and prolonged survival at low-moisture conditions, however, remain major challenges to achieve effective inactivation of Salmonella in low-moisture foods. At low water activity (aw) conditions, heat resistance of Salmonella is greatly enhanced when compared to high aw conditions. This study aimed to quantify the effect of aw on the heat resistance of Salmonella enterica in pet food pellets and black pepper powder. Pet food pellets were inoculated with two strains of heat resistant S. enterica and black pepper powder was inoculated with a 5-strain cocktail of Salmonella. Both inoculated food samples were equilibrated at 0.33, 0.54, and 0.75 aw in controlled humidity chambers. Inoculated pet food pellets and black pepper powder in closed aluminum cells were heat treated at specific temperatures for selected times. The results showed that the Weibull model fitted well the inactivation data. At a specific temperature, the rate of inactivation increased with the increase in the aw from 0.33 to 0.75, and the 3-log reduction times decreased for Salmonella in both food samples with the increase in aw. Water adsorption isotherms of pet food pellets and black pepper powder at initial and treatment temperatures were developed to understand the change in aw during heat treatments. The change in aw during heat treatment was dependent on the type of food matrix, which possibly influenced the thermal inactivation of Salmonella in pet food pellets and black pepper powder. The quantitative analysis of heat reduction of Salmonella with respect to aw aids in selection of the appropriate initial aw to develop effective heat treatment protocols for adequate reduction of Salmonella in pet foods and black pepper powder.
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Affiliation(s)
- Bina Gautam
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta T6G 2P5, Canada
| | - Byju N Govindan
- Department of Entomology, University of Minnesota, 1980 Folwell Avenue, 219 Hodson Hall, St. Paul, MN 55108, USA
| | - Michael Gӓnzle
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta T6G 2P5, Canada
| | - M S Roopesh
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta T6G 2P5, Canada.
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31
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Zhang Y, Xie Y, Tang J, Wang S, Wang L, Zhu G, Li X, Liu Y. Thermal inactivation of Cronobacter sakazakii ATCC 29544 in powdered infant formula milk using thermostatic radio frequency. Food Control 2020. [DOI: 10.1016/j.foodcont.2020.107270] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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32
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Pérez-Reyes ME, Jie X, Zhu MJ, Tang J, Barbosa-Cánovas GV. Influence of low water activity on the thermal resistance of Salmonella Enteritidis PT30 and Enterococcus faecium as its surrogate in egg powders. FOOD SCI TECHNOL INT 2020; 27:184-193. [DOI: 10.1177/1082013220937872] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Egg powders are increasingly popular ingredients, due to their functionality and compactness, in industrial food production and preparation at homes. However, there is a lack of studies that evaluate the thermal resistance of Salmonella Enteritidis PT30 and its potential surrogate Enterococcus faecium NRRL B-2354 in egg powders. This study examined the log-linear relationship between the thermal resistance of Salmonella Enteritidis (D-value) and the water activity (aw) of egg powders. The changes of aw in the egg powders with temperature were measured using a Vapor Sorption Analyzer and a high-temperature cell. The D80 ℃-value of S. Enteritidis PT30 and E. faecium inoculated in the egg powders preconditioned to three aw levels (0.3, 0.45, and 0.6) at 20 ℃ were determined using aluminum thermal death test cells. The aw values increased (P < 0.05) in all three egg powders when the temperature of the samples was raised from room temperature to 80 ℃. The D80 ℃-values ranged from 5.3 ± 0.1 to 25.9 ± 0.2 min for S. Enteritidis while 10.4 ± 0.4 to 43.8 ± 0.4 for E. faecium in samples of the three different aw levels. S. Enteritidis PT30 showed a log-linear relationship between D80 ℃-values and aw80 ℃ for the egg powders. This study contributes to our understanding of the impact of aw on the development of thermal treatments for low-moisture foods.
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Affiliation(s)
- Marco E Pérez-Reyes
- Department of Biological Systems Engineering, Washington State University, Pullman, WA, USA
| | - Xu Jie
- Department of Biological Systems Engineering, Washington State University, Pullman, WA, USA
| | - Mei-Jun Zhu
- School of Food Science, Washington State University, Pullman, WA, USA
| | - Juming Tang
- Department of Biological Systems Engineering, Washington State University, Pullman, WA, USA
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33
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Stability of Listeria monocytogenes in non-fat dry milk powder during isothermal treatment and storage. Food Microbiol 2020; 87:103376. [DOI: 10.1016/j.fm.2019.103376] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 09/17/2019] [Accepted: 11/12/2019] [Indexed: 02/06/2023]
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34
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Hildebrandt IM, Marks BP, Anderson NM, Grasso-Kelley EM. Reproducibility of Salmonella Thermal Resistance Measurements via Multilaboratory Isothermal Inactivation Experiments. J Food Prot 2020; 83:609-614. [PMID: 32221564 DOI: 10.4315/0362-028x.jfp-19-343] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 12/03/2019] [Indexed: 11/11/2022]
Abstract
ABSTRACT Isothermal inactivation experiments often are used to investigate the thermal resistance of pathogens, such as Salmonella, in foods; however, little is known about the reproducibility of such experimental methodologies. The objective of this study was to quantify the reproducibility of Salmonella isothermal resistance results via a six-laboratory comparison. Inoculation was performed at a single location and then distributed to each laboratory for isothermal analysis. Salmonella Agona 447967 was inoculated into oat flour, re-equilibrated to a water activity (aw) of 0.45, and then packaged and distributed to each laboratory. Before conducting the inactivation trials, each laboratory was required to verify the inoculated product's aw, enumerate Salmonella population levels, and verify that the isothermal treatment medium was at the target temperature (80°C). All laboratories were required to process at least three replications, collect at least six sample time points with three subsamples at each sampling point, enumerate survivors using an identical plating methodology and media, and verify that the temperature did not substantially change during isothermal treatment. The log-linear model was fit to the Salmonella survivor data, and the resultant D-values were statistically compared via Welch's t test (α = 0.05). Two significant differences in thermal inactivation kinetics were identified as potentially resulting from suspected methodology deviations. Two of the inoculated batches distributed for analysis yielded significantly lower D-values, which likely resulted from a deviation in the inoculation procedures. One laboratory yielded significantly lower D-values, which was likely the result of temperature deviations. Overall, excluding the D-values resulting from deviations, the inactivation results were reproducible, yielding D-values of 30.2 ± 3 min. These results indicate that isothermal inactivation results can be reproducible but that even minor methodology deviations can substantially affect measured Salmonella thermal resistance. HIGHLIGHTS
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Affiliation(s)
- Ian M Hildebrandt
- U.S. Food and Drug Administration, 6502 South Archer Road, Bedford Park, Illinois 60501
| | - Bradley P Marks
- Department of Biosystems and Agricultural Engineering, Michigan State University, East Lansing, Michigan 43824
| | - Nathan M Anderson
- U.S. Food and Drug Administration, 6502 South Archer Road, Bedford Park, Illinois 60501
| | - Elizabeth M Grasso-Kelley
- Department of Food Science and Nutrition/Institute for Food Safety and Health, Illinois Institute of Technology, 6502 South Archer Road, Bedford Park, Illinois 60501, USA
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35
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Xu J, Shah DH, Song J, Tang J. Changes in cellular structure of heat-treated Salmonella in low-moisture environments. J Appl Microbiol 2020; 129:434-442. [PMID: 32052556 DOI: 10.1111/jam.14614] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 01/14/2020] [Accepted: 02/08/2020] [Indexed: 11/28/2022]
Abstract
AIMS Salmonella cells desiccated in an environment with low-water activity (aw ) show longer survival times and enhanced resistance to heat. However, little is known about the cellular ultrastructure of Salmonella in low-aw environment in relation to the survival and persistence during desiccation. MATERIALS AND RESULTS In this study, Salmonella Enteritidis strain PT30 was dehydrated by exposure to air or by mixing with wheat flour (aw 0·30 at room temperature) for 7 days followed by heat treatment at 80°C for 10, 20, 60 min respectively. Transmission electron microscopy (TEM) was employed to examine and compare the ultrastructure of heat-treated S. Enteritidis cells after desiccation with the cells suspended in trypticase soy broth (TSB). Cells suspended in TSB broth showed disrupted ribosomes, congregated proteins and denatured DNA. However, no significant alterations were observed in the ultrastructure of the desiccated cells after heat treatment. The number of desiccated S. Enteritidis cells decreased by <1·5 log CFU per gram after 80°C treatment for 60 min, however, cells suspended in TSB declined more than 5 log10 CFU per mL at 80°C within 5 min. CONCLUSIONS A drastic difference in the number of survivors and cellular ultrastructure was observed between vegetative and air or food-dried S. Enteritidis cells after subjecting to heat treatment at 80°C. No significant ultrastructure changes were observed in desiccated cells after heat treatment except for roughening and corrugating surfaces. SIGNIFICANCE AND IMPACT OF THE STUDY This study provides a direct comparison to illustrate how desiccation influences the cell ultrastructure before/after heat treatment, which will aid in better understanding of the fundamental mechanism underlying the increased thermal resistance of Salmonella cells in low-aw environment.
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Affiliation(s)
- J Xu
- Department of Biological Systems Engineering, Washington State University, Pullman, WA, USA
| | - D H Shah
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA, USA
| | - J Song
- The Affiliated Hospital of Qingdao University, Qingdao, Shandong, China
| | - J Tang
- Department of Biological Systems Engineering, Washington State University, Pullman, WA, USA
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36
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Evaluation of Enterococcus faecium NRRL B-2354 as a potential surrogate of Salmonella in packaged paprika, white pepper and cumin powder during radio frequency heating. Food Control 2020. [DOI: 10.1016/j.foodcont.2019.106833] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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37
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Muramatsu Y, Dolan KD, Mishra DK. Factors influencing estimation of thermal inactivation parameters in low-moisture foods using a test cell. J FOOD ENG 2019. [DOI: 10.1016/j.jfoodeng.2019.05.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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38
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Verheyen D, Baka M, Akkermans S, Skåra T, Van Impe JF. Effect of microstructure and initial cell conditions on thermal inactivation kinetics and sublethal injury of Listeria monocytogenes in fish-based food model systems. Food Microbiol 2019; 84:103267. [DOI: 10.1016/j.fm.2019.103267] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 05/22/2019] [Accepted: 07/10/2019] [Indexed: 01/07/2023]
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39
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Improved design of aluminum test cell to study the thermal resistance of Salmonella enterica and Enterococcus faecium in low-water activity foods. Food Control 2019. [DOI: 10.1016/j.foodcont.2019.05.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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40
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Campylobacter heat resistance - past, current status and future prospect for New Zealand and beyond. WORLD POULTRY SCI J 2019. [DOI: 10.1017/s0043933915000100] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Tsai HC, Ballom KF, Xia S, Tang J, Marks BP, Zhu MJ. Evaluation of Enterococcus faecium NRRL B-2354 as a surrogate for Salmonella during cocoa powder thermal processing. Food Microbiol 2019; 82:135-141. [DOI: 10.1016/j.fm.2019.01.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Revised: 01/07/2019] [Accepted: 01/11/2019] [Indexed: 10/27/2022]
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Thermal resistance of Listeria monocytogenes in natural unsweetened cocoa powder under different water activity. Food Control 2019. [DOI: 10.1016/j.foodcont.2019.03.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Ozturk S, Liu S, Xu J, Tang J, Chen J, Singh RK, Kong F. Inactivation of Salmonella Enteritidis and Enterococcus faecium NRRL B-2354 in corn flour by radio frequency heating with subsequent freezing. Lebensm Wiss Technol 2019. [DOI: 10.1016/j.lwt.2019.04.090] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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de Souza Figueiredo EE, Yang X, Zhang P, Reuter T, Stanford K. Comparison of heating block and water bath methods to determine heat resistance in Shiga-toxin producing Escherichia coli with and without the locus of heat resistance. J Microbiol Methods 2019; 164:105679. [PMID: 31351872 DOI: 10.1016/j.mimet.2019.105679] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 07/24/2019] [Accepted: 07/24/2019] [Indexed: 10/26/2022]
Abstract
This study found variability in the time required for tubes of media in heating block wells to reach 60 °C, resulting in significant effects on heat resistance measurements. To determine the extent that methodology changed heat resistance measurements, we compared the heat resistance of Shiga-toxin producing Escherichia coli (STEC) strains with and without the locus of heat resistance (LHR) using both heating block and water bath methods. A total of 34 strains of STEC were used along with a generic E. coli which has been identified as heat-resistant and used as a positive control. The E. coli strains were incubated in a water bath and a heating block set at 60 °C to determine come up time to 60 °C (T0) and for 6 additional minutes (T6) to calculate the D60 value. After incubation, the colony forming units (CFU) were enumerated and mean log CFU/mL from biological replicates was calculated. To compare reductions from T0 to T6, standard deviations among replicates within heating method and correlation of the D60 values generated across methods were determined using Mixed model and Correlation analyses. Our findings indicate that the method chosen to evaluate heat resistance of E. coli can dramatically influence results as there was not a significant correlation between D60 values for the same isolate determined by water bath and heating block methods. The water bath method generates more reliable and consistent heat resistance data and should be used in future evaluations of heat resistance in E. coli. Moreover, PCR screening for the LHR would only be moderately useful for predicting phenotypic heat-resistance of E. coli. Considering water bath data only, LHR-positive STEC isolates were either moderately heat-resistant (1 to 5 log reduction) or heat-sensitive (> 5 log reduction). As LHR-negative STEC were also moderately heat-resistant, prediction of phenotypic heat resistance from genotype requires further refinement.
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Affiliation(s)
| | - Xianqin Yang
- Agriculture and Agri-Food Canada, Lacombe Research and Development Centre, Lacombe, AB T4L 1W1, Canada
| | - Peipei Zhang
- Agriculture and Agri-Food Canada, Lacombe Research and Development Centre, Lacombe, AB T4L 1W1, Canada
| | - Tim Reuter
- Alberta Agriculture and Forestry, Agriculture Centre, Lethbridge, AB T1J 4V6, Canada
| | - Kim Stanford
- Alberta Agriculture and Forestry, Agriculture Centre, Lethbridge, AB T1J 4V6, Canada.
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Ahmad NH, Öztabak C, Marks BP, Ryser ET. Effect of Talc as a Dry-Inoculation Carrier on Thermal Resistance of Enterococcus faecium NRRL B-2354 in Almond Meal. J Food Prot 2019; 82:1110-1115. [PMID: 31210547 DOI: 10.4315/0362-028x.jfp-18-543] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
HIGHLIGHTS E. faecium was more thermally resistant in dry- than in wet-inoculated almond meal. Presence of talc affected thermal resistance of E. faecium in almond meal. Use of dry inoculum carriers for thermal validation studies requires further work.
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Affiliation(s)
- Nurul Hawa Ahmad
- 1 Department of Food Science and Human Nutrition, Michigan State University, 469 Wilson Road, East Lansing, Michigan 48824, USA (ORCID: https://orcid.org/0000-0003-1337-2658 [E.T.R.])
| | - Cemre Öztabak
- 2 Sakarya University, Esentepe Campus, Serdivan, Sakarya, Turkey 54187
| | - Bradley P Marks
- 3 Department of Biosystems and Agricultural Engineering, Michigan State University, East Lansing, Michigan 48824, USA
| | - Elliot T Ryser
- 1 Department of Food Science and Human Nutrition, Michigan State University, 469 Wilson Road, East Lansing, Michigan 48824, USA (ORCID: https://orcid.org/0000-0003-1337-2658 [E.T.R.])
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Xu J, Tang J, Jin Y, Song J, Yang R, Sablani SS, Zhu MJ. High temperature water activity as a key factor influencing survival of Salmonella Enteritidis PT30 in thermal processing. Food Control 2019. [DOI: 10.1016/j.foodcont.2018.11.054] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Kou X, Li R, Zhang L, Ramaswamy H, Wang S. Effect of heating rates on thermal destruction kinetics of Escherichia coli ATCC25922 in mashed potato and the associated changes in product color. Food Control 2019. [DOI: 10.1016/j.foodcont.2018.10.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Liu S, Xu J, Xie L, Zhu MJ, Tang J. Dry inoculation methods for nonfat milk powder. J Dairy Sci 2019; 102:77-86. [DOI: 10.3168/jds.2018-14478] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 09/10/2018] [Indexed: 11/19/2022]
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Auksornsri T, Bornhorst ER, Tang J, Tang Z, Songsermpong S. Developing model food systems with rice based products for microwave assisted thermal sterilization. Lebensm Wiss Technol 2018. [DOI: 10.1016/j.lwt.2018.05.054] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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