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Louis D, Florence P, Ivan L, Anne-Gabrielle M. Detection of risk areas in dairy powder processes: The development of thermophilic spore forming bacteria taking into account their growth limits. Int J Food Microbiol 2024; 418:110716. [PMID: 38669747 DOI: 10.1016/j.ijfoodmicro.2024.110716] [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: 10/25/2023] [Revised: 04/16/2024] [Accepted: 04/21/2024] [Indexed: 04/28/2024]
Abstract
Anoxybacillus flavithermus, Geobacillus stearothermophilus and Bacillus licheniformis are the main contaminants found in dairy powders. These spore-forming thermophilic bacteria, rarely detected in raw milk, persist, and grow during the milk powder manufacturing process. Moreover, in the form of spores, these species resist and concentrate in the powders during the processes. The aim of this study was to determine the stages of the dairy powder manufacturing processes that are favorable to the growth of such contaminants. A total of 5 strains were selected for each species as a natural contaminant of dairy pipelines in order to determine the minimum and maximum growth enabling values for temperature, pH, and aw and their optimum growth rates in milk. These growth limits were combined with the environmental conditions of temperature, pH and aw encountered at each step of the manufacture of whole milk, skim milk and milk protein concentrate powders to estimate growth capacities using cardinal models and the Gamma concept. These simulations were used to theoretically calculate the population sizes reached for the different strains studied at each stage in between two successive cleaning in place procedures. This approach highlights the stages at which risk occurs for the development of spore-forming thermophilic bacterial species. During the first stages of production, i.e. pre-treatment, pasteurization, standardization and pre-heating before concentration, physico-chemical conditions encountered are suitable for the development and growth of A. flavithermus, G. stearothermophilus and B. licheniformis. During the pre-heating stage and during the first effects in the evaporators, the temperature conditions appear to be the most favorable for the growth of G. stearothermophilus. The temperatures in the evaporator during the last evaporator effects are favorable for the growth of B. licheniformis. In the evaporation stage, low water activity severely limits the development of A. flavithermus.
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Affiliation(s)
- Delaunay Louis
- Univ Brest, INRAE, Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, 29000 Quimper, France
| | - Postollec Florence
- ADRIA Food Technology Institute, UMT ACTIA 19.03 ALTER'iX, Z.A. de Creac'h Gwen, 29196, Quimper, Cedex, France
| | - Leguerinel Ivan
- Univ Brest, INRAE, Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, 29000 Quimper, France.
| | - Mathot Anne-Gabrielle
- Univ Brest, INRAE, Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, 29000 Quimper, France
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2
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Snyder AB, Martin N, Wiedmann M. Microbial food spoilage: impact, causative agents and control strategies. Nat Rev Microbiol 2024:10.1038/s41579-024-01037-x. [PMID: 38570695 DOI: 10.1038/s41579-024-01037-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/04/2024] [Indexed: 04/05/2024]
Abstract
Microbial food spoilage is a major contributor to food waste and, hence, to the negative environmental sustainability impacts of food production and processing. Globally, it is estimated that 15-20% of food is wasted, with waste, by definition, occurring after primary production and harvesting (for example, in households and food service establishments). Although the causative agents of food spoilage are diverse, many microorganisms are major contributors across different types of foods. For example, the genus Pseudomonas causes spoilage in various raw and ready-to-eat foods. Aerobic sporeformers (for example, members of the genera Bacillus, Paenibacillus and Alicyclobacillus) cause spoilage across various foods and beverages, whereas anaerobic sporeformers (for example, Clostridiales) cause spoilage in a range of products that present low-oxygen environments. Fungi are also important spoilage microorganisms, including in products that are not susceptible to bacterial spoilage due to their low water activity or low pH. Strategies that can reduce spoilage include improved control of spoilage microorganisms in raw material and environmental sources as well as application of microbicidal or microbiostatic strategies (for example, to products and packaging). Emerging tools (for example, systems models and improved genomic tools) represent an opportunity for rational design of systems, processes and products that minimize microbial food spoilage.
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Affiliation(s)
| | - Nicole Martin
- Department of Food Science, Cornell University, Ithaca, NY, USA
| | - Martin Wiedmann
- Department of Food Science, Cornell University, Ithaca, NY, USA.
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3
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Misiou O, Koutsoumanis K, Membré JM. Quantitative microbial spoilage risk assessment of plant-based milk alternatives by Geobacillus stearothermophilus in Europe. Food Res Int 2023; 166:112638. [PMID: 36914335 DOI: 10.1016/j.foodres.2023.112638] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 02/17/2023] [Accepted: 02/21/2023] [Indexed: 03/06/2023]
Abstract
Geobacillus stearothermophilus is one of the predominant spoilers of UHT-treated food products, due to its extremely heat-resistant spores. However, the surviving spores should be exposed to temperature higher than their minimum growth temperature for a certain time to germinate and grow to spoilage levels. Considering the projected temperature increase due to climate change, the events of non-sterility during distribution and transportation are expected to escalate. Hence, the aim of this study was to build a quantitative microbial spoilage risk assessment (QMRSA) model to quantify the risk of spoilage of plant-based milk alternatives within Europe. The model consists of four main steps: 1. Initial contamination of raw materials 2. Heat inactivation of spores during UHT treatment 3. Partitioning 4. Germination and outgrowth of spores during distribution and storage. The risk of spoilage was defined as the probability of G. stearothermophilus to reach its maximum concentration (Nmax = 107.5 CFU/mL) at the time of consumption. The assessment was performed for North (Poland) and South (Greece) Europe, and the risk of spoilage was estimated for the current climatic conditions and a climate change scenario. Based on the results, the risk of spoilage was negligible for the North European region, while the risk of spoilage in South Europe was 6.2 × 10-3 95% CI (2.3 × 10-3;1.1 × 10-2) under the current climatic conditions. The risk of spoilage was increased for both tested countries under climate change scenario; from zero to 1.0 × 10-4 in North Europe, risk multiplied 2 or 3 in South Europe depending on air conditioning implementation at consumer's place. Therefore, the heat treatment intensity and the use of insulated trucks during distribution were investigated as mitigation strategies and led to significant reduction of the risk. Overall, the QMRSA model developed in this study can support risk management decisions of these products by quantify the potential risk under current climatic conditions and climate change scenarios.
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Affiliation(s)
- Ourania Misiou
- Department of Food Science and Technology, Faculty of Agriculture, Aristotle University of Thessaloniki 54124 Thessaloniki, Greece
| | - Konstantinos Koutsoumanis
- Department of Food Science and Technology, Faculty of Agriculture, Aristotle University of Thessaloniki 54124 Thessaloniki, Greece
| | - Jeanne-Marie Membré
- Oniris, INRAE, Secalim, Site de la Chantrerie, CS 40706, 44307 Nantes Cédex 3, France.
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4
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Molinaro C, Bénéfice M, Gorlas A, Da Cunha V, Robert HML, Catchpole R, Gallais L, Forterre P, Baffou G. Life at high temperature observed in vitro upon laser heating of gold nanoparticles. Nat Commun 2022; 13:5342. [PMID: 36097020 PMCID: PMC9468142 DOI: 10.1038/s41467-022-33074-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 08/31/2022] [Indexed: 11/22/2022] Open
Abstract
Thermophiles are microorganisms that thrive at high temperature. Studying them can provide valuable information on how life has adapted to extreme conditions. However, high temperature conditions are difficult to achieve on conventional optical microscopes. Some home-made solutions have been proposed, all based on local resistive electric heating, but no simple commercial solution exists. In this article, we introduce the concept of microscale laser heating over the field of view of a microscope to achieve high temperature for the study of thermophiles, while maintaining the user environment in soft conditions. Microscale heating with moderate laser intensities is achieved using a substrate covered with gold nanoparticles, as biocompatible, efficient light absorbers. The influences of possible microscale fluid convection, cell confinement and centrifugal thermophoretic motion are discussed. The method is demonstrated with two species: (i) Geobacillus stearothermophilus, a motile thermophilic bacterium thriving around 65 °C, which we observed to germinate, grow and swim upon microscale heating and (ii) Sulfolobus shibatae, a hyperthermophilic archaeon living at the optimal temperature of 80 °C. This work opens the path toward simple and safe observation of thermophilic microorganisms using current and accessible microscopy tools. Studying microorganisms at high temperatures is challenging on conventional optical microscopes. Here, the authors introduce the concept of microscale laser heating over the full field of view by using gold nanoparticles as light absorbers, and study thermophile species up to 80 °C.
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5
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Koutsoumanis KP, Misiou OD, Kakagianni MN. Climate change threatens the microbiological stability of non-refrigerated foods. Food Res Int 2022; 162:111990. [DOI: 10.1016/j.foodres.2022.111990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 09/20/2022] [Accepted: 09/26/2022] [Indexed: 11/04/2022]
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6
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Park S, Cho T, Rhee M. Characterization of the nitrite production of mesophilic spore-forming bacteria during the handling of reconstituted infant formula. Food Res Int 2022; 156:111332. [DOI: 10.1016/j.foodres.2022.111332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Revised: 04/28/2022] [Accepted: 04/30/2022] [Indexed: 11/30/2022]
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7
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Misiou O, Zourou C, Koutsoumanis K. Development and validation of a predictive model for the effect of temperature, pH and water activity on the growth kinetics of Bacillus coagulans in non-refrigerated ready-to-eat food products. Food Res Int 2021; 149:110705. [PMID: 34600697 DOI: 10.1016/j.foodres.2021.110705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 08/31/2021] [Accepted: 09/02/2021] [Indexed: 10/20/2022]
Abstract
A cardinal model (CM) for the effects of temperature (range: 32-59 °C), pH (range: 5.0-8.5) and water activity (aw) (range: 0.980-0.995) on Bacillus coagulans DSM 1 growth rate was developed in brain heart infusion broth (BHI), using the Bioscreen C method and further validated in selected food products. The estimated values for the cardinal parameters Tmin, Topt, Tmax, pHmin, pHopt, pHmax, [Formula: see text] and [Formula: see text] were 23.77 ± 0.19 °C, 52.89 ± 0.01 °C, 59.37 ± 0.07 °C, 4.70 ± 0.02, 6.43 ± 0.02, 8.56 ± 0.01, 0.969 ± 0.0007 and 0.998 ± 0.0011, respectively. The growth behaviour of B. coagulans was studied in five commercial non-refrigerated ready-to-eat food products under static conditions at 53 °C in order to estimate the optimum specific growth rate for each tested food product. The developed models were validated in the five selected food products under four different dynamic temperature profiles by comparing predicted and observed growth behaviour of B. coagulans. The validation results indicated a good performance of the model for all tested products with the overall Bias factor (Bf) and Accuracy factor (Af) estimated at 1.00 and 1.12, respectively. The developed model can be considered an effective tool in predicting B. coagulans growth and spoilage risks of non-refrigerated ready-to-eat food products during distribution and storage.
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Affiliation(s)
- Ourania Misiou
- Laboratory of Food Microbiology and Hygiene, Department of Food Science & Technology, Faculty of Agriculture, Aristotle University, 54124 Thessaloniki, Greece
| | - Christina Zourou
- Laboratory of Food Microbiology and Hygiene, Department of Food Science & Technology, Faculty of Agriculture, Aristotle University, 54124 Thessaloniki, Greece
| | - Konstantinos Koutsoumanis
- Laboratory of Food Microbiology and Hygiene, Department of Food Science & Technology, Faculty of Agriculture, Aristotle University, 54124 Thessaloniki, Greece.
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8
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Alonso VPP, de Oliveira Morais J, Kabuki DY. Incidence of Bacillus cereus, Bacillus sporothermodurans and Geobacillus stearothermophilus in ultra-high temperature milk and biofilm formation capacity of isolates. Int J Food Microbiol 2021; 354:109318. [PMID: 34246014 DOI: 10.1016/j.ijfoodmicro.2021.109318] [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: 02/01/2021] [Revised: 06/02/2021] [Accepted: 06/19/2021] [Indexed: 12/19/2022]
Abstract
The presence of mesophilic and thermophilic spore-forming bacteria in UHT milk, as well as biofilm formation in dairy plants, are concerning. The current study explored the spore-forming bacilli diversity in 100 samples of UHT milk (skimmed and whole). Through this work, a total of 239 isolates from UHT milk samples were obtained. B. cereus s.s. was isolated from 7 samples, B. sporothermodurans from 19 and, G. stearothermophilus from 25 samples. Genes encoding hemolysin (HBL), and non-hemolytic (NHE) enterotoxins were detected in B. cereus s.s. isolates. All isolates of B. cereus s.s. (12) B. sporothermodurans (38), and G. stearothermophilus (47) were selected to verify the ability of biofilm formation in microtiter plates. The results showed all isolates could form biofilms. The OD595 values of biofilm formation varied between 0.14 and 1.04 for B. cereus, 0.20 to 1.87 for B. sporothermodurans, and 0.49 to 2.77 for G. stearothermophilus. The data highlights that the dairy industry needs to reinforce control in the initial quality of the raw material and in CIP cleaning procedures; avoiding biofilm formation and consequently a persistent microbiota in processing plants, which can shelter pathogenic species such as B. cereus s.s.
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Affiliation(s)
- Vanessa Pereira Perez Alonso
- Department of Food Science and Nutrition, School of Food Engineering, State University of Campinas, Campinas, SP, Brazil.
| | - Jéssica de Oliveira Morais
- Department of Food Science and Nutrition, School of Food Engineering, State University of Campinas, Campinas, SP, Brazil
| | - Dirce Yorika Kabuki
- Department of Food Science and Nutrition, School of Food Engineering, State University of Campinas, Campinas, SP, Brazil
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9
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Misiou O, Kasiouras G, Koutsoumanis K. Development and validation of an extended predictive model for the effect of pH and water activity on the growth kinetics of Geobacillus stearothermophilus in plant-based milk alternatives. Food Res Int 2021; 145:110407. [PMID: 34112410 DOI: 10.1016/j.foodres.2021.110407] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 04/06/2021] [Accepted: 05/06/2021] [Indexed: 11/17/2022]
Abstract
The cardinal model for the effect of temperature on Geobacillus stearothermophilus ATCC 7953 growth developed by Kakagianni, Gougouli, & Koutsoumanis, 2016 was expanded for the effect of pH and water activity (aw). The effect of pH (range: 5.7-8.5) and aw (range: 0.985-0.999) on G. stearothermophilus growth rate was studied in tryptone soy broth (TSB) using the Bioscreen C method and further modelled using a Cardinal Model (CM). The estimated values for the cardinal parameters [Formula: see text] , and [Formula: see text] were 5.65 ± 0.14, 6.74 ± 0.03, 8.71 ± 0.03, 0.984 ± 0.007 and 0.998 ± 0.001, respectively. The growth behaviour of G. stearothermophilus was investigated in 7 commercial non-refrigerated plant-based milk alternatives under static conditions (62 °C) and the estimated maximum specific growth rates were used to determine the optimum growth rate for each product. The developed model was validated against observed growth of G. stearothermophilus in the 7 products during storage at non-isothermal conditions (testing 4 different temperature profiles). The validation results showed a good performance of the model with overall Bias factor (Bf) = 1.06 and Accuracy factor (Af) = 1.12. The developed model can be used as an effective tool by the food industry in predicting spoilage of plant-based milk alternatives during distribution and storage at retail and domestic levels.
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Affiliation(s)
- Ourania Misiou
- Laboratory of Food Microbiology and Hygiene, Department of Food Science & Technology, Faculty of Agriculture, Aristotle University, 54124 Thessaloniki, Greece
| | - Georgios Kasiouras
- Laboratory of Food Microbiology and Hygiene, Department of Food Science & Technology, Faculty of Agriculture, Aristotle University, 54124 Thessaloniki, Greece
| | - Konstantinos Koutsoumanis
- Laboratory of Food Microbiology and Hygiene, Department of Food Science & Technology, Faculty of Agriculture, Aristotle University, 54124 Thessaloniki, Greece.
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10
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Misiou O, Koutsoumanis K. Climate change and its implications for food safety and spoilage. Trends Food Sci Technol 2021. [DOI: 10.1016/j.tifs.2021.03.031] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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11
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Dynamics of Geobacillus stearothermophilus and Bacillus cereus spores inoculated in different time intervals during simulated cocoa beans fermentation. Lebensm Wiss Technol 2020. [DOI: 10.1016/j.lwt.2019.108941] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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12
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Odeyemi OA, Alegbeleye OO, Strateva M, Stratev D. Understanding spoilage microbial community and spoilage mechanisms in foods of animal origin. Compr Rev Food Sci Food Saf 2020; 19:311-331. [PMID: 33325162 DOI: 10.1111/1541-4337.12526] [Citation(s) in RCA: 189] [Impact Index Per Article: 47.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 11/20/2019] [Accepted: 11/22/2019] [Indexed: 12/21/2022]
Abstract
The increasing global population has resulted in increased demand for food. Goods quality and safe food is required for healthy living. However, food spoilage has resulted in food insecurity in different regions of the world. Spoilage of food occurs when the quality of food deteriorates from its original organoleptic properties observed at the time of processing. Food spoilage results in huge economic losses to both producers (farmers) and consumers. Factors such as storage temperature, pH, water availability, presence of spoilage microorganisms including bacteria and fungi, initial microbial load (total viable count-TVC), and processing influence the rate of food spoilage. This article reviews the spoilage microbiota and spoilage mechanisms in meat and dairy products and seafood. Understanding food spoilage mechanisms will assist in the development of robust technologies for the prevention of food spoilage and waste.
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Affiliation(s)
- Olumide Adedokun Odeyemi
- Ecology and Biodiversity Centre, Institute for Marine and Antarctic Studies (IMAS), University of Tasmania, Launceston, Australia.,Food Safety and Quality Unit, Centre for Research, Training and Development, Higis International Foundation, Nigeria
| | | | - Mariyana Strateva
- Department of Veterinary Anatomy, Histology and Embryology, Faculty of Veterinary Medicine, Trakia University, Stara Zagora, Bulgaria
| | - Deyan Stratev
- Department of Food Hygiene and Control, Veterinary Legislation and Management, Faculty of Veterinary Medicine, Trakia University, Stara Zagora, Bulgaria
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13
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Diep B, Moulin J, Bastic-Schmid V, Putallaz T, Gimonet J, Valles AD, Klijn A. Validation protocol for commercial sterility testing methods. Food Control 2019. [DOI: 10.1016/j.foodcont.2019.03.029] [Citation(s) in RCA: 5] [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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14
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Pereira APM, Stelari HA, Carlin F, Sant’Ana AS. Inactivation kinetics of Bacillus cereus and Geobacillus stearothermophilus spores through roasting of cocoa beans and nibs. Lebensm Wiss Technol 2019. [DOI: 10.1016/j.lwt.2019.05.063] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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15
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Eijlander RT, van Hekezen R, Bienvenue A, Girard V, Hoornstra E, Johnson NB, Meyer R, Wagendorp A, Walker DC, Wells‐Bennik MHJ. Spores in dairy – new insights in detection, enumeration and risk assessment. INT J DAIRY TECHNOL 2019. [DOI: 10.1111/1471-0307.12586] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | | | | | | | - Erik Hoornstra
- Laboratory & Quality Services FrieslandCampina Leeuwarden The Netherlands
| | | | - Rolf Meyer
- Nestec Ltd. Nestlé Research & Development Konolfingen 3510 Switzerland
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16
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Pia AKR, Pereira APM, Costa RA, Alvarenga VO, Freire L, Carlin F, Sant'Ana AS. The fate of Bacillus cereus and Geobacillus stearothermophilus during alkalization of cocoa as affected by alkali concentration and use of pre-roasted nibs. Food Microbiol 2019; 82:99-106. [PMID: 31027825 DOI: 10.1016/j.fm.2019.01.009] [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] [Received: 07/18/2018] [Revised: 01/20/2019] [Accepted: 01/21/2019] [Indexed: 11/26/2022]
Abstract
Alkalization is a step of cocoa processing and consists of the use of alkali and high temperature to improve the sensorial and technological qualities of cocoa. Intense food processing can select spores, which can compromise safety and quality of the final product. Thus, the aim of this study was to evaluate the fate of B. cereus and G. stearothermophilus spores during the alkalization of pre-roasted (Pr) nibs (held at 120 °C) and unroasted (Ur) nibs (held at 90 °C) using potassium carbonate (0, 2, 4 and 6% w/w). In all conditions, log-linear inactivation kinetics with a tail was observed. The inactivation rate (kmax) for B. cereus varied from 0.065 to 1.67 min-1, whereas the kmax for G. stearothermophilus varied from 0.012 to 0.063 min-1. For both microorganisms, the lowest kmax values were observed during Ur nibs alkalization. The carbonate concentration increase promoted kmax values reduction. The highest tail values were observed for G. stearothermophilus in Ur nibs alkalization, reaching 3.04 log spores/g. Tail formation and low kmax values indicated that cocoa alkalization does not cause significant reductions on bacterial spore population. Therefore, the microbiological control should be primarily ensured by the raw material quality and by avoiding recontamination in the cocoa chain.
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Affiliation(s)
- Arthur K R Pia
- Department of Food Science, Faculty of Food Engineering, University of Campinas, Campinas, Brazil
| | - Ana P M Pereira
- Department of Food Science, Faculty of Food Engineering, University of Campinas, Campinas, Brazil
| | - Ramon A Costa
- Department of Food Science, Faculty of Food Engineering, University of Campinas, Campinas, Brazil
| | - Verônica O Alvarenga
- Department of Food Science, Faculty of Food Engineering, University of Campinas, Campinas, Brazil
| | - Luisa Freire
- Department of Food Science, Faculty of Food Engineering, University of Campinas, Campinas, Brazil
| | - Frédéric Carlin
- UMR408 SQPOV "Sécurité et Qualité des Produits d'Origine Végétale", INRA Avignon Université, 84000, Avignon, France
| | - Anderson S Sant'Ana
- Department of Food Science, Faculty of Food Engineering, University of Campinas, Campinas, Brazil.
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17
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Cho TJ, Rhee MS. Underrecognized niche of spore-forming bacilli as a nitrite-producer isolated from the processing lines and end-products of powdered infant formula. Food Microbiol 2018; 80:50-61. [PMID: 30704596 DOI: 10.1016/j.fm.2018.12.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 11/20/2018] [Accepted: 12/21/2018] [Indexed: 01/14/2023]
Abstract
Although nitrite in powdered milk formula (PIF) is a recognized health risk for infants, the presence of nitrite in PIF has only been investigated as a chemical contaminant during the inspection of end-products. The risk posed by microbial sources of nitrite during the PIF manufacturing process has not been considered. This is the first study to report the taxonomy and physiological characteristics of nitrite-producing bacteria isolated from PIF processing environments. All isolates identified as nitrite-producers (133 out of 501 strains collected over four years) from work-in-process and end-products of PIF were spore-forming bacilli. Nitrite-producing metabolism under PIF processing conditions was found in not only thermophilic isolates (3 Bacillus, 60 Geobacillus from 63 strains; 100%) but also in mesophilic isolates (65 Bacillus, 1 Anoxybacillus from 70 strains; 65.7%). Geobacillus was the only highly heat-resistant sporeformer and vigorous nitrite-producer exhibiting dramatic increases in nitrite over short periods of incubation (a maximum value within 3 h). High conversions of nitrate to nitrite (up to 88.8%) was also observed, highlighting bacteria as a key source of nitrite in PIF processing lines. Further research into the diversity of metabolic activity observed in this study can facilitate specialized management of nitrite-producers in PIF processing lines.
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Affiliation(s)
- Tae Jin Cho
- Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, 02841, South Korea
| | - Min Suk Rhee
- Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, 02841, South Korea.
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18
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Kakagianni M, Koutsoumanis KP. Mapping the risk of evaporated milk spoilage in the Mediterranean region based on the effect of temperature conditions on Geobacillus stearothermophilus growth. Food Res Int 2018; 111:104-110. [PMID: 30007665 DOI: 10.1016/j.foodres.2018.05.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 05/02/2018] [Accepted: 05/03/2018] [Indexed: 11/19/2022]
Abstract
A predictive model for the effect of storage temperature on the growth of Geobacillus stearothermophilus was applied in order to assess the risk of evaporated milk spoilage in the markets of the Mediterranean region. The growth of G. stearothermophilus in evaporated milk was evaluated during a shelf life of one year based on historical temperature profiles (hourly) covering 23 Mediterranean capitals for five years over the period 2012-2016 obtained from the Weather Underground database (http://www.wunderground.com/). In total, 115 scenarios were tested simulating the distribution and storage conditions of evaporated milk in the Mediterranean region. The highest growth of G. stearothermophilus was predicted for Marrakech, Damascus and Cairo over the period 2012-2016 with mean values of 7.2, 7.4 and 5.5 log CFU/ml, respectively, followed by Tunis, Podgorica and Tripoli with mean growth of 2.8, 2.4 and 2.3 log CFU/ml, respectively. For the rest 17 capitals the mean growth of the spoiler was <1.5 log CFU/ml. The capitals Podgorica, Cairo, Tunis and Ankara showed the highest variability in the growth during the 5 years examined with standard deviation values for growth of 2.01, 1.79, 1.77 and 1.25 log CFU/ml, respectively. The predicted extent and the variability of growth during the shelf life were used to assess the risk of spoilage which was visualised in a geographical risk map. The growth model of G. stearothermophilus was also used to evaluate adjustments of the evaporated milk expiration date which can reduce the risk of spoilage. The quantitative data provided in the present study can assist the food industry to effectively evaluate the microbiological stability of these products throughout distribution and storage at a reduced cost (by reducing sampling quality control) and assess whether and under which conditions (e.g. expiration date) will be able to export a product to a country without spoilage problems. This decision support may lead to a significant benefit for both the competitiveness of the food industry and the consumer.
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Affiliation(s)
- Myrsini Kakagianni
- Laboratory of Food Microbiology and Hygiene, Department of Food Science and Technology, School of Agriculture, Faculty of Agriculture, Forestry and Natural Environment, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece.
| | - Konstantinos P Koutsoumanis
- Laboratory of Food Microbiology and Hygiene, Department of Food Science and Technology, School of Agriculture, Faculty of Agriculture, Forestry and Natural Environment, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece.
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Kakagianni M, Kalantzi K, Beletsiotis E, Ghikas D, Lianou A, Koutsoumanis KP. Development and validation of predictive models for the effect of storage temperature and pH on the growth boundaries and kinetics of Alicyclobacillus acidoterrestris ATCC 49025 in fruit drinks. Food Microbiol 2018; 74:40-49. [PMID: 29706336 DOI: 10.1016/j.fm.2018.02.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 02/27/2018] [Accepted: 02/27/2018] [Indexed: 10/17/2022]
Abstract
This study was undertaken to provide quantitative tools for predicting the behavior of the spoilage bacterium Alicyclobacillus acidoterrestris ATCC 49025 in fruit drinks. In the first part of the study, a growth/no growth interface model was developed, predicting the probability of growth as a function of temperature and pH. For this purpose, the growth ability of A. acidoterrestris was studied at different combinations of temperature (15-45 °C) and pH (2.02-5.05). The minimum pH and temperature where growth was observed was 2.52 (at 35 and 45 °C) and 25 °C (at pH ≥ 3.32), respectively. Then a logistic polynomial regression model was fitted to the binary data (0: no growth, 1: growth) and, based on the concordance index (98.8%) and the Hosmer-Lemeshow statistic (6.226, P = 0.622), a satisfactory goodness of fit was demonstrated. In the second part of the study, the effects of temperature (25-55 °C) and pH (3.03-5.53) on A. acidoterrestris growth rate were investigated and quantitatively described using the cardinal temperature model with inflection and the cardinal pH model, respectively. The estimated values for the cardinal parameters Tmin, Tmax, Topt and pHmin, pHmax, pHopt were 18.11, 55.68, 48.60 °C and 2.93, 5.90, 4.22, respectively. The developed models were validated against growth data of A. acidoterrestris obtained in eight commercial pasteurized fruit drinks. The validation results showed a good performance of both models. In all cases where the growth/no growth interface model predicted a probability lower than 0.5, A. acidoterrestris was, indeed, not able to grow in the tested fruit drinks; similarly, when the model predicted a probability above 0.9, growth was observed in all cases. A good agreement was also observed between growth predicted by the kinetic model and the observed kinetics of A. acidoterrestris in fruit drinks at both static and dynamic temperature conditions.
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Affiliation(s)
- Myrsini Kakagianni
- Laboratory of Food Microbiology and Hygiene, Department of Food Science and Technology, School of Agriculture, Faculty of Agriculture, Forestry and Natural Environment, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - Kelly Kalantzi
- Department of Molecular Microbiology, Quality Assurance Division, Delta Foods S.A., 23rd km National Road Athens-Lamia, 145 65 Agios Stefanos, Greece
| | - Evangelos Beletsiotis
- Department of Molecular Microbiology, Quality Assurance Division, Delta Foods S.A., 23rd km National Road Athens-Lamia, 145 65 Agios Stefanos, Greece
| | - Dimitrios Ghikas
- Department of Molecular Microbiology, Quality Assurance Division, Delta Foods S.A., 23rd km National Road Athens-Lamia, 145 65 Agios Stefanos, Greece
| | - Alexandra Lianou
- Laboratory of Microbiology and Biotechnology of Foods, Department of Food Science and Human Nutrition, School of Food, Biotechnology and Development, Agricultural University of Athens, Iera Odos 75, Athens 11855, Greece
| | - Konstantinos P Koutsoumanis
- Laboratory of Food Microbiology and Hygiene, Department of Food Science and Technology, School of Agriculture, Faculty of Agriculture, Forestry and Natural Environment, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece.
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Kakagianni M, Aguirre JS, Lianou A, Koutsoumanis KP. Effect of storage temperature on the lag time of Geobacillus stearothermophilus individual spores. Food Microbiol 2017. [PMID: 28648296 DOI: 10.1016/j.fm.2017.04.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The lag times (λ) of Geobacillus stearothermophilus single spores were studied at different storage temperatures ranging from 45 to 59 °C using the Bioscreen C method. A significant variability of λ was observed among individual spores at all temperatures tested. The storage temperature affected both the position and the spread of the λ distributions. The minimum mean value of λ (i.e. 10.87 h) was observed at 55 °C, while moving away from this temperature resulted in an increase for both the mean and standard deviation of λ. A Cardinal Model with Inflection (CMI) was fitted to the reverse mean λ, and the estimated values for the cardinal parameters Tmin, Tmax, Topt and the optimum mean λ of G. stearothermophilus were found to be 38.1, 64.2, 53.6 °C and 10.3 h, respectively. To interpret the observations, a probabilistic growth model for G. stearothermophilus individual spores, taking into account λ variability, was developed. The model describes the growth of a population, initially consisting of N0 spores, over time as the sum of cells in each of the N0 imminent subpopulations originating from a single spore. Growth simulations for different initial contamination levels showed that for low N0 the number of cells in the population at any time is highly variable. An increase in N0 to levels exceeding 100 spores results in a significant decrease of the above variability and a shorter λ of the population. Considering that the number of G. stearothermophilus surviving spores in the final product is usually very low, the data provided in this work can be used to evaluate the probability distribution of the time-to-spoilage and enable decision-making based on the "acceptable level of risk".
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Affiliation(s)
- Myrsini Kakagianni
- Laboratory of Food Microbiology and Hygiene, Department of Food Science and Technology, School of Agriculture, Faculty of Agriculture, Forestry and Natural Environment, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - Juan S Aguirre
- Laboratorio de Microbiología y Probioticos, INTA, Universidad de Chile, Avenida El Líbano 5524, Macul, Santiago, Chile
| | - Alexandra Lianou
- Laboratory of Microbiology and Biotechnology of Foods, Department of Food Science and Human Nutrition, School of Food, Biotechnology and Development, Agricultural University of Athens, Iera Odos 75, Athens 11855, Greece
| | - Konstantinos P Koutsoumanis
- Laboratory of Food Microbiology and Hygiene, Department of Food Science and Technology, School of Agriculture, Faculty of Agriculture, Forestry and Natural Environment, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece.
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