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Pabst CR, Kharel K, De J, Bardsley CA, Bertoldi B, Schneider KR. Evaluating the efficacy of peroxyacetic acid in preventing Salmonella cross-contamination on tomatoes in a model flume system. Heliyon 2024; 10:e31521. [PMID: 38813225 PMCID: PMC11133892 DOI: 10.1016/j.heliyon.2024.e31521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 05/14/2024] [Accepted: 05/17/2024] [Indexed: 05/31/2024] Open
Abstract
The use of flume tanks for tomato processing has been identified as a potential source of cross-contamination, which could result in foodborne illness. This study's objective was to assess the efficacy of peroxyacetic acid (PAA) at a concentration of ≤80 mg/L in preventing Salmonella enterica cross-contamination under various organic loads in a benchtop model tomato flume tank. The stability of 80 mg/L PAA at different chemical oxygen demand (COD) levels was also tested. Tomatoes were spot inoculated with a five-serovar rifampin-resistant (rif+) Salmonella cocktail (106 or 108 colony forming unit (CFU)/tomato). Inoculated (n = 3) and uninoculated (n = 9) tomatoes were introduced into the flume system containing 0-80 mg/L PAA and 0 or 300 mg/L COD. After washing for 30, 60, or 120 s, uninoculated tomatoes were sampled and analyzed for cross-contamination. All experiments were conducted in triplicate. Increasing the organic load (measured as COD) affected the stability of PAA in water with significantly faster dissociation when exposed to 300 mg/L COD. The concentration of PAA, inoculum level, COD levels, and time intervals were all significant factors that affected cross-contamination. Cross-contamination occurred at the high inoculum level (108 CFU/tomato) even when 80 mg/L PAA was present in the model flume tank, regardless of the organic load level. When the tomatoes were contaminated at a level of 106 CFU/tomato, concentrations as low as 5 mg/L of PAA were effective in preventing cross-contamination at 0 mg/L COD; however, 100 % tomatoes (9/9) were positive when the organic load increased to 300 mg/L COD. When the PAA concentration was increased to 10 mg/L, it effectively prevented cross-contamination in the tank, regardless of the presence of organic load. These results suggest that using PAA at concentrations below the maximum limit remains effective in limiting bacterial cross-contamination and offers a more environment-friendly option for tomato packinghouse operators.
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Affiliation(s)
- Christopher R. Pabst
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, FL, 32611, USA
| | - Karuna Kharel
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, FL, 32611, USA
| | - Jaysankar De
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, FL, 32611, USA
- Department of Microbiology & Cell Science, University of Florida, Gainesville, FL, 32611, USA
| | - Cameron A. Bardsley
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, FL, 32611, USA
- USDA-ARS Southeastern Fruit and Tree Nut Research Station, Byron, GA, 31008, USA
| | - Bruna Bertoldi
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, FL, 32611, USA
| | - Keith R. Schneider
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, FL, 32611, USA
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Su Y, Shen X, Liu A, Zhu MJ. Evaluation of Enterococcus faecium NRRL B-2354 as a surrogate for Listeria monocytogenes during chlorine and peroxyacetic acid interventions in simulated apple dump tank water. Int J Food Microbiol 2024; 414:110613. [PMID: 38341905 DOI: 10.1016/j.ijfoodmicro.2024.110613] [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: 08/17/2023] [Revised: 01/23/2024] [Accepted: 01/30/2024] [Indexed: 02/13/2024]
Abstract
Sanitizers are widely incorporated in commercial apple dump tank systems to mitigate the cross-contamination of foodborne pathogens. This study validated the suitability of Enterococcus faecium NRRL B-2354 as a surrogate for Listeria monocytogenes during sanitizer interventions in dump tank water systems. E. faecium NRRL B-2354 inoculated on apples exhibited statistically equivalent susceptibility to L. monocytogenes when exposed to chlorine-based sanitizers (25-100 ppm free chlorine (FC)) and peroxyacetic acid (PAA, 20-80 ppm) in simulated dump tank water (SDTW) with 1000 ppm chemical oxygen demand (COD), resulting in 0.2-0.9 and 1.1-1.7 log CFU/apple reduction, respectively. Increasing the contact time did not affect sanitizer efficacies against E. faecium NRRL B-2354 and L. monocytogenes on apples. Chlorine and PAA interventions demonstrated statistically similar efficacies against both bacteria inoculated in SDTW. Chlorine at 25 and 100 ppm FC for 0.5-5 min contact yielded ~37.68-78.25 % and > 99.85 % inactivation, respectively, in water with 1000-4000 ppm COD, while ~51.55-99.86 % and > 99.97 % inactivation was observed for PAA at 20 and 80 ppm, respectively. No statistically significant difference was observed between the transference of E. faecium NRRL B-2354 and L. monocytogenes from inoculated apples to uninoculated apples and water, and from water to uninoculated apples during chlorine- or PAA-treated SDTW exposure. The data suggest E. faecium NRRL B-2354 is a viable surrogate for L. monocytogenes in dump tank washing systems, which could be used to predict the anti-Listeria efficacy of chlorine and PAA interventions during commercial apple processing. Further investigations are recommended to assess the suitability of E. faecium NRRL B-2354 as a surrogate for L. monocytogenes, when using different sanitizers and different types of produce to ensure reliable and comprehensive results.
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Affiliation(s)
- Yuan Su
- School of Food Science, Washington State University, Pullman, WA 99164, United States of America
| | - Xiaoye Shen
- School of Food Science, Washington State University, Pullman, WA 99164, United States of America
| | - Andrew Liu
- School of Food Science, Washington State University, Pullman, WA 99164, United States of America
| | - Mei-Jun Zhu
- School of Food Science, Washington State University, Pullman, WA 99164, United States of America.
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Koutsoumanis K, Ordóñez AA, Bolton D, Bover‐Cid S, Chemaly M, De Cesare A, Herman L, Hilbert F, Lindqvist R, Nauta M, Nonno R, Peixe L, Ru G, Simmons M, Skandamis P, Suffredini E, Banach J, Ottoson J, Zhou B, da Silva Felício MT, Jacxsens L, Martins JL, Messens W, Allende A. Microbiological hazards associated with the use of water in the post-harvest handling and processing operations of fresh and frozen fruits, vegetables and herbs (ffFVHs). Part 1 (outbreak data analysis, literature review and stakeholder questionnaire). EFSA J 2023; 21:e08332. [PMID: 37928944 PMCID: PMC10623241 DOI: 10.2903/j.efsa.2023.8332] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2023] Open
Abstract
The contamination of water used in post-harvest handling and processing operations of fresh and frozen fruit, vegetables and herbs (ffFVHs) is a global concern. The most relevant microbial hazards associated with this water are: Listeria monocytogenes, Salmonella spp., human pathogenic Escherichia coli and enteric viruses, which have been linked to multiple outbreaks associated with ffFVHs in the European Union (EU). Contamination (i.e. the accumulation of microbiological hazards) of the process water during post-harvest handling and processing operations is affected by several factors including: the type and contamination of the FVHs being processed, duration of the operation and transfer of microorganisms from the product to the water and vice versa, etc. For food business operators (FBOp), it is important to maintain the microbiological quality of the process water to assure the safety of ffFVHs. Good manufacturing practices (GMP) and good hygienic practices (GHP) related to a water management plan and the implementation of a water management system are critical to maintain the microbiological quality of the process water. Identified hygienic practices include technical maintenance of infrastructure, training of staff and cooling of post-harvest process water. Intervention strategies (e.g. use of water disinfection treatments and water replenishment) have been suggested to maintain the microbiological quality of process water. Chlorine-based disinfectants and peroxyacetic acid have been reported as common water disinfection treatments. However, given current practices in the EU, evidence of their efficacy under industrial conditions is only available for chlorine-based disinfectants. The use of water disinfection treatments must be undertaken following an appropriate water management strategy including validation, operational monitoring and verification. During operational monitoring, real-time information on process parameters related to the process and product, as well as the water and water disinfection treatment(s) are necessary. More specific guidance for FBOp on the validation, operational monitoring and verification is needed.
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Su Y, Shen X, Chiu T, Green T, Zhu MJ. Efficacy of chlorine and peroxyacetic acid to control Listeria monocytogenes on apples in simulated dump tank water system. Food Microbiol 2022; 106:104033. [DOI: 10.1016/j.fm.2022.104033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 03/22/2022] [Accepted: 03/22/2022] [Indexed: 11/29/2022]
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Bertoldi B, Bardsley CA, Pabst CR, Baker CA, Gutierrez A, De J, Luo Y, Schneider KR. Influence of Free Chlorine and Contact Time on the Reduction of Salmonella Cross-Contamination of Tomatoes in a Model Flume System. J Food Prot 2022; 85:22-26. [PMID: 34469547 DOI: 10.4315/jfp-21-212] [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: 05/17/2021] [Accepted: 09/01/2021] [Indexed: 11/11/2022]
Abstract
ABSTRACT The process of washing tomatoes in dump (flume) tanks has been identified as a potential source of cross-contamination. This study's objective was to assess the potential for Salmonella enterica cross-contamination at various inoculation levels in the presence of free chlorine (HOCl) and organic matter. Uninoculated tomatoes were introduced into a laboratory-based model flume containing tomatoes inoculated with a cocktail of five rifampin-resistant S. enterica serovars at 104, 106, or 108 CFU per tomato in water containing 0 or 25 mg/L HOCl and 0 or 300 mg/L chemical oxygen demand (COD). Uninoculated tomatoes exposed to the inoculated tomatoes were removed from the water after 5, 30, 60, and 120 s and placed in bags containing tryptic soy broth supplemented with rifampin and 0.1% sodium thiosulfate. Following incubation, enrichment cultures were plated on tryptic soy agar supplemented with rifampin and xylose lysine deoxycholate agar to determine the presence of Salmonella. HOCl and pH were measured before and after each trial. The HOCl in water containing 300 mg/L COD significantly declined (P ≤ 0.05) by the end of each 120-s trial, most likely due to the increased demand for the oxidant. Higher inoculum levels and lower HOCl concentrations were significant factors (P ≤ 0.05) that contributed to increased cross-contamination. At 25 mg/L HOCl, no Salmonella was recovered under all conditions from uninoculated tomatoes exposed to tomatoes inoculated at 104 CFU per tomato. When the inoculum was increased to 106 and 108 CFU per tomato, cross-contamination was observed, independent of COD levels. The results from this study indicate that the currently required sanitizer concentration (e.g., 100 or 150 mg/L) for flume water may be higher than necessary and warrants reevaluation. HIGHLIGHTS
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Affiliation(s)
- Bruna Bertoldi
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, Florida 32611
| | - Cameron A Bardsley
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, Florida 32611
| | - Christopher R Pabst
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, Florida 32611
| | - Christopher A Baker
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, Florida 32611
| | - Alan Gutierrez
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, Florida 32611
| | - Jaysankar De
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, Florida 32611
| | - Yaguang Luo
- U.S. Department of Agriculture, Agricultural Research Service, Environmental Microbial and Food Safety Laboratory, Beltsville, Maryland 20705, USA
| | - Keith R Schneider
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, Florida 32611
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Bertoldi B, Bardsley CA, Baker CA, Pabst CR, Gutierrez A, De J, Luo Y, Schneider KR. Determining Bacterial Load and Water Quality Parameters of Chlorinated Tomato Flume Tanks in Florida Packinghouses. J Food Prot 2021; 84:1784-1792. [PMID: 34086886 DOI: 10.4315/jfp-21-100] [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: 03/08/2021] [Accepted: 06/01/2021] [Indexed: 11/11/2022]
Abstract
ABSTRACT Monitoring and maintenance of water quality in dump tanks or flume systems is crucial to maintaining proper sanitizer levels to prevent pathogen cross-contamination during postharvest washing of tomatoes, but there is limited information on how organic matter influences sanitizer efficacy in the water. The main objective of this study was to monitor water quality in flume tanks and evaluate the efficacy of postharvest washing of tomatoes in commercial packinghouses. Flume tank water samples (n = 3) were collected on an hourly basis from three packinghouses in Florida and analyzed for pH, total dissolved solids (TDS), free chlorine, chemical oxygen demand (COD), oxidation-reduction potential, and turbidity. Additionally, three flume-water samples were collected and tested for total aerobic plate count (APC), total coliforms (TC), and Escherichia coli. Fresh tomatoes (n = 3), both before and after washing, were collected and analyzed for the same bacterial counts. Turbidity, COD, and TDS levels in flume water increased over time in all packinghouses. Correlations observed include COD and turbidity (r = 0.631), turbidity and TDS (r = 0.810), and oxidation-reduction potential and chlorine (r = 0.660). APC for water samples had an average range of 0.0 to 4.7 log CFU/mL and TC average range of 0.0 to 4.7 log CFU/mL. All water samples were negative for E. coli. The average APC for pre- and postflume tomatoes from the three packinghouses was 6.0 log CFU per tomato and ranged from 2.2 to 7.4 log CFU per tomato. The average TC count was <1.5 and 7.0 log CFU per tomato for pre- and postwash tomatoes, respectively. There was no significant effect (P > 0.05) of postharvest washing on the microbiological qualities of tomatoes. Water quality in flume tanks deteriorated over time in all packinghouses during a typical operational day of 4 to 8 h. HIGHLIGHTS
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Affiliation(s)
- Bruna Bertoldi
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, Florida 32611
| | - Cameron A Bardsley
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, Florida 32611
| | - Christopher A Baker
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, Florida 32611
| | - Christopher R Pabst
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, Florida 32611
| | - Alan Gutierrez
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, Florida 32611
| | - Jaysankar De
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, Florida 32611
| | - Yaguang Luo
- Environmental Microbial and Food Safety Laboratories, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, Maryland 20705, USA
| | - Keith R Schneider
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, Florida 32611
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Zhou B, Luo Y, Teng ZI, Nou X, Millner P. Factors Impacting Chemical and Microbiological Quality of Wash Water during Simulated Dump Tank Wash of Grape Tomatoes. J Food Prot 2021; 84:695-703. [PMID: 33270875 DOI: 10.4315/jfp-20-343] [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: 08/25/2020] [Accepted: 12/01/2020] [Indexed: 11/11/2022]
Abstract
ABSTRACT Fresh and fresh-cut tomatoes are high in phytonutrients. However, illness outbreaks associated with contaminated tomatoes have significantly impacted public health and the economic well-being of the tomato industry. Scientific information is needed to develop an effective, practical food safety standard to reduce pathogen contamination. The aim of this study was to assess factors impacting the deterioration of the quality of tomato wash water and the proliferation of indigenous microorganisms during a simulated dump tank washing process. Freshly harvested grape tomatoes were sorted into four groups: prime, defective, underripe, and nontomato debris. Tomatoes with leaf or stem harvest debris, combined or separate, were washed in tap water with or without free chlorine. Water samples were analyzed for total dissolved solids, turbidity, chemical oxygen demand, and chlorine demand. Microbial populations in water and on tomatoes as impacted by chlorine concentration and water filtration (300 μm) were also quantified. Field debris and defective tomatoes were the major contributors to microbial populations in wash water. Field debris, although accounting for <1% of the total weight of harvested material, contributed 37.84% of total dissolved solids, 46.15% of turbidity, 48.77% of chemical oxygen demand, and 50.55% of chlorine demand in the wash water. Water quality deterioration was proportional to the cumulative quantity of tomatoes and debris washed, and free chlorine at ≥5 mg/L significantly reduced the Enterobacteriaceae, aerobic mesophilic bacteria, and yeast and mold populations. These results highlight the importance of minimizing field debris and defective fruits in harvested grape tomatoes to reduce the microbial load and prevent deterioration of wash water quality. This information will be useful for the development of data-driven harvesting and packinghouse food safety practices for grape tomatoes. HIGHLIGHTS
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Affiliation(s)
- Bin Zhou
- U.S. Department of Agriculture, Agricultural Research Service, Food Quality Laboratory, Beltsville, Maryland 20705.,U.S. Department of Agriculture, Agricultural Research Service, Environmental Microbial and Food Safety Laboratory, 10300 Baltimore Avenue, Beltsville, Maryland 20705, USA (ORCID: https://orcid.org/0000-0001-6164-4318 [Y.L.]; https://orcid.org/0000-0001-6877-7527 [P.M.])
| | - Yaguang Luo
- U.S. Department of Agriculture, Agricultural Research Service, Food Quality Laboratory, Beltsville, Maryland 20705.,U.S. Department of Agriculture, Agricultural Research Service, Environmental Microbial and Food Safety Laboratory, 10300 Baltimore Avenue, Beltsville, Maryland 20705, USA (ORCID: https://orcid.org/0000-0001-6164-4318 [Y.L.]; https://orcid.org/0000-0001-6877-7527 [P.M.])
| | - Z I Teng
- U.S. Department of Agriculture, Agricultural Research Service, Food Quality Laboratory, Beltsville, Maryland 20705
| | - Xiangwu Nou
- U.S. Department of Agriculture, Agricultural Research Service, Food Quality Laboratory, Beltsville, Maryland 20705
| | - Patricia Millner
- U.S. Department of Agriculture, Agricultural Research Service, Environmental Microbial and Food Safety Laboratory, 10300 Baltimore Avenue, Beltsville, Maryland 20705, USA (ORCID: https://orcid.org/0000-0001-6164-4318 [Y.L.]; https://orcid.org/0000-0001-6877-7527 [P.M.])
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Wang P, Pitts KB, Chen J. Efficacy of commercial overhead washing and waxing systems on the microbiological quality of fresh peaches. Food Microbiol 2021; 97:103761. [PMID: 33653531 DOI: 10.1016/j.fm.2021.103761] [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: 09/01/2020] [Revised: 02/02/2021] [Accepted: 02/03/2021] [Indexed: 11/26/2022]
Abstract
Overhead spray washing and waxing systems (WWS) are used commercially to reduce the risk of microbial contamination and improve the quality of fresh produce during packing. This study evaluated the microbiological quality of overhead spray water and spent peach wash water, as well as fresh peaches before and after they pass the WWS. Pre- and post-washed/waxed peach samples (n = 192) and overhead spray water and spent peach wash water samples (n = 54) were collected several times over the course of a processing day in three packing facilities located in the state of Georgia. Populations of total aerobes (TA), yeasts and molds (YM), and coliforms (TC) and the presence of thermotolerant coliforms (TTC) and enterococci (EC) were measured in collected samples. The average TA and TC counts and the incidences of TTC and EC were significantly higher (P < 0.05) on peach samples collected after the WWS compared to those collected before the WWS. Counts and incidences of TA, YM, and TC in spent peach wash water were significantly higher than in the overhead spray water where neither TTC nor EC was detected. Results suggest that the commercial washing and waxing systems had little effect in improving the microbiological quality of fresh peaches.
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Affiliation(s)
- Peien Wang
- Department of Food Science and Technology, The University of Georgia, Griffin, GA, 30223-1797, USA
| | - Katie B Pitts
- Georgia Peach Council, P.O. Box 2133, Fort Valley, GA, 31030, USA
| | - Jinru Chen
- Department of Food Science and Technology, The University of Georgia, Griffin, GA, 30223-1797, USA.
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Loayza FE, Brecht JK, Simonne AH, Plotto A, Baldwin EA, Bai J, Lon-Kan E. A brief hot-water treatment alleviates chilling injury symptoms in fresh tomatoes. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2021; 101:54-64. [PMID: 32949019 DOI: 10.1002/jsfa.10821] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 09/09/2020] [Accepted: 09/18/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Reducing the negative effects of chilling injury (CI) in tomatoes after harvest is essential to ensure good quality and to minimize losses. CI is a postharvest disorder associated with the generation of reactive oxygen species (ROS) in the fruit. Therefore, antioxidant accumulation can counteract ROS, alleviating CI symptoms. In this sense, it has been confirmed that a brief hot-water (HW) immersion promotes the synthesis of antioxidants. RESULTS HW treatment at 52 °C for 5 min significantly reduced chilling-associated decay, from 66.7% to 17.2% in breaker turning (BT) and from 55.8% to 9.8% in mature green (MG) 'BHN-602' tomatoes stored at 5 °C for 2 weeks and from 26.7% to 6.7% in BT tomatoes stored at 5 °C for 1 week. Also, HW treatment significantly increased lycopene content by 17% in BT tomatoes stored at 5 °C for 2 weeks, as well as ascorbic acid by 11%, lipophilic phenolics by 18% and total phenolics by 6.5% in BT tomatoes stored at 12.5 °C for 1 week. Despite the increase of antioxidants, HW treatment did not enhance the sensory aromatic profile, color and antioxidant capacity. Interestingly, HW treatment reduced ripening time by 3 days in MG tomatoes stored at 5 °C for 2 weeks or at 12.5 °C for 1 week. CONCLUSION HW treatment applied to MG or BT 'BHN-602' tomatoes can alleviate the development of some CI symptoms, particularly decay, possibly by increasing antioxidants that scavenge ROS. © 2020 Society of Chemical Industry.
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Affiliation(s)
- Francisco E Loayza
- Horticultural Sciences Department, University of Florida, Gainesville, FL, USA
| | - Jeffrey K Brecht
- Horticultural Sciences Department, University of Florida, Gainesville, FL, USA
| | - Amarat H Simonne
- Family, Youth and Community Sciences Department, University of Florida, Gainesville, FL, USA
| | - Anne Plotto
- US Horticultural Research Laboratory, USDA ARS, Fort Pierce, FL, USA
| | | | - Jinhe Bai
- US Horticultural Research Laboratory, USDA ARS, Fort Pierce, FL, USA
| | - Elena Lon-Kan
- Horticultural Sciences Department, University of Florida, Gainesville, FL, USA
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Sheng L, Shen X, Su Y, Korany A, Knueven CJ, Zhu MJ. The efficacy of sodium acid sulfate on controlling Listeria monocytogenes on apples in a water system with organic matter. Food Microbiol 2020; 92:103595. [PMID: 32950137 DOI: 10.1016/j.fm.2020.103595] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 06/26/2020] [Accepted: 06/28/2020] [Indexed: 11/29/2022]
Abstract
During fresh apple packing, wash water in the dump tank and flume systems is reused during daily production, resulting in high levels of organic matter in the wash water. This study evaluated the antimicrobial efficacy of sodium acid sulfate (SAS), a Generally Recognized as Safe compound, against Listeria monocytogenes on fresh apples in a water system with high organic load. SAS at 1.0% reduced L. monocytogenes population in water with 1000 ppm chemical oxygen demand (COD) by more than 5.0 Log10 CFU/ml in 5 min, 2.0-3.0% SAS reduced L. monocytogenes to undetectable levels (10 CFU/ml) within 2 min regardless of organic levels. When applied on apples, a 2-min wash with SAS at 1.0, 1.5, 2.0, and 3.0% reduced L. monocytogenes by ~1.3, 1.9, 2.3, and 3.0 Log10 CFU/apple in clean water, respectively. High organic load in wash water up to 4000 ppm COD had no impact on the bactericidal effect of SAS against L. monocytogenes on fresh apples regardless of SAS concentrations. Shortening the contact time from 2 min to 30 s significantly reduced the antimicrobial efficacy of 25 ppm chlorine and 1.0-2.0% SAS but not that of 3.0% SAS. In addition, SAS at 1.0% demonstrated a better efficacy than 25 ppm chlorine in reducing fruit-to-water cross-contamination regardless of organic matter. SAS also showed a comparable efficacy as 25 ppm chlorine in reducing fruit-to-fruit cross-contamination in water with organic matter. The collective data indicate that SAS, as an enviroment-friendly compound, has the potential to be used as an alternative antimicrobial washing aid in dump tank process water intervention in apple packing facilities.
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Affiliation(s)
- Lina Sheng
- School of Food Science, Washington State University, Pullman, WA 99164, USA
| | - Xiaoye Shen
- School of Food Science, Washington State University, Pullman, WA 99164, USA
| | - Yuan Su
- School of Food Science, Washington State University, Pullman, WA 99164, USA
| | - Ahmed Korany
- School of Food Science, Washington State University, Pullman, WA 99164, USA
| | | | - Mei-Jun Zhu
- School of Food Science, Washington State University, Pullman, WA 99164, USA.
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Survival of Salmonella enterica and shifts in the culturable mesophilic aerobic bacterial community as impacted by tomato wash water particulate size and chlorine treatment. Food Microbiol 2020; 90:103470. [DOI: 10.1016/j.fm.2020.103470] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 02/18/2020] [Accepted: 02/19/2020] [Indexed: 11/21/2022]
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Application of an innovative water-assisted ultraviolet C light technology for the inactivation of microorganisms in tomato processing industries. Food Microbiol 2020; 94:103631. [PMID: 33279063 DOI: 10.1016/j.fm.2020.103631] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 08/24/2020] [Accepted: 08/25/2020] [Indexed: 11/21/2022]
Abstract
We aimed to study the efficacy of a water-assisted UVC light device (WUVC) as an innovative clean technology for the disinfection of fresh sound tomatoes and processing wash water and water turbidity was evaluated as a critical parameter. First, wash waters with different turbidities (from 0.4 to 828 NTU) were inoculated with Listeria innocua and treated in the WUVC device at different dosages. Secondly, fresh tomatoes, inoculated with L. innocua and non-inoculated ones, were treated using the WUVC device containing wash water of different turbidities for different times. The reduction of L. innocua populations on wash water and on the surface of tomato was influenced by turbidity; lower reduction values were observed at higher turbidities. Washing tomatoes with tap water with UVC lamps off (control treatment, TW) decreased L. innocua population on the surface of tomatoes but did not eliminate those bacteria that went into the water. Contrarily, when UVC lights were on, L. innocua population in wash water after treatment significantly decreased, those in clean water being the lowest populations. Reductions of native microbiota on the clean water treated with the highest UV-C radiation dose were lower than those obtained when tomatoes were artificially inoculated. We demonstrated that high reductions of L. innocua population on fresh tomatoes could be achieved using the WUVC system but some drawbacks related to the increase of turbidity should be solved for its implementation in real conditions.
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Salmonella inactivation and cross-contamination on cherry and grape tomatoes under simulated wash conditions. Food Microbiol 2020; 87:103359. [DOI: 10.1016/j.fm.2019.103359] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 08/31/2019] [Accepted: 11/01/2019] [Indexed: 11/24/2022]
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Ghostlaw T, Corradini MG, Autio WR, Kinchla AJ. Impact of various postharvest wash water conditions on the performance of peracetic acid against Escherichia coli O157:H7 over time. Food Control 2020. [DOI: 10.1016/j.foodcont.2019.106891] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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15
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Li J, Teng Z, Weng S, Zhou B, Turner ER, Vinyard BT, Luo Y. Dynamic changes in the physicochemical properties of fresh-cut produce wash water as impacted by commodity type and processing conditions. PLoS One 2019; 14:e0222174. [PMID: 31557181 PMCID: PMC6762053 DOI: 10.1371/journal.pone.0222174] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 08/22/2019] [Indexed: 01/26/2023] Open
Abstract
Organic materials in fresh-cut produce wash water deplete free chlorine that is required to prevent pathogen survival and cross-contamination. This research evaluated water quality parameters frequently used to describe organic load for their fitness to predict chlorine demand (CLD) and chemical oxygen demand (COD), which are major needs identified by the industry-led produce food safety taskforce. Batches of romaine lettuce, iceberg lettuce, or carrot of different cut sizes and shapes were washed in 40 liters of water. Physicochemical properties of wash water including CLD, COD, total organic carbon (TOC), total suspended solids (TSS), total dissolved solids (TDS), turbidity, total sugar content, and pH, were monitored. Results indicate that pH is primarily commodity dependent, while organic load is additionally impacted by cutting and washing conditions. Significant linear increases in COD, TOC, CLD, TDS, and turbidity resulted from increasing product-to-water ratio, and decreasing cut size. Physicochemical parameters, excluding pH, showed significant positive correlation across different cut sizes within a commodity. High correlations were obtained between CLD and COD and between COD and TOC for pooled products. The convenient measurement of TDS, along with its strong correlation with COD and CLD, suggests the potential of TDS for predicting organic load and chlorine reactivity. Finally, the potential application and limitation of the proposed models in practical produce processing procedures are discussed extensively.
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Affiliation(s)
- Jie Li
- College of Food Science and Technology, Huazhong Agricultural University, Wuhan, PR China
- U. S. Department of Agriculture, Agricultural Research Service, Beltsville Agricultural, Research Center, Environmental Microbiology and Food Safety Laboratory, Beltsville, MD, United States of America
| | - Zi Teng
- U. S. Department of Agriculture, Agricultural Research Service, Beltsville Agricultural, Research Center, Environmental Microbiology and Food Safety Laboratory, Beltsville, MD, United States of America
- Department of Nutrition and Food Science, University of Maryland, College Park, MD, United States of America
| | - ShihChi Weng
- JHU/MWH Alliance, 615 N. Wolfe St., Johns Hopkins University, Baltimore, MD
| | - Bin Zhou
- U. S. Department of Agriculture, Agricultural Research Service, Beltsville Agricultural, Research Center, Environmental Microbiology and Food Safety Laboratory, Beltsville, MD, United States of America
| | - Ellen R. Turner
- U. S. Department of Agriculture, Agricultural Research Service, Beltsville Agricultural, Research Center, Environmental Microbiology and Food Safety Laboratory, Beltsville, MD, United States of America
| | - Bryan T. Vinyard
- Statistics Group, Northeast Area Office, Agricultural Research Service, United States Department of Agriculture, Beltsville, MD, United States of America
| | - Yaguang Luo
- U. S. Department of Agriculture, Agricultural Research Service, Beltsville Agricultural, Research Center, Environmental Microbiology and Food Safety Laboratory, Beltsville, MD, United States of America
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16
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Impacts and interactions of organic compounds with chlorine sanitizer in recirculated and reused produce processing water. PLoS One 2018; 13:e0208945. [PMID: 30540850 PMCID: PMC6291160 DOI: 10.1371/journal.pone.0208945] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 11/27/2018] [Indexed: 11/19/2022] Open
Abstract
Water conservation and economics dictate that fresh produce processors reuse/recirculate the process water. However, the ensuing accumulation of organic matter in water depletes the chlorine sanitizer required for food safety. In this study, we comprehensively investigated chemical compounds that are responsible for water quality in relation to chemical oxygen demand (COD) and chlorine demand (CLD), the two most critical factors associated with water treatment and chlorine replenishment. Simulating commercial fresh-cut wash operations, multiple batches of diced cabbage (0.3 x 0.3 cm2) were washed in the same tank of water. The major components were isolated from the wash water and analyzed by HPLC. Sugars were the predominant compounds (82.7% dry weight) and the major contributor to COD (81.6%), followed by proteins/peptides (7.3% dry weight, 5.3% COD), organic acids (6.2% dry weight, 3.6% COD), and phenolics (0.5% dry weight, 0.5% COD). By repeated time course measures, the effect of these chemicals on CLD are dependent on the chemical structure, concentration in the wash water, and their rate of reaction. Proteins/peptides accounted for about 50% of the total CLD over a 120-min period and phenolics was 21% at 5 min, but diminished with time. The contribution by organic acids and sugars increased continuously, reaching 22% and 16% of total CLD at 120 min of chlorination, respectively. Collectively, these compounds represented 86% of the CLD in cabbage wash water at 5 min and greater than 94% CLD afterwards. This is the first systematic report on the source of COD and CLD during fresh produce washing. It provides essential information for the produce processors to develop safe, effective, and economical wash water treatment/reuse and chlorine replenishment strategies.
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17
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Zoellner C, Al-Mamun MA, Grohn Y, Jackson P, Worobo R. Postharvest Supply Chain with Microbial Travelers: a Farm-to-Retail Microbial Simulation and Visualization Framework. Appl Environ Microbiol 2018; 84:e00813-18. [PMID: 29959243 PMCID: PMC6102990 DOI: 10.1128/aem.00813-18] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 06/18/2018] [Indexed: 11/20/2022] Open
Abstract
Fresh produce supply chains present variable and diverse conditions that are relevant to food quality and safety because they may favor microbial growth and survival following contamination. This study presents the development of a simulation and visualization framework to model microbial dynamics on fresh produce moving through postharvest supply chain processes. The postharvest supply chain with microbial travelers (PSCMT) tool provides a modular process modeling approach and graphical user interface to visualize microbial populations and evaluate practices specific to any fresh produce supply chain. The resulting modeling tool was validated with empirical data from an observed tomato supply chain from Mexico to the United States, including the packinghouse, distribution center, and supermarket locations, as an illustrative case study. Due to data limitations, a model-fitting exercise was conducted to demonstrate the calibration of model parameter ranges for microbial indicator populations, i.e., mesophilic aerobic microorganisms (quantified by aerobic plate count and here termed APC) and total coliforms (TC). Exploration and analysis of the parameter space refined appropriate parameter ranges and revealed influential parameters for supermarket indicator microorganism levels on tomatoes. Partial rank correlation coefficient analysis determined that APC levels in supermarkets were most influenced by removal due to spray water washing and microbial growth on the tomato surface at postharvest locations, while TC levels were most influenced by growth on the tomato surface at postharvest locations. Overall, this detailed mechanistic dynamic model of microbial behavior is a unique modeling tool that complements empirical data and visualizes how postharvest supply chain practices influence the fate of microbial contamination on fresh produce.IMPORTANCE Preventing the contamination of fresh produce with foodborne pathogens present in the environment during production and postharvest handling is an important food safety goal. Since studying foodborne pathogens in the environment is a complex and costly endeavor, computer simulation models can help to understand and visualize microorganism behavior resulting from supply chain activities. The postharvest supply chain with microbial travelers (PSCMT) model, presented here, provides a unique tool for postharvest supply chain simulations to evaluate microbial contamination. The tool was validated through modeling an observed tomato supply chain. Visualization of dynamic contamination levels from harvest to the supermarket and analysis of the model parameters highlighted critical points where intervention may prevent microbial levels sufficient to cause foodborne illness. The PSCMT model framework and simulation results support ongoing postharvest research and interventions to improve understanding and control of fresh produce contamination.
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Affiliation(s)
- Claire Zoellner
- Department of Food Science, Cornell University, Ithaca, New York, USA
| | - Mohammad Abdullah Al-Mamun
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Yrjo Grohn
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Peter Jackson
- Department of Operations Research and Information Engineering, Cornell University, Ithaca, New York, USA
| | - Randy Worobo
- Department of Food Science, Cornell University, Ithaca, New York, USA
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18
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Abstract
ABSTRACT
Advancements in agriculture and food processing techniques have been instrumental in the development of modern human societies. Vast improvements in agronomic practices, handling, and processing have allowed us to produce and preserve mass quantities of food. Yet despite all these innovations and potentially as a consequence of these mass production practices, more and more outbreaks of human pathogens linked to raw and processed foods are identified every year. It is evident that our increased capacity for microbial detection has contributed to the greater number of outbreaks detected. However, our understanding of how these events originate and what agronomic, packaging, and environmental factors influence the survival, persistence, and proliferation of human pathogens remains of scientific debate. This review seeks to identify those past and current challenges to the safety of fresh produce and focuses on production practices and how those impact produce safety. It reflects on 20 years of research, industry guidelines, and federal standards and how they have evolved to our current understanding of fresh produce safety. This document is not intended to summarize and describe all fruit and vegetable farming practices across the United States and the rest of the world. We understand the significant differences in production practices that exist across regions. This review highlights those general farming practices that significantly impact past and current food safety issues. It focuses on current and future research needs and on preharvest food safety control measures in fresh-produce safety that could provide insight into the mechanisms of pathogen contamination, survival, and inactivation under field and packinghouse conditions.
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19
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A three-year survey of Florida packinghouses to determine microbial loads on pre- and post-processed tomatoes. Food Control 2018. [DOI: 10.1016/j.foodcont.2017.11.036] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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20
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Dynamic changes in free-chlorine levels within a commercial post-harvest wash and prevention of cross-contamination between shredded lettuce batches. Food Control 2018. [DOI: 10.1016/j.foodcont.2017.09.029] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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21
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Zhou B, Luo Y, Bauchan GR, Feng H, Stommel JR. Visualizing pathogen internalization pathways in fresh tomatoes using MicroCT and confocal laser scanning microscopy. Food Control 2018. [DOI: 10.1016/j.foodcont.2017.09.027] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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22
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Teng Z, Luo Y, Alborzi S, Zhou B, Chen L, Zhang J, Zhang B, Millner P, Wang Q. Investigation on chlorine-based sanitization under stabilized conditions in the presence of organic load. Int J Food Microbiol 2018; 266:150-157. [PMID: 29216555 DOI: 10.1016/j.ijfoodmicro.2017.11.027] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 11/28/2017] [Accepted: 11/30/2017] [Indexed: 10/18/2022]
Abstract
Chlorine, the most commonly used sanitizer for fresh produce washing, has constantly shown inferior sanitizing efficacy in the presence of organic load. Conventionally this is attributed indirectly to the rapid chlorine depletion by organics leading to fluctuating free chlorine (FC) contents. However, little is known on whether organic load affects the sanitization process directly at well-maintained FC levels. Hereby, a sustained chlorine decay approach was employed to study the inactivation of Escherichia coli O157:H7 under stabilized washing conditions. Chlorine solution was first incubated with organic load for up to 4h, modeling the chlorination in produce washing lines. The FC level was then stabilized at five targeted values for sanitization study. Our study showed decreased sanitizing efficacy as the organic load increased. At 5s residence time and pH6.5, a minimum of 0.5 and 7.5mg/L FC were needed to achieve a 5 log reduction at 0 and 900mg/L chemical oxygen demand (COD), respectively. The decrease was more pronounced at lower FC, higher COD, higher pH, and shorter residence time values. The organics-associated interference with FC measurement and disruption of chlorine/bacteria interaction, together with the chlorine demand of concentrated inoculum per se, collectively resulted in inadequate sanitization. Finally, our results were compared with existing studies conducted under dynamic conditions in the context of different experimental settings. This study provided a feasible method for studying the bacteria/sanitizer interaction while ruling out the confounding effect from fluctuating FC levels, and it indicated the direct, negative impact of organic load.
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Affiliation(s)
- Zi Teng
- Department of Nutrition and Food Science, University of Maryland, 0112 Skinner Building, College Park, MD 20742, United States
| | - Yaguang Luo
- The Environmental Microbial and Food Safety Lab, Agricultural Research Service, The United States Department of Agriculture, Beltsville, MD 20705, United States
| | - Solmaz Alborzi
- Department of Nutrition and Food Science, University of Maryland, 0112 Skinner Building, College Park, MD 20742, United States
| | - Bin Zhou
- The Environmental Microbial and Food Safety Lab, Agricultural Research Service, The United States Department of Agriculture, Beltsville, MD 20705, United States
| | - Lin Chen
- Department of Nutrition and Food Science, University of Maryland, 0112 Skinner Building, College Park, MD 20742, United States
| | - Jinglin Zhang
- Department of Nutrition and Food Science, University of Maryland, 0112 Skinner Building, College Park, MD 20742, United States
| | - Boce Zhang
- The Environmental Microbial and Food Safety Lab, Agricultural Research Service, The United States Department of Agriculture, Beltsville, MD 20705, United States
| | - Patricia Millner
- The Environmental Microbial and Food Safety Lab, Agricultural Research Service, The United States Department of Agriculture, Beltsville, MD 20705, United States
| | - Qin Wang
- Department of Nutrition and Food Science, University of Maryland, 0112 Skinner Building, College Park, MD 20742, United States.
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23
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Murray K, Wu F, Shi J, Jun Xue S, Warriner K. Challenges in the microbiological food safety of fresh produce: Limitations of post-harvest washing and the need for alternative interventions. FOOD QUALITY AND SAFETY 2017. [DOI: 10.1093/fqsafe/fyx027] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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24
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Schneider K, De J, Li Y, Sreedharan A, Goodrich Schneider R, Danyluk M, Pahl D, Walsh C, Todd-Searle J, Schaffner D, Kline W, Buchanan R. Microbial evaluation of pre- and post-processed tomatoes from Florida, New Jersey and Maryland packinghouses. Food Control 2017. [DOI: 10.1016/j.foodcont.2016.08.048] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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25
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Zhang Z, Guo H, Carlisle T, Mukherjee A, Kinchla A, White JC, Xing B, He L. Evaluation of Postharvest Washing on Removal of Silver Nanoparticles (AgNPs) from Spinach Leaves. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2016; 64:6916-6922. [PMID: 27548506 DOI: 10.1021/acs.jafc.6b02705] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
There is increasing use of silver nanoparticles (AgNPs) as pesticides for fruits and vegetables due to the particles' unique antimicrobial and insecticidal properties. However, residual AgNPs in harvested produce may transfer through the food chain and pose a potential risk to public health. The objective of this study is to determine whether postharvest washing can effectively remove AgNPs that had accumulated on fresh produce. Ten microliters of commercially available 40 nm citrate coated AgNPs (0.4 mg/L) was dropped to a (1 × 1 cm(2)) spot on spinach leaves, followed by washing with deionized water (DI water), Tsunami 100 (80 mg/L), or Clorox bleach (200 mg/L). Then, the AgNP removal efficiency of the three treatments was evaluated by surface-enhanced Raman spectroscopy (SERS), scanning electron microscopy (SEM)-energy dispersive spectrometry (EDS), and inductively coupled plasma mass spectrometry (ICP-MS). ICP-MS results showed that deionized water removed statistically insignificant amounts of total Ag (5%), whereas Tsunami 100 and Clorox bleach yielded 21 and 10% decreases in total Ag, respectively (P < 0.05). The increased removal efficiency resulted from AgNP dissolution and Ag(+) release upon contact with the oxidizing agents in Tsunami 100 (peroxyacetic acid, hydrogen peroxide) and Clorox bleach (sodium hypochlorite). According to the SERS results, the deionized water and Tsunami 100 treatments removed nonsignificant amounts of AgNPs. Clorox bleach decreased Ag NPs by >90% (P < 0.05); however, SEM-EDS images revealed the formation of large silver chloride (AgCl) crystals (162 ± 51 nm) on the leaf, which explained the low total Ag removal from ICP-MS. This study indicates current factory washing methods for fresh produce may not be effective in reducing AgNPs (by water and Tsunami 100) and total Ag (by all three means). This highlights the necessity to develop an efficient washing method for NP removal from food surfaces in the future.
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Affiliation(s)
- Zhiyun Zhang
- Department of Food Science, University of Massachusetts , Amherst, Massachusetts 01003, United States
| | - Huiyuan Guo
- Stockbridge School of Agriculture, University of Massachusetts , Amherst, Massachusetts 01003, United States
| | - Thomas Carlisle
- Department of Food Science, University of Massachusetts , Amherst, Massachusetts 01003, United States
| | - Arnab Mukherjee
- Department of Analytical Chemistry, The Connecticut Agricultural Experiment Station , New Haven, Connecticut 06511, United States
| | - Amanda Kinchla
- Department of Food Science, University of Massachusetts , Amherst, Massachusetts 01003, United States
| | - Jason C White
- Department of Analytical Chemistry, The Connecticut Agricultural Experiment Station , New Haven, Connecticut 06511, United States
| | - Baoshan Xing
- Stockbridge School of Agriculture, University of Massachusetts , Amherst, Massachusetts 01003, United States
| | - Lili He
- Department of Food Science, University of Massachusetts , Amherst, Massachusetts 01003, United States
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26
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Shen C, Norris P, Williams O, Hagan S, Li K. Generation of chlorine by-products in simulated wash water. Food Chem 2016. [DOI: 10.1016/j.foodchem.2015.04.146] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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27
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Gereffi S, Sreedharan A, Schneider KR. Control of Salmonella Cross-Contamination between Green Round Tomatoes in a Model Flume System. J Food Prot 2015; 78:1280-7. [PMID: 26197278 DOI: 10.4315/0362-028x.jfp-14-524] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Tomato Best Management Practices require Florida packers to treat tomatoes in a flume system containing at least 150 ppm of free chlorine or other approved sanitizer. However, research is needed to determine the ability of these sanitizers to prevent the transfer of pathogens from contaminated to uncontaminated tomatoes, particularly under realistic packinghouse conditions. The goal of this research was to assess the minimum levels of sanitizer needed to prevent Salmonella cross-contamination between tomatoes in a model flume system under clean conditions and conditions where organic matter was added. Inoculated tomatoes (ca. 8.3 log CFU per tomato) were treated along with uninoculated tomatoes in a model flume system containing 0, 10, or 25 ppm of hypochlorous acid (HOCl) under organic loading conditions of 0, 500, or 4,000 ppm of chemical oxygen demand (COD). In the absence of HOCl, uninoculated tomatoes were highly contaminated (ca. 5 log CFU per tomato) by 15 s. No contamination was detectable (<2 log CFU per tomato) on uninoculated tomatoes when HOCl was present, except with 10 ppm at 4,000 ppm of COD, suggesting failure of 10 ppm of HOCl as a sanitizer under very high organic loading conditions. In the presence of HOCl or peroxyacetic acid, Salmonella was undetectable (<1 log CFU/ml) in the model flume water samples after 2 and 30 s, respectively. Upon enrichment, none of the uninoculated tomatoes treated with 25 ppm of HOCl for 120 s were positive for Salmonella, even in the presence of organic loading at 500 ppm of COD. Based on these findings, 25 ppm of HOCl may be adequate to prevent cross-contamination when the concentration is properly maintained, COD does not exceed 500 ppm, and tomatoes are treated for at least 120 s. Further validation in a larger commercial setting and using higher organic loading levels is necessary because managing HOCl at this low concentration is difficult, especially in a recirculating system. The use of less sanitizer by packers could reduce chemical and disposal costs.
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Affiliation(s)
- Scott Gereffi
- Department of Food Science and Human Nutrition, Institute of Food and Agricultural Sciences, University of Florida, 359 FSHN Building, Newell Drive, Gainesville, Florida 32611, USA
| | - Aswathy Sreedharan
- Department of Food Science and Human Nutrition, Institute of Food and Agricultural Sciences, University of Florida, 359 FSHN Building, Newell Drive, Gainesville, Florida 32611, USA
| | - Keith R Schneider
- Department of Food Science and Human Nutrition, Institute of Food and Agricultural Sciences, University of Florida, 359 FSHN Building, Newell Drive, Gainesville, Florida 32611, USA.
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