1
|
Geng Z, Ye P, Zhou L, Fu H, Chen X, Wang Y, Wang Y. Pasteurization of Salmonella spp. in black fungus ( Auricularia auricula) powder by radio frequency heating. FOOD SCI TECHNOL INT 2024; 30:3-17. [PMID: 36065562 DOI: 10.1177/10820132221123437] [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] [Indexed: 11/16/2022]
Abstract
Radio frequency (RF) heating has been studied to inactivate bacteria in some powder foods. In this study, a 6 kW, 27.12 MHz RF system was used to pasteurize Salmonella in black fungus (Auricularia auricula) powder. The effects of different conditions (initial aw, electrodes gaps, particle sizes) on RF heating rate and uniformity were investigated. The results showed that RF heating rate was significantly (p < 0.05) improved with decreasing electrodes gap and increasing initial aw, and the heating rate was the slowest when the particle size was 120-160 mesh. However, these factors had no significant (p > 0.05) influence on heating uniformity. RF pasteurization of Salmonella in black fungus powder was also studied. The results showed that, to inactivate Salmonella for 5 log reductions in the cold spot (the center of surface layer), the time needed and bacteria heat resistance at designated temperature (65, 75, 85 °C) decreased with increasing aw, and the first order kinetics and Weibull model could be used to fit inactivation curves of Salmonella with well goodness. Quality analysis results showed that although RF pasteurization had no significant (p > 0.05) effect on Auricularia auricula polysaccharide (AAP) and total polyphenols, obvious changes were found on color. Results suggested that RF pasteurization can be considered as an effective pasteurization method for black fungus powder.
Collapse
Affiliation(s)
- Zheng Geng
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, China
| | - Pengfei Ye
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, China
| | - Liangfu Zhou
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, China
| | - Hongfei Fu
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, China
| | - Xiangwei Chen
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, China
| | - Yequn Wang
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, China
| | - Yunyang Wang
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, China
| |
Collapse
|
2
|
Chen Q, Wu T, Morgan MT, Chen J. Quality analysis of a
ll‐purpose
wheat flour pasteurized with
radiofrequency‐assisted
hot air heating. J FOOD PROCESS ENG 2022. [DOI: 10.1111/jfpe.14104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Qianyi Chen
- Department of Food Science University of Tennessee Knoxville Tennessee USA
| | - Tao Wu
- Department of Food Science University of Tennessee Knoxville Tennessee USA
| | - Mark T. Morgan
- Department of Food Science University of Tennessee Knoxville Tennessee USA
| | - Jiajia Chen
- Department of Food Science University of Tennessee Knoxville Tennessee USA
| |
Collapse
|
3
|
Impact of radio frequency treatment on textural properties of food products: An updated review. Trends Food Sci Technol 2022. [DOI: 10.1016/j.tifs.2022.04.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
4
|
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]
|
5
|
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]
|
6
|
Metabolic Responses of "Big Six" Escherichia coli in Wheat Flour to Thermal Treatment Revealed by Nuclear Magnetic Resonance Spectroscopy. Appl Environ Microbiol 2022; 88:e0009822. [PMID: 35285244 DOI: 10.1128/aem.00098-22] [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] [Indexed: 01/13/2023] Open
Abstract
Escherichia coli outbreaks linked to wheat flour consumption have kept emerging in recent years, which necessitated an antimicrobial step being incorporated into the flour production process. The objectives of this in vivo study were to holistically evaluate the sanitizing efficacy of thermal treatment at 60 and 70°C against the "big six" E. coli strains (O26:H11, O45:H2, O103:H11, O111, O121:H19, and O145) in wheat flour and to assess the strain-specific metabolic responses using nuclear magnetic resonance (NMR) spectroscopy. The 70°C treatment temperature indiscriminatingly inactivated all strains by over 4.3-log CFU/g within 20 min, suggesting the high sanitization effectiveness of this treatment temperature, whereas the treatment at 60°C inactivated the strains to various degrees during the 1-h process. The most resistant strains at 60°C, O26 and O45, were characterized by amino acid and sugar depletion, and their high resistance was attributed to the dual effects of activated heat shock protein (HSP) synthesis and promoted glycolysis. O121 also demonstrated these metabolic changes, yet its thermal resistance was largely impaired by the weakened membrane structure and diminished osmotic protection due to phosphorylcholine exhaustion. In contrast, O111, O145, and O103 presented a substantial elevation of metabolites after stress at 60°C; their moderate thermal resistance was mainly explained by the accumulation of amino acids as osmolytes. Overall, the study enhanced our understanding of the metabolic responses of big six E. coli to heat stress and provided a model for conducting NMR-based metabolomic studies in powdered food matrices. IMPORTANCE "Big six" Escherichia coli strains have caused several outbreaks linked to wheat flour consumption in the last decade, revealing the vital importance of adopting an antimicrobial treatment during the flour production process. Therefore, the present study was carried out to evaluate the efficacy of a typical sanitizing approach, thermal treatment, against the big six strains in wheat flour along with the underlying antimicrobial mechanisms. Findings showed that thermal treatment at 60 and 70°C could markedly mitigate the loads of all strains in wheat flour. Moreover, activated heat shock protein synthesis combined with expedited glycolysis and enhanced osmotic protection were identified as two major metabolic alteration patterns in the E. coli strains to cope with the heat stress. With the responses of big six in wheat flour to thermal treatment elucidated, scientific basis for incorporating a thermal inactivation step in wheat flour production was provided.
Collapse
|
7
|
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]
|
8
|
Liu S, Wei X, Tang J, Qin W, Wu Q. Recent developments in low-moisture foods: microbial validation studies of thermal pasteurization processes. Crit Rev Food Sci Nutr 2021:1-16. [PMID: 34927484 DOI: 10.1080/10408398.2021.2016601] [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: 10/19/2022]
Abstract
Outbreaks associated with low-moisture foods (e.g., wheat flour, nuts, and cereals) have urged the development of novel technologies and re-validation of legacy pasteurization process. For various thermal pasteurization processes, they share same scientific facts (e.g., bacterial heat resistance increased at reduced water activity) and guidelines. However, they also face specific challenges because of their different heat transfer mechanisms, processing conditions, or associated low-moisture foods' formulations. In this article, we first introduced the general structural for validating a thermal process and the shared basic information that would support our understanding of the key elements of each thermal process. Then, we reviewed the current progress of validation studies of 7 individual heating technologies (drying roasting, radiofrequency-assisted pasteurization, superheated steam, etc.) and the combined treatments (e.g., infrared and hot air). Last, we discussed knowledge gaps that require more scientific data in the future studies. We aimed to provide a process-centric view point of thermal pasteurization studies of low-moisture foods. The information could provide detailed protocol for process developers, operators, and managers to enhance low-moisture foods safety.
Collapse
Affiliation(s)
- Shuxiang Liu
- 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, China.,Institute of Food Processing and Safety, School of Food Science, Sichuan Agricultural University, Sichuan, China
| | - Xinyao Wei
- College of Biological Science and Engineering, Fuzhou University, Fuzhou, China
| | - Juming Tang
- Department of Biological Systems Engineering, Washington State University, Pullman, WA, USA
| | - Wen Qin
- Institute of Food Processing and Safety, School of Food Science, Sichuan Agricultural University, Sichuan, 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, China
| |
Collapse
|
9
|
Guan X, Lin B, Xu Y, Yang G, Xu J, Zhang S, Li R, Wang S. Recent developments in pasteurising seeds and their products using radio frequency heating: a review. Int J Food Sci Technol 2021. [DOI: 10.1111/ijfs.15497] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Xiangyu Guan
- College of Mechanical and Electronic Engineering Northwest A&F University Yangling Shaanxi 712100 China
| | - Biying Lin
- College of Mechanical and Electronic Engineering Northwest A&F University Yangling Shaanxi 712100 China
| | - Yuanmei Xu
- College of Mechanical and Electronic Engineering Northwest A&F University Yangling Shaanxi 712100 China
| | - Gaoji Yang
- College of Mechanical and Electronic Engineering Northwest A&F University Yangling Shaanxi 712100 China
| | - Juanjuan Xu
- College of Mechanical and Electronic Engineering Northwest A&F University Yangling Shaanxi 712100 China
| | - Shuang Zhang
- College of Mechanical and Electronic Engineering Northwest A&F University Yangling Shaanxi 712100 China
- Department of Biological Systems Engineering Washington State University Pullman WA 99164‐6120 USA
| | - Rui Li
- College of Mechanical and Electronic Engineering Northwest A&F University Yangling Shaanxi 712100 China
| | - Shaojin Wang
- College of Mechanical and Electronic Engineering Northwest A&F University Yangling Shaanxi 712100 China
- Department of Biological Systems Engineering Washington State University Pullman WA 99164‐6120 USA
| |
Collapse
|
10
|
Jiao S, Zhang H, Liao M, Hayouka Z, Jing P. Investigation of the potential direct and cross protection effects of sublethal injured Salmonella Typhimurium induced by radio frequency heating stress. Food Res Int 2021; 150:110789. [PMID: 34865804 DOI: 10.1016/j.foodres.2021.110789] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 09/22/2021] [Accepted: 10/24/2021] [Indexed: 10/20/2022]
Abstract
Many studies demonstrated that radio frequency (RF) was an effective pasteurization method for low-moisture foods (LMFs), and our previous study confirmed RF heating stress generated sublethal injured cells (SICs) of Salmonella enterica serovar Typhimurium (S. Typhimurium) in red pepper powder with initial aw ≥ 0.53. So this study investigated the potential direct protection and cross protection effects of the SICs of S. Typhimurium to multiple stresses, and analyzed fatty acid composition and cell morphology. Results showed that the SICs were repaired after incubating for 5 h, and there were no obvious direct and cross protection effects by exposing to different external stresses (heat, 15% ethanol, pH 3.0 acid buffer solution, 10% salt). According to the fatty acid composition analysis, no significant difference (p > 0.05) between the ratio of unsaturated to saturated fatty acids (UFA/SFA) was observed for SICs of S. Typhimurium and control cells, indicating the same membrane fluidity which can support the experimental results. This study investigated and confirmed there are no direct and cross protection effects for the SICs of S. Typhimurium induced by RF heating stress, and it would be helpful for deeply understand the response of pathogens under RF heating stress.
Collapse
Affiliation(s)
- Shunshan Jiao
- SJTU-OSU Innovation Center for Environmental Sustainability and Food Control, Shanghai Food Safety and Engineering Technology Research Center, Key Laboratory of Urban Agriculture, Ministry of Agriculture, School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Rd., Shanghai 200240, China
| | - Hangjin Zhang
- SJTU-OSU Innovation Center for Environmental Sustainability and Food Control, Shanghai Food Safety and Engineering Technology Research Center, Key Laboratory of Urban Agriculture, Ministry of Agriculture, School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Rd., Shanghai 200240, China
| | - Meiji Liao
- SJTU-OSU Innovation Center for Environmental Sustainability and Food Control, Shanghai Food Safety and Engineering Technology Research Center, Key Laboratory of Urban Agriculture, Ministry of Agriculture, School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Rd., Shanghai 200240, China
| | - Zvi Hayouka
- Institute of Biochemistry, Food Science and Nutrition, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel
| | - Pu Jing
- SJTU-OSU Innovation Center for Environmental Sustainability and Food Control, Shanghai Food Safety and Engineering Technology Research Center, Key Laboratory of Urban Agriculture, Ministry of Agriculture, School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Rd., Shanghai 200240, China.
| |
Collapse
|
11
|
|
12
|
Indumathi C, Manoj D, Loganathan M, Shanmugasundaram S. Impact of radiofrequency disinfestation on
Tribolium castaneum
(Herbst) in wheat flour and its influence on the functional characteristics of wheat flour. J FOOD PROCESS PRES 2021. [DOI: 10.1111/jfpp.15770] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- C. Indumathi
- Planning and Monitoring Cell Indian Institute of Food Processing Technology Thanjavur India
| | - D. Manoj
- Planning and Monitoring Cell Indian Institute of Food Processing Technology Thanjavur India
| | - M. Loganathan
- Department of Academics & Human Resource Development Indian Institute of Food Processing Technology Thanjavur India
| | - S. Shanmugasundaram
- Planning and Monitoring Cell Indian Institute of Food Processing Technology Thanjavur India
| |
Collapse
|
13
|
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]
|
14
|
Pasteurization mechanism of S. aureus ATCC 25923 in walnut shells using radio frequency energy at lab level. Lebensm Wiss Technol 2021. [DOI: 10.1016/j.lwt.2021.111129] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
15
|
Affiliation(s)
| | - Senay Simsek
- Department of Plant Sciences North Dakota State University Fargo ND USA
| |
Collapse
|
16
|
|
17
|
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]
|
18
|
Dag D, Singh RK, Kong F. Developments in Radio Frequency Pasteurization of Food Powders. FOOD REVIEWS INTERNATIONAL 2020. [DOI: 10.1080/87559129.2020.1775641] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Damla Dag
- Department of Food Science and Technology, The University of Georgia, Athens, GA, USA
| | - Rakesh K. Singh
- Department of Food Science and Technology, The University of Georgia, Athens, GA, USA
| | - Fanbin Kong
- Department of Food Science and Technology, The University of Georgia, Athens, GA, USA
| |
Collapse
|
19
|
Kim SS, Choi W, Park SH, Kang DH. Mathematical modeling of ohmic heating for inactivation of acid-adapted foodborne pathogens in tomato juice. INTERNATIONAL JOURNAL OF FOOD ENGINEERING 2020. [DOI: 10.1515/ijfe-2019-0388] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
AbstractThe objective of the present study was to predict the inactivation trends of acid-adapted foodborne pathogens in tomato juice by ohmic heating through a numerical analysis method. The mathematical model based on finite element method (FEM) was used to simulate the multiphysics phenomena including electric heating, heat transfer, fluid dynamics, and pathogen inactivation. A cold spot was observed in the corner part of the ohmic heating chamber, where some pathogens survived even though all pathogens were inactivated elsewhere. Challenges of this study were how to reflect the increased resistance of pathogen by acid-adaptation. After simulation, we verified that inactivation level of acid-adapted foodborne pathogens by 25 Vrms/cm ohmic heating (1 kHz), predicted with the developed mathematical model, had no significant differences with experimental results (p > 0.05). Therefore, the mathematical approaches described in the present study will help juice processors determine the processing conditions necessary to ensure microbial safety at the cold point of a rectangular type batch ohmic heater.
Collapse
Affiliation(s)
- Sang-Soon Kim
- Department of Food Engineering, Dankook University, Cheonan, Chungnam, 31116, Republic of Korea
| | - Won Choi
- Department of Landscape Architecture and Rural Systems Engineering, Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Sang-Hyun Park
- Department of Food Science and Technology, Kongju National University, Yesan, Chungnam, 32439, Republic of Korea
| | - Dong-Hyun Kang
- Department of Agricultural Biotechnology, Center for Food and Bioconvergence, and Research Institute for Agricultural and Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea
- Institutes of Green Bio Science & Technology, Seoul National University, Pyeongchang-gun, Gangwon-do, 25354, Republic of Korea
| |
Collapse
|
20
|
Zhang L, Lan R, Zhang B, Erdogdu F, Wang S. A comprehensive review on recent developments of radio frequency treatment for pasteurizing agricultural products. Crit Rev Food Sci Nutr 2020; 61:380-394. [PMID: 32156148 DOI: 10.1080/10408398.2020.1733929] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Recent pathogen incidents have forced food industry to seek for alternative processes in postharvest pasteurization of agricultural commodities. Radio frequency (RF) heating has been used as one alternative treatment to replace chemical fumigation and other conventional thermal methods since it is relatively easy to apply and leaves no chemical residues. RF technology transfers electromagnetic energy into large bulk volume of the products to provide a fast and volumetric heating. There are two types of RF technology commonly applied in lab and industry to generate the heat energy: free running oscillator and 50-Ω systems. Several reviews have been published to introduce the application of RF heating in food processing. However, few reviews have a comprehensive summary of RF treatment for pasteurizing agricultural products. The objective of this review was to introduce the developments in the RF pasteurization of agricultural commodities and to present future directions of the RF heating applications. While the recent developments in the RF pasteurization were presented, thermal death kinetics of targeted pathogens as influenced by water activity, pathogen species and heating rates, non-thermal effects of RF heating, combining RF heating with other technologies for pasteurization, RF heating uniformity improvements using computer simulation and development of practical RF pasteurization processes were also focused. This review is expected to provide a comprehensive understanding of RF pasteurization for agricultural products and promote the industrial-scale applications of RF technology with possible process protocol optimization purposes.
Collapse
Affiliation(s)
- Lihui Zhang
- College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling, China
| | - Ruange Lan
- College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling, China
| | - Beihua Zhang
- College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling, China
| | - Ferruh Erdogdu
- Department of Food Engineering, Ankara University, Golbası-Ankara, Turkey
| | - Shaojin Wang
- College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling, China.,Department of Biological Systems Engineering, Washington State University, Pullman, Washington, USA
| |
Collapse
|
21
|
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.
Collapse
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
| |
Collapse
|
22
|
Dielectric properties, heating rate, and heating uniformity of wheat flour with added bran associated with radio frequency treatments. INNOV FOOD SCI EMERG 2020. [DOI: 10.1016/j.ifset.2020.102290] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
23
|
Xu J, Yang R, Jin Y, Barnett G, Tang J. Modeling the temperature-dependent microbial reduction of Enterococcus faecium NRRL B-2354 in radio-frequency pasteurized wheat flour. Food Control 2020. [DOI: 10.1016/j.foodcont.2019.106778] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
24
|
Zhang H, Zhao Y, Gong C, Jiao S. Effect of radio frequency heating stress on sublethal injury of Salmonella Typhimurium in red pepper powder. Lebensm Wiss Technol 2020. [DOI: 10.1016/j.lwt.2019.108700] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
|
25
|
|
26
|
Peng J, Yin X, Jiao S, Wei K, Tu K, Pan L. Air jet impingement and hot air-assisted radio frequency hybrid drying of apple slices. Lebensm Wiss Technol 2019. [DOI: 10.1016/j.lwt.2019.108517] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
27
|
Ling B, Cheng T, Wang S. Recent developments in applications of radio frequency heating for improving safety and quality of food grains and their products: A review. Crit Rev Food Sci Nutr 2019; 60:2622-2642. [DOI: 10.1080/10408398.2019.1651690] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Bo Ling
- College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling, Shaanxi, China
| | - Teng Cheng
- College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling, Shaanxi, China
| | - Shaojin Wang
- College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling, Shaanxi, China
- Department of Biological Systems Engineering, Washington State University, Pullman, WA, USA
| |
Collapse
|
28
|
Zhou X, Ramaswamy H, Qu Y, Xu R, Wang S. Combined radio frequency-vacuum and hot air drying of kiwifruits: Effect on drying uniformity, energy efficiency and product quality. INNOV FOOD SCI EMERG 2019. [DOI: 10.1016/j.ifset.2019.102182] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
29
|
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]
|
30
|
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]
|
31
|
Radio-frequency treatment for stabilization of wheat germ: Storage stability and physicochemical properties. INNOV FOOD SCI EMERG 2019. [DOI: 10.1016/j.ifset.2018.12.002] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
32
|
Jiang H, Gu Y, Gou M, Xia T, Wang S. Radio frequency pasteurization and disinfestation techniques applied on low-moisture foods. Crit Rev Food Sci Nutr 2019; 60:1417-1430. [DOI: 10.1080/10408398.2019.1573415] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Hao Jiang
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, China
- College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling, Shaanxi, China
| | - Yuxiang Gu
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, China
| | - Min Gou
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, China
| | - Tianyu Xia
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, China
| | - Shaojin Wang
- College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling, Shaanxi, China
- Department of Biological Systems Engineering, Washington State University, Pullman, Washington, USA
| |
Collapse
|