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Berries represent an important fresh food commodity but are also used as dried or frozen ingredients added to many foods. Due to a number of foodborne outbreaks linked to frozen berries, the microbial safety of berry products has become a major food safety issue. The effect of gaseous ozone against selected strains was investigated in the present study at a laboratory scale. Among all the tested conditions, a 30 min treatment with 6 % wt/wt (ca. 80 g/m3) gaseous ozone delivered the highest reductions on fresh strawberries: 2.1, 1.5, 1.8 and 3.3-log reductions were achieved for Salmonella, E. faecium, MNV-1 and MS2, respectively. For frozen strawberries, a short exposure of 5 min to ozone gas resulted in 1.6, 0.7, 0.7 and 1.8-log reductions of Salmonella, E. faecium, MNV-1 and MS2, respectively. Salmonella appeared to be more sensitive than its surrogate E. faecium. Compared to MS2, MNV-1 was more resistant and thus may represent as a more suitable surrogate for human norovirus in validating gas treatment efficiency. No sensorial differences were detected after ozone treatment. Inactivation results using gaseous ozone on frozen berries was reported for the first time in the present study. Guidelines on reporting gaseous ozone data were proposed to help ensure the reproducibility and experimental transparency in inactivation studies. Data collected in the present study support the potential use of gaseous ozone as a sustainable decontamination technology for frozen strawberries at different stages of processing. Further optimization of ozone exposure in a pilot plant scale setting is needed to facilitate the future application of gaseous ozone during minimal processing of berries.

The use of chitosan for coagulation of artificial fresh-cut lettuce wash-water, made from butterhead lettuce and tap water, was assessed for reducing particulate and dissolved matter in order to improve the physicochemical quality, as such lowering the disinfectant demand and allowing longer reuse of postharvest wash-water. Chitosan was used to coagulate industrial leafy-vegetable wash-water from a processing company. Lowering the pH improved the reduction efficiency. Although the turbidity reduction was very high (>90%), virtually no dissolved organic matter was removed. Rapid sand filtration subsequent to coagulation resulted in more than 2 log reduction of aerobic psychrotrophic counts and total coliforms. Coagulation lowered the disinfectant demand (of free chlorine and peracetic acid) to some degree but had no positive impact on the trihalomethanes formation. As such, coagulation does not seem to be a viable option to lower the disinfection by-products, the disinfectant dose or the water use by itself. However, due to the efficient particle reduction by chitosan coagulation it shows potential to be used as a pretreatment for a subsequent biological treatment in a more developed water treatment system to allow water reuse in the fresh produce companies.

This study evaluated the decontamination of Pangasius fillets in chlorine or peracetic acid treated wash water. First, the decontamination efficacy of the washing step with chlorinated water applied by a Vietnamese processing company during trimming of Pangasius fillets was evaluated and used as the basis for the experiments performed on a laboratory scale. As chlorine was only added at the beginning of the batch and used continuously without renewal for 239 min; a rapid increase of the bacterial counts and a fast decrease of chlorine in the wash water were found. This could be explained by the rapid accumulation of organic matter (ca. 400 mg O 2 /L of COD after only 24 min). Secondly, for the experiments performed on a laboratory scale, a single batch approach (one batch of wash water for treating a fillet) was used. Chlorine and PAA were evaluated at 10, 20, 50 and 150 ppm at contact times of 10, 20 and 240 s. Washing with chlorine and PAA wash water resulted in a reduction of Escherichia coli on Pangasius fish which ranged from 0–1.0 and 0.4–1.4 log CFU/g, respectively while less to no reduction of total psychrotrophic counts, lactic acid bacteria and coliforms on Pangasius fish was observed. However, in comparison to PAA, chlorine was lost rapidly. As an example, 53–83% of chlorine and 15–17% of PAA were lost after washing for 40 s (COD = 238.2 ± 66.3 mg O 2 /L). Peracetic acid can therefore be an alternative sanitizer. However, its higher cost will have to be taken into consideration. Where (cheaper) chlorine is used, the processors have to pay close attention to the residual chlorine level, pH and COD level during treatment for optimal efficacy.

A methodology to i) assess the feasibility of water disinfection in fresh-cut leafy greens wash water and ii) to compare the disinfectant efficiency of water disinfectants was defined and applied for a combination of peracetic acid (PAA) and lactic acid (LA) and comparison with free chlorine was made. Standardized process water, a watery suspension of iceberg lettuce, was used for the experiments. First, the combination of PAA+LA was evaluated for water recycling. In this case disinfectant was added to standardized process water inoculated with Escherichia coli (E. coli) O157 (6logCFU/mL). Regression models were constructed based on the batch inactivation data and validated in industrial process water obtained from fresh-cut leafy green processing plants. The UV254(F) was the best indicator for PAA decay and as such for the E. coli O157 inactivation with PAA+LA. The disinfection efficiency of PAA+LA increased with decreasing pH. Furthermore, PAA+LA efficacy was assessed as a process water disinfectant to be used within the washing tank, using a dynamic washing process with continuous influx of E. coli O157 and organic matter in the washing tank. The process water contamination in the dynamic process was adequately estimated by the developed model that assumed that knowledge of the disinfectant residual was sufficient to estimate the microbial contamination, regardless the physicochemical load. Based on the obtained results, PAA+LA seems to be better suited than chlorine for disinfecting process wash water with a high organic load but a higher disinfectant residual is necessary due to the slower E. coli O157 inactivation kinetics when compared to chlorine.

Accessibility to abundant sources of high-quality water is integral to the production of safe and wholesome fresh produce. However, access to safe water is becoming increasingly difficult in many parts of the world, and this can lead to the production of fresh produce contaminated with pathogenic microorganisms, resulting in increased risk of human disease. Water, an important raw material in the fresh produce chain, is used in considerable amounts in many operations, including irrigation and application of pesticides and fertilizers, but also as a transport medium and for cooling and washing in postharvest practices. In several reported outbreaks related to uncooked fruit and vegetable products, water has been identified as a likely source of the outbreak. The present study, initiated by the ILSI Europe Emerging Microbiological Issues Task Force in collaboration with 8 other ILSI branches and support of WHO/FAO, was undertaken to review the status of, and provide suggestions for, consideration by different stakeholders on water and sanitation and its impact on food safety and public health. A limited number of guidelines and regulations on water quality for agricultural production are available, and many of them are still heavily based on microbial standards and (debated) parameters such as fecal coliforms. Data gaps have been identified with regard to baseline studies of microbial pathogens in water sources in many regions, the need for agreement on methods and microbial parameters to be used in assessing water quality, the fate of pathogens in water, and their transfer and persistence on irrigated/processed produce.

Hydrogen peroxide (H2O2) was used to maintain the microbial wash water quality of a full-scale leafy vegetables (radicchio, sugar loaf, curled endive, lollo, lollo rosso) wash water process. Despite addition of 300 L/h of 1.8% H2O2 to a 450 L washing bath (333 ± 50 kg/h fresh-cut produce introduction speed), the H2O2 quickly decreased and a lower wash water contamination of aerobic psychrotrophic plate count (APC) and enterococci than without addition of H2O2 could not be maintained. There was no significant difference between the APC on fresh-cut leafy vegetables washed with H2O2 and those washed with water. In a second part, lab-scale experiments were performed to assess the impact of a commercial metal ion formulation (Bacsan®, containing a. o. Cu2+, Zn2+, Ag+) on the stability of H2O2 in artificial wash water, made from iceberg lettuce and tap water. Bacsan improved the stability of H2O2 in artificial lettuce wash water and fresh-cut leafy vegetables wash water from a processing company and synergistically increased the disinfection efficiency of APC and Escherichia coli (E. coli) compared to H2O2 or Bacsan. Increasing chemical oxygen demand (COD) had detrimental effect on the H2O2 stability and disinfection efficiency. Addition of Ag+ to Bacsan further synergistically enhanced the H2O2 stability. H2O2 is not suited as an in situ wash water disinfectant to avoid cross-contamination in fresh-cut leafy vegetables washing processes due to the slow water disinfection kinetics and the rapid H2O2 consumption. However, H2O2/Bacsan shows potential for use in off-line processes.

Biofilms are an important source of contamination in food companies, yet the composition of biofilms in practice is still mostly unknown. The chemical and microbiological characterization of surface samples taken after cleaning and disinfection is very important to distinguish free-living bacteria from the attached bacteria in biofilms. In this study, sampling methods that are potentially useful for both chemical and microbiological analyses of surface samples were evaluated. In the manufacturing facilities of eight Belgian food companies, surfaces were sampled after cleaning and disinfection using two sampling methods: the scraper-flocked swab method and the sponge stick method. Microbiological and chemical analyses were performed on these samples to evaluate the suitability of the sampling methods for the quantification of extracellular polymeric substance components and microorganisms originating from biofilms in these facilities. The scraper-flocked swab method was most suitable for chemical analyses of the samples because the material in these swabs did not interfere with determination of the chemical components. For microbiological enumerations, the sponge stick method was slightly but not significantly more effective than the scraper-flocked swab method. In all but one of the facilities, at least 20% of the sampled surfaces had more than 102 CFU/100 cm2. Proteins were found in 20% of the chemically analyzed surface samples, and carbohydrates and uronic acids were found in 15 and 8% of the samples, respectively. When chemical and microbiological results were combined, 17% of the sampled surfaces were contaminated with both microorganisms and at least one of the analyzed chemical components; thus, these surfaces were characterized as carrying biofilm. Overall, microbiological contamination in the food industry is highly variable by food sector and even within a facility at various sampling points and sampling times.

With growing interest in essential oils as natural preservatives in the food industry, the literature is expanding enormously. To understand the antimicrobial activity of essential oils, the antimicrobial mechanism of individual essential oil (EO) compounds, and their minimum inhibitory concentrations (MICs), are interesting starting points for research. Therefore, and to get insight into the factors influencing their antimicrobial activities, the Web of Science was searched for MICs of EO compounds (1995-2016). Many MICs for individual EO compounds have already been reported in the literature, but there is large variability in these data, even for the MIC of the same compound against the same species. No correlation was found between the tested structural parameters of EO compounds (polarity, water solubility, dissociation constant, molecular weight and molecular complexity) and their MICs against all microorganisms, Gram-negative bacteria, Gram-positive bacteria and fungi. Few clear differences in sensitivity between microorganisms could be found. Based on this review it is clear that different incubation conditions, culture media and the use of emulsifiers/solvents have an influence on the MIC, causing big variance. This review points out the need for a good international standard method to assess the antimicrobial activity of EO compounds for better comparability between studies.

This paper comprises a selection tool for water disinfection methods for fresh produce pre- and postharvest practices. A variety of water disinfection technologies is available on the market and no single technology is the best choice for all applications. It can be difficult for end users to choose the technology that is best fit for a specific application. Therefore, the different technologies were characterized in order to identify criteria that influence the suitability of a technology for pre- or postharvest applications. Introduced criteria were divided into three principal components: (i) criteria related to the technology and which relate to the disinfection efficiency, (ii) attention points for the management and proper operation, and (iii) necessities in order to sustain the operation with respect to the environment. The selection criteria may help the end user of the water disinfection technology to obtain a systematic insight into all relevant aspects to be considered for preliminary decision making on which technologies should be put to feasibility testing for water disinfection in pre- and postharvest practices of the fresh produce chain.

In January 2011, a workshop was organized by the EU FP7 Veg-i-Trade project to capture opinions of stakeholders on food safety issues in the global fresh produce supply chain. Food safety experts from various stakeholder types in the farm-to-fork chain were represented: farmer related organizations (n = 6), fresh produce processing and trading companies (n = 17), retail (n = 3), consumer organizations (n = 2), competent authorities (n = 7) and lastly research institutes and universities (n = 19). The experts who originated mainly from European countries (92.6%) were grouped in nine discussion groups per type of stakeholder and asked to rank food safety issues via a scoring approach according to perceived importance from their stakeholder type point of view. Also information sources for opinion making, appropriate food safety control measures and perceived contextual factors increasingly challenging governance of food safety in fresh produce were ranked according to perceived importance. Although some differences were noted between opinions of the different stakeholders, there was in general an agreement on the main priorities in food safety of fresh produce. Bacterial pathogens were overall considered to be the most important food safety issue for fresh produce, followed by foodborne viruses, pesticide residues and mycotoxins. Alert systems such as the European Commission's Rapid Alert System for Food and Feed (RASFF) were considered as the most important source of information of food safety issues, followed by reports of international organizations (e.g. WHO, EFSA), legislative documents (e.g. EU legislation), national reports (e.g. on monitoring hazards, foodborne outbreaks) and exchange of information between people (informal contacts). Concerning the control measures, the application of good agricultural practices (GAP) was identified to be the most important control measure to assure the safety of fresh produce, followed by the application of good hygienic practices (GHP) and the certification of food safety management systems (FSMS). Increasing international trade and globalization were overall expected to have a large impact on food safety in fresh produce. Other contextual factors perceived to be important were the food safety policies by governments and the (lack of) food safety knowledge by consumers and other stakeholders of the fresh produce supply chain. Although the various stakeholder groups may conceive issues differently from their proper position in the fresh produce supply chain, no deep disagreements emerged. This type of workshop enhances interaction and risk communication between stakeholders and contributes to a better understanding of each other's concerns, constraints and interests to deal with the food safety of the increasingly complex and globalized fresh produce supply chain.

A survey was set-up using a web-application supplemented with a print-out questionnaire to gather knowledge on consumption patterns and consumer behaviour in the storage and preparation of poultry meat, in particular poultry meat preparations for Belgian adults. In total 1618 respondents were reached. The survey included questions on risk factors associated with campylobacteriosis i.e. storage conditions, potential for cross-contamination and undercooking. Almost 61% of the respondents have identified home freezing of fresh poultry meat as a common storage technique. Several cross-contamination routes in the kitchen are confirmed, e.g. putting cooked poultry meat at the same plate of the raw poultry meat (11.2%), not washing hands after handling raw poultry meat (11%), using the same knife (6.7%) or cutting board (8.2%) for the vegetables which was prior used for the poultry meat. Although the majority of the respondents indicated to eat their poultry meat well-cooked (96% for poultry meat preparations to 98.4% for broiler), 16% would eat not well-cooked poultry meat if served at a barbecue. Poultry parts not marinated or seasoned was ranked as eaten the most, followed by broiler and next meat preparations (with first the marinated/seasoned poultry cuts and second the minced poultry meat preparations). The gathered consumer data may now be incorporated into a retail to fork quantitative risk assessment model for poultry meat preparations to estimate the risk for campylobacteriosis to the Belgian consumer and to enable the evaluation of risk mitigation strategies (to support risk managers) in the consumer phase. A proper comparison of the contribution of the different pathways to consumers’ exposure (i.e. effect of freezing during storage, prevalence of undercooking and cross-contamination) to Campylobacter bacteria may now be performed.

This study provided insight into the degree of microbial contamination in the processing chain of prepacked (bagged) lettuce in two Belgian fresh-cut produce processing companies. The pathogens Salmonella and Listeria monocytogenes were not detected. Total psychrotrophic aerobic bacterial counts (TPACs) in water samples, fresh produce, and environmental samples suggested that the TPAC is not a good indicator of overall quality and best manufacturing practices during production and processing. Because of the high TPACs in the harvested lettuce crops, the process water becomes quickly contaminated, and subsequent TPACs do not change much throughout the production process of a batch. The hygiene indicator Escherichia coli was used to assess the water management practices in these two companies in relation to food safety. Practices such as insufficient cleaning and disinfection of washing baths, irregular refilling of the produce wash baths with water of good microbial quality, and the use of high product/water ratios resulted in a rapid increase in E. coli in the processing water, with potential transfer to the end product (fresh-cut lettuce). The washing step in the production of fresh-cut lettuce was identified as a potential pathway for dispersion of microorganisms and introduction of E. coli to the end product via cross-contamination. An intervention step to reduce microbial contamination is needed, particularly when no sanitizers are used as is the case in some European Union countries. Thus, from a food safety point of view proper water management (and its validation) is a critical point in the fresh-cut produce processing industry.

A diagnostic instrument comprising a combined assessment of core control and assurance activities and a microbial assessment instrument were used to measure the performance of current food safety management systems (FSMSs) of two poultry meat preparation companies. The high risk status of the company's contextual factors, i.e., starting from raw materials (poultry carcasses) with possible high numbers and prevalence of pathogens such as Campylobacter spp., requires advanced core control and assurance activities in the FSMS to guarantee food safety. The level of the core FSMS activities differed between the companies, and this difference was reflected in overall microbial quality (mesophilic aerobic count), presence of hygiene indicators (Enterobacteriaceae, Staphylococcus aureus, and Escherichia coli), and contamination with pathogens such as Salmonella, Listeria monocytogenes, and Campylobacter spp. The food safety output expressed as a microbial safety profile was related to the variability in the prevalence and contamination levels of Campylobacter spp. in poultry meat preparations found in a Belgian nationwide study. Although a poultry meat processing company could have an advanced FSMS in place and a good microbial profile (i.e., lower prevalence of pathogens, lower microbial numbers, and less variability in microbial contamination), these positive factors might not guarantee pathogen-free products. Contamination could be attributed to the inability to apply effective interventions to reduce or eliminate pathogens in the production chain of (raw) poultry meat preparations.

The aim of this study was to gain insight into potential differences in risk factors for microbial contamination in greenhouse versus open field lettuce production. Information was collected on sources, testing, and monitoring and if applicable, treatment of irrigation and harvest rinsing water. These data were combined with results of analysis on the levels of Escherichia coli as a fecal indicator organism and the presence of enteric bacterial pathogens on both lettuce crops and environmental samples. Enterohemorragic Escherichia coli (EHEC) PCR signals (vt1 or vt2 positive and eae positive), Campylobacter spp., and Salmonella spp. isolates were more often obtained from irrigation water sampled from open field farms (21/45, 46.7%) versus from greenhouse production (9/75, 12.0%). The open field production was shown to be more prone to fecal contamination as the number of lettuce samples and irrigation water with elevated E. coli was significantly higher. Farmers comply with generic guidelines on good agricultural practices available at the national level, but monitoring of microbial quality, and if applicable appropriateness of water treatment, or water used for irrigation or at harvest is restricted. These results indicate the need for further elaboration of specific guidelines and control measures for leafy greens with regard to microbial hazards.

This study aimed to gain an insight in the performance of Hazard Analysis and Critical Control Points (HACCP)-based food safety management systems (FSMS) implemented in Japanese milk processing plants. Since 1995, Japan has a comprehensive approval system for food manufacturing establishments by evaluating the development and implementation of GHP and HACCP by the food manufacturing companies/operators. An FSMS-diagnostic instrument was applied to assess the level of the core control and assurance activities in the FSMS and to judge the risk level of the context wherein the companies operate. The data were collected in 13 dairy companies (mostly located around Tokyo area) and involved in-depth interviews performed (by the National Institute of Public Health) with responsible quality assurance persons of respective companies. The results revealed that the microbial food safety output was higher for companies with national HACCP approval. They have more advanced FSMS in combination with a less risky context. All Japanese companies scored high on technology-dependent activities (i.e. preventive measures and intervention processes), but less in managerial activities as monitoring and typical quality assurance activities as validation and verification of the FSMS. Japan has a detailed vertical legislation, leading to a “hazard-based” and ”legislation-based” FSMS compared to a “science- or risk-based” FSMS common in Europe.

AIMS: To estimate the true prevalence of Campylobacter and the diagnostic sensitivity of routine detection methods by applying a Bayesian modelling approach. METHODS AND RESULTS: Results from a Belgium-wide survey of Campylobacter contamination in chicken meat preparations (n = 656 samples) showed that Campylobacter was detected in 24.2% of the samples by enrichment, compared with 41% detected by direct plating. Combining positive results from both methods increased the apparent prevalence to 48.02%. Bayesian model was set up in WinBUGS software, the model estimates Campylobacter prevalence as 60% (95% Credibility interval (CI): 47-82%), and the sensitivity of enrichment culture and direct plating as 41% (95% CI: 31-52%) and 69% (95% CI: 50-85%), respectively. CONCLUSIONS: The parallel use of direct plating and enrichment culture adds value for Campylobacter detection from chicken meat preparations, but the false-negative results from each culture method must be taken into account. SIGNIFICANCE AND IMPACT OF THE STUDY: Monitoring data could be strongly biased by the microbiological techniques used to generate it. To circumvent this bias, we describe an applied Bayesian framework for better interpretation of Campylobacter survey data in view of the imperfect test characteristics of routine culture methods.

The aim of this study was to obtain insight into processing practices in the poultry sector contributing to the variability in Campylobacter contamination in Belgian chicken meat preparations. This was achieved by company profiling of eleven food business operators, in order to evaluate variation of processing management, in addition to statistical modelling of microbiological testing results for Campylobacter spp. contamination in 656 end product samples. Almost half (48%) of chicken meat preparation samples were positive for Campylobacter spp. Results revealed a statistically significant variation in Campylobacter contamination between 11 chicken meat producers across Belgium at both quantitative and qualitative detection levels. All producers provided Campylobacter-positive samples, but prevalence ranged from 9% up to 85% at single producer level. The presence or addition of skin during production of chicken meat preparations resulted in almost 2.2-fold increase in the probability of a sample being positive for Campylobacter, while chicken meat preparations made from frozen meat, or partly containing pre-frozen meat, had a significant (Odds Ratio=0.41; CI 95% 0.18:0.98) lower probability of being positive for Campylobacter. However, the quantitative results indicated that the positive freezing effect on Campylobacter count was compromised by the presence and/or adding of skin.