Two alternatives of computational models to simulate the contamination has been produced in the Mat Lab. The models are based on the transfer of bacteria between the hands, chicken, knife, cutting board, salad, and tap and also reduction of bacteria by washing the cutting board, and growth on cutting board. The input of the transmission, reduction and growth have been adopted on the basis of support from the literature data. In the simpler contamination model the contamination is only calculated in one direction. In the more complex model the transfer of bacteria that occurs from both sides at a touch has been taken into account, ie, if a person touch a cutting board, bacteria is transferred from the hand to the cutting board and also from the cutting board to the hand. Calculations were performed with matrix calculation. The results from the two models differ in the simulations. The more repeated contacts taken with the more bacteria spread from a contaminated hand at the start of the scenario to the final product. Models provide a guide to the factors in the spread of bacteria that are most important.

Under primärproduktionen och vidareförädling via torkning av kryddor kan kontamination ske med sjukdomsframkallande mikroorganismer, vilket kan orsaka att personer som konsumerar produkter blir sjuka. Det är inte säkert att vidare behandling av kryddorna såsom värme sker innan konsumtion och därmed sker ingen reduktion av mikroorganismer. Kryddorna kan, om de är råvara i andra produkter och om de är kontaminerade med sjukdomsframkallande mikroorganismer, kontaminera de nya produkterna. För att minska sannolikheten att detta sker måste smittkällor och spridningsvägar kontrolleras och styras i möjligaste mån. Detta innebär att det måste finnas effektiva grundförutsättningar, det vill säga rutiner för hur odling, bevattning, gödsling, skörd, torkning, lagring med mera utförs för att minimera den mikrobiologiska kontamineringen och tillväxten av mikroorganismer på kryddorna. Om man med dessa grundförutsättningar som bas i processen utför en faroanalys och implementerar åtgärder för att styra farorna enligt HACCP-metodiken får man säkra kryddor som inte medför någon fara för slutkonsumenten oavsett användning.

Salmonella is an important cause of bacterial foodborne infections in Denmark. To identify the main animal-food sources of human salmonellosis, risk managers have relied on a routine application of a microbial subtyping-based source attribution model since 1995. In 2013, multiple locus variable number tandem repeat analysis (MLVA) substituted phage typing as the subtyping method for surveillance of S. Enteritidis and S. Typhimurium isolated from animals, food, and humans in Denmark. The purpose of this study was to develop a modeling approach applying a combination of serovars, MLVA types, and antibiotic resistance profiles for the Salmonella source attribution, and assess the utility of the results for the food safety decisionmakers. Full and simplified MLVA schemes from surveillance data were tested, and model fit and consistency of results were assessed using statistical measures. We conclude that loci schemes STTR5/STTR10/STTR3 for S. Typhimurium and SE9/SE5/SE2/SE1/SE3 for S. Enteritidis can be used in microbial subtyping-based source attribution models. Based on the results, we discuss that an adjustment of the discriminatory level of the subtyping method applied often will be required to fit the purpose of the study and the available data. The issues discussed are also considered highly relevant when applying, e.g., extended multi-locus sequence typing or next-generation sequencing techniques.

There is currently a need in developing new decontamination technologies for spices due to limitations of existing technologies, mainly regarding their effects on spices’ sensory quality. In the search of new decontamination solutions, it is of interest to compare different technologies, to provide the industry with knowledge for taking decisions concerning appropriate decontamination technologies for spices. The present study compares infrared (IR) and microwave decontamination of naturally contaminated paprika powder after adjustment of water activity to 0.88. IR respectively microwave heating was applied to quickly heat up paprika powder to 98°C, after which the paprika sample was transferred to a conventional oven set at 98°C to keep the temperature constant during a holding time up to 20 min. In the present experimental set-up microwave treatment at 98°C for 20 min resulted in a reduction of 4.8 log units of the total number of mesophilic bacteria, while the IR treatment showed a 1 log unit lower reduction for the corresponding temperature and treatment time. Microwave and IR heating created different temperature profiles and moisture distribution within the paprika sample during the heating up part of the process, which is likely to have influenced the decontamination efficiency. The results of this study are used to discuss the difficulties in comparing two thermal technologies on equal conditions due to differences in their heating mechanisms

When new food processing technologies are investigated as alternative to traditional thermal pasteurization processes, conventional cultivation-based methods are usually applied to evaluate microbial concentration before and after the treatment to determine the process efficiency. However, these standard methods lead to a typical underestimation of the microbes present in the sample, which may represent an issue when pathogenic strains have to be detected. Here, the efficiency of SC-CO2 pasteurization treatment in the inactivation of Listeria monocytogenes spiked on cured ham skin surface was evaluated using plate counts, flow cytometry (FCM) coupled with SYBR-Green I (SYBR-I) and propidium iodide (PI), and propidium monoazide quantitative PCR (PMA-qPCR), at different process conditions. SC-CO2 best performed at 12 MPa, 45 and 50 °C, resulting in a 7.5 log reduction of cultivable cells quantified by plate counts after 15 min of treatment, while FCM and PMA-qPCR revealed a 4 log and 2 log reduction of intact cells, respectively. This striking difference between culture-based and culture-independent quantification methods was independent from treatment time and indicated that a large fraction of the cells lost cultivability after treatment but maintained an intact membrane, likely entering in a so-called Viable But Not Culturable (VBNC) state. Our study highlights the usefulness of FCM and PMA-qPCR to assess the viability status of microbial populations and support their application in microbiological quality control in the food industry, in particular when mild pasteurization technologies are used.

The objective of this study was to investigate the inter-relationships between changes in beef color and microbial growth when steaks from longissimus thoracis et lumborum muscles were overwrapped with polyvinyl chloride film and stored at 4°C. At day 0, 4, 7 and 10 instrumental color (CIE L*, a*, b* and spectral scans) and microbial counts were measured. Bacterial communities were characterized through Terminal Restriction Fragment Length Polymorphism analysis. Both meat discoloration and microbial spoilage occurred at day 10. Total viable count, Enterobacteriaceae count and the relative abundance of Pseudomonas spp. and Acinetobacter spp. were significantly correlated with color metrics associated with discoloration. These findings indicate that meat discoloration and microbial growth may not be totally independent effects and changes in a*, Chroma and hue angle may be an indicator of meat spoilage under this specific storage condition. Meanwhile, Enterobacteriaceae and aerobic bacteria might play important roles in meat discoloration.

The purpose of the project has been to identify how date labelling legislation on food is practised in Denmark, Finland, Norway and Sweden and how the durability can be affected in the food supply chain. The project recommends enhanced guidance for manufacturers, retailers and consumers.