Modelling the fate of Listeria Monocytogenes in Beef Meat Stored at Refrigeration Temperatures under Different Packaging Conditions
The objective of this study was to model the fate of L. monocytogenes inoculated in beef at two concentrations (2.5 and 4.0 log CFU/g), packaged under aerobic, vacuum and three modified atmosphere combinations – 70%O2/20%CO2/10%N2, 50%O2/40%C O2/10%N2 and 30%O2/60%CO2/10%N2, and refrigerated at a normal temperature (4°C) and at a mild abuse temperature (9°C). An omnibus model based on the three-parameter Weibull equation proved statistically that L. monocytogenes survives better in vacuum (VP) than in aerobic conditions, although without significant difference in its ability to survive in the temperature range between ...
Source: Procedia Food Science - October 28, 2016 Category: Food Science Source Type: research
The Antimicrobial Effect of Rosemary and Thyme Essential Oils Against Listeria Monocytogenes in Sous Vide Cook-chill Beef During Storage
Publication date: 2016 Source:Procedia Food Science, Volume 7 Author(s): Ana Rita Gouveia, Márcio Alves, José António Silva, Cristina Saraiva Sous vide cook-chill (SVCC) is a technology characterized by vacuum-packaging of raw or partially prepared foods before pasteurization, followed by rapid chilling and storage below 3°C. The application of essential oils (EOs) is a strategy to control pathogens and to extend the shelf life of products by reducing microbial levels and oxidative processes. The aim of this study was to evaluate the efficacy of Rosmarinus officinalis L. (rosemary) Thymus vulgaris L. (thyme) EOs ...
Source: Procedia Food Science - October 28, 2016 Category: Food Science Source Type: research
Modelling the Growth of Salmonella spp. and Escherichia Coli O157 on Lettuce
This study aimed to model the growth of Salmonella and Escherichia coli O157 on lettuce at different temperatures. Microorganisms were inoculated separately on lettuce and stored at 5, 10, 25, and 37°C. Growth curves were built by fitting the data to the Baranyi's DMFit model and Ratkowsky equation was used as secondary model. The models were able to assess the growth of both microorganisms and data showed that bacteria did not growth for 24hours at 10°C, what can be a suitable temperature for lettuce distribution on food services. However, prolonged periods demonstrated growth at every temperatures examined. (Source: Procedia Food Science)
Source: Procedia Food Science - October 28, 2016 Category: Food Science Source Type: research
Develop Mechanistic Models of Transition Periods between Lag/Exponential and Exponential/Stationary Phase
Publication date: 2016 Source:Procedia Food Science, Volume 7 Author(s): Yangyang Wang, Robert L. Buchanan A continuing goal in predictive microbiology is models directly based on physiological behavior. Buchanan et al.1 hypothesized that (1) the curvilinear lag/exponential transition represents the variability of cells in the adjustment (ta) and metabolic (tm) periods, and (2) the exponential/stationary transition is determined by limiting nutrient diffusion rates. Nutritional shift trials were conducted to estimate E.coli K-12 growth. Lactase production time suggest that lactase gene translation occurs after completi...
Source: Procedia Food Science - August 12, 2016 Category: Food Science Source Type: research
Quantifying the Impact of Biological and Experimental Variability Near the Growth Boundaries on the Stochastic Responses of Growth, Gene Transcription and Acid Resistance of Listeria monocytogenes
Publication date: 2016 Source:Procedia Food Science, Volume 7 Author(s): P.I. Makariti, D. Siderakou, N.P. Skandamis Hereby, we showed that the experimental and biological variability in culture preparation had little effect on the stochastic outcome of: (i) growth, (ii) relative transcription of stress- (gad2, sigB) and virulence- (prfA) associated genes and (iii) subsequent acid resistance of Listeria monocytogenes, across growth/ no growth boundaries regarding combinations of pH (4.8-7.2) (HCl) and NaCl (0-8% w/v) at 7oC. Variability of bacterial response, as described by the coefficient of variation (CV) and root ...
Source: Procedia Food Science - August 12, 2016 Category: Food Science Source Type: research
Predictions of Microbial Thermal Inactivation in Solid Foods: Isothermal and Non-isothermal Conditions
Publication date: 2016 Source:Procedia Food Science, Volume 7 Author(s): Maria M. Gil, Fátima A. Miller, Teresa R.S. Brandão, Cristina L.M. Silva This work focuses on the use of the Gompertz-inspired model to predict the thermal inactivation behaviour of microorganisms obtained in solid food products, validated for isothermal and non-isothermal conditions. Experiments were carried out in parsley, artificially inoculated with Listeria innocua. For the isothermal conditions tested, the predictive ability of the model was confined. The higher the temperature, the higher deviations observed (i.e. the model underestimat...
Source: Procedia Food Science - August 12, 2016 Category: Food Science Source Type: research
A Web-based Application Customized to Food Safety Requirements of Small-sized Enterprises
Publication date: 2016 Source:Procedia Food Science, Volume 7 Author(s): Pierluigi Polese, Manuela Del Torre, Mara Lucia Stecchini Today, European legislation considers predictive microbiology as a tool to define food safety. People in the food industry, including those in small-sized enterprises, even if they are unable to avail themselves of specific knowledge, are encouraged to use the same approach. To extend a bridge between both sides, a user-friendly, simplified, web-based application (Praedicere Possumus, PP) has been developed. Through this application, users have access to different modules, which apply a se...
Source: Procedia Food Science - August 12, 2016 Category: Food Science Source Type: research
Modeling the Enhanced Thermal Inactivation of Cronobacter sakazakii by Inclusion of “Parabens”
Publication date: 2016 Source:Procedia Food Science, Volume 7 Author(s): Luxi Ruan, Robert L. Buchanan The goal of this study is to develop mathematical models that describe the enhanced thermal inactivation of Cronobacter sakazakii by the inclusion of “parabens”. The key parameters include heating temperature, parabens concentration, and the length of parabens’ alkyl side chains. The heating trials were conducted in a submerged coil apparatus using Brain Heart Infusion (BHI) as the model heating menstruum. The results clearly demonstrated that a significant enhancement of thermal inactivation is concentration de...
Source: Procedia Food Science - August 12, 2016 Category: Food Science Source Type: research
Analysis of Vacuum Packed Beef Regarding Psychrotrophic Bacteria Growth and Biogenic Amines Content
Publication date: 2016 Source:Procedia Food Science, Volume 7 Author(s): M.G. Marquezini, E.A. Orlando, S.E. Yotsuyanagi, R. Bromberg It has been recognized that biogenic amines (BA) content in meat can be considered a freshness marker. Considerable amounts of some BAs can appear during food storage under certain conditions, according to the handling of the raw material, technology applied, storage temperature and time, packaging condition, mainly if amino acid - decarboxylase positive microorganisms are present. The aim of this study was to evaluate the psychrotrophic bacteria growth and metabolic production of BAs ...
Source: Procedia Food Science - August 12, 2016 Category: Food Science Source Type: research
Estimation of the Risk Associated to Marketing of Swine Meat Contaminated with Salmonella spp., Employing the William T. Fine Method
Publication date: 2016 Source:Procedia Food Science, Volume 7 Author(s): Nataly Ruiz Quiñones, Oscar Castro Aguilar, Martha Lily Ocampo Guerrero Swine meat is a growing market in Colombia, reaching 3.1 million of carcasses sold in 2014. However, it is estimated that the proportion of hogs illegally marketed can be up to 50%, which exposes the population to foodborne pathogens such as Salmonella. The aim of this study was to estimate the risk associated to the marketing of swine meat contaminated with Salmonella, using the William T. Fine method in Tolima Department. The risk scenarios applied to four municipalities p...
Source: Procedia Food Science - August 12, 2016 Category: Food Science Source Type: research
Predictive Microbiology Models and Operational Readiness
The objectives of this work were (i) to review current approaches in predictive microbiology used to build, verify and validate models, and (ii) to propose a categorization scheme that would tend to define a model's viability for use in an operational setting. (Source: Procedia Food Science)
Source: Procedia Food Science - August 12, 2016 Category: Food Science Source Type: research
Dose-response Modelling of Staphylococcal Enterotoxins Using Outbreak Data
The objective of this work was to build a dose response relation based on the systematic investigations carried out during recent years in France. Over the period 2010-2014, more than 60 SFP outbreaks involving SEs, mainly from France, were microbiologically investigated. The enterotoxins were characterized as well as quantified. Attack rates, appearance times and natures of symptoms collected during epidemiological investigations were related to microbiological data. The outbreaks collected focused on enterotoxins SEA, SEB, SEC, and SED. Distribution of appearance times of symptoms and their natures were not influenced by...
Source: Procedia Food Science - August 12, 2016 Category: Food Science Source Type: research
Is Food Safety Compatible with Food Waste Prevention and Sustainability of the Food Chain?
The objective of this work was to develop a global model for a ready-to-eat meat product that provides three different outputs, i.e. energy consumption, percentage of spoiled products and exposure levels of Listeria monocytogenes. First a cold chain model was developed. The cold chain model was then coupled with (i) predictive microbiology models and (ii) energy consumption models for cold equipments. Various scenarios were tested for assessing the consequences of potential changes in cold chain equipment on safety, food waste and energy cost. This global approach could help policy makers in decision making. (Source: Procedia Food Science)
Source: Procedia Food Science - August 12, 2016 Category: Food Science Source Type: research
A Predictive Modelling Study for Using High Hydrostatic Pressure, a Food Processing Technology, for Protein Extraction
Publication date: 2016 Source:Procedia Food Science, Volume 7 Author(s): Ergin Murat Altuner The aim of this study is to fit a response model to one response, extracted protein concentration by using high hydrostatic pressure, a food processing technology, as a function of two particular controllable factors of extraction procedure. These factors are “pressure” (applied in MPa) and the “extraction solvent”. Data were taken from a previously published data, where the minimum and maximum values chosen for pressure were 100MPa and 300MPa with a center point of 200MPa. The solvents were PBS, TCA-Acetone and Tris-HCl...
Source: Procedia Food Science - August 12, 2016 Category: Food Science Source Type: research
F-value Calculator – A Tool for Calculation of Acceptable F-value in Canned Luncheon Meat Reduced in NaCl
We describe a new tool for calculating the F-value, necessary to obtain equivalent safety for canned meat when reduced in NaCl, compared to the original combination of aqueous salt and F–value. The tool is valid for combinations of F–values between 0.51 and 3.25 and aqueous salt between 1.66 and 3.54%. The tool is available at http://dmripredict.dk. (Source: Procedia Food Science)
Source: Procedia Food Science - August 12, 2016 Category: Food Science Source Type: research
