Semi-quantitative study to evaluate the performance of a HACCP-based food safety management system in Japanese milk processing plants

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.     

Influence of partial inactivation on growth of Listeria monocytogenes under sub-optimal conditions of increased NaCl concentration or increased acidity

The effect of partial inactivation with lactic acid (LA), liquid chlorine dioxide (ClO₂) and intense light pulses (ILP) on injury and post-treatment growth under increased NaCl concentration and reduced pH values of Listeria monocytogenes strains was investigated. Inactivation levels and the percentage of sub-lethal were dependent upon strain and type of inactivation technique used. Comparison of the mean time-to-detection (TTD) values under suboptimal conditions (increased NaCl concentration or reduced pH) showed that the longest TTD was at every pH observed for the cultures treated with ClO₂, followed by LA and ILP. Under increased NaCl concentration LA treated cells required the longest TTD, followed by ClO₂ and ILP, respectively. Significant difference in TTD between untreated and cultures treated with ClO₂ and LA was observed. Recovery of ILP treated cultures was not always different from untreated cultures. The extended post-treatment effect based on the growth retardation or inhibition of injured cells under sub-optimal conditions is suggested as an important tool in conditioning of microbial food safety.Industrial relevanceSmall and medium sized enterprises (SMEs) are the backbone of the European economy. They are a key source of jobs and a breeding ground for implementation of research results. They are however the most sensitive of all to changes in the production practices coming as a consequence of increased consumers' awareness regarding fresh and natural-like foods. In order to respond to the changed consumption pattern, non-heat and so-called mild technologies have emerged. This research as a part of the EU Pathogen Combat project is tailor made to answer some of the burning issues when it comes to “mild” decontamination. Among the more established technologies used here is decontamination with lactic acid, followed by chlorine dioxide. Both are now under the eye of EU policy makers who are seeking relevant facts to adjust or not to adjust EU policy regarding decontamination of foods. Latest EFSA opinions have already pushed these agents forward, but relevant scientific facts were declared missing. Moreover, intense light pulses, as non-chemical alternative to pasteurization have a considerable potential not only in food surface decontamination, but also in the decontamination of packaging materials, industrial surfaces etc. The present research brought new facts into the light that might have a credible influence on understanding pros and cons of lactic acid, chlorine dioxide and intense light pulses as decontamination agents. The post-treatment, based on sublethal injury, effect is suggested as an important extension tool in shelf life extension and safety barrier.     

Energy consumption for heating and rebound effects

When comparing calculated heating consumption in residential buildings assuming standard usage with standardized measured data, then the two typically does not fit. In fact, measured consumption may be a fraction only of what was calculated. The reason is direct rebound behavior by the inhabitants. The paper shows the importance of direct rebound through measured results. First the temperatures, recorded in daytime and sleeping rooms in a sample of dwellings, are commented. Then follows a discussion of the indoor temperatures found when calculated energy consumptions for heating were forced to give the same numbers as measured. Next, two small scale analyses of energy data gained in low-income estates are commented, followed by test results on direct rebound in two dwellings, one non-insulated, the other well insulated. These data prove that the benefits of direct rebound are much larger in non-insulated than in well insulated homes. That fact is used to construct a rebound curve, starting from the normalized consumption data gained in 964 houses. The paper ends by showing the effect of energy price on direct rebound.     

Alternative microbial methods: An overview and selection criteria

This study provides an overview and criteria for the selection of a method, other than the reference method, for microbial analysis of foods. In a first part an overview of the general characteristics of rapid methods available, both for enumeration and detection, is given with reference to relevant bibliography. Perspectives on future development and the potential of the rapid method for routine application in food diagnostics are discussed. As various alternative “rapid” methods in different formats are available on the market, it can be very difficult for a food business operator or for a control authority to select the most appropriate method which fits its purpose. Validation of a method by a third party, according to international accepted protocol based upon ISO 16140, may increase the confidence in the performance of a method. A list of at the moment validated methods for enumeration of both utility indicators (aerobic plate count) and hygiene indicators (Enterobacteriaceae, Escherichia coli, coagulase positive Staphylococcus) as well as for detection of the four major pathogens (Salmonella spp., Listeria monocytogenes, E. coli O157 and Campylobacter spp.) is included with reference to relevant websites to check for updates. In a second part of this study, selection criteria are introduced to underpin the choice of the appropriate method(s) for a defined application. The selection criteria link the definition of the context in which the user of the method functions – and thus the prospective use of the microbial test results – with the technical information on the method and its operational requirements and sustainability. The selection criteria can help the end user of the method to obtain a systematic insight into all relevant factors to be taken into account for selection of a method for microbial analysis.     

Pulsed UV light as an intervention strategy against Listeria monocytogenes and Escherichia coli O157:H7 on the surface of a meat slicing knife

The main objective of this work was to explore the applicability of the Intense Light Pulses (ILP) for decontamination of a stainless steel meat contact surface, exemplified by a slicing knife, as a function of time between contamination and decontamination, number of light pulses applied, and the prior contact with different meat matrices. Listeria monocytogenes and Escherichia coli O157:H7 were chosen as the challenge microorganisms. The ILP system was a laboratory-scale four-lamp batch system generating 3 J/cm² with an input voltage of 3000 V. The results obtained demonstrate successful application of ILP treatment for reduction of L. monocytogenes and E. coli O157:H7 on a surface of stainless steel slicing knife. The inactivation effectiveness depended on the type of meat product that was in the contact with the treated surface and on the time between the contamination and the ILP treatment. Statistical analysis showed the significant interaction between the time and type of meat product on the effectiveness of ILP treatment. The highest effectiveness of the ILP (the complete inactivation of 6.5 log CFU/side of knife) was obtained when the knife surface was in contact with the products containing lower fat and protein content and when it was treated with pulsed light as fast as possible after the contamination (within 60 s). The decontamination efficacy of ILP treatment could not be improved by multiple light pulses if lost due to the extended time between the moment of contamination and ILP treatment. Results showed that the suggested approach can be very effective as an intervention strategy along meat processing lines preventing cross-contamination between the equipment and the final product.     

Survival of poultry-derived Campylobacter jejuni of multilocus sequence type clonal complexes 21 and 45 under freeze,chill, oxidative,acid and heat stresses

The application of multilocus sequence typing (MLST) for studying Campylobacter jejuni diversity reveals that MLST clonal complex (CC) 21 and CC-45 occupies significant proportion in the diverse population of C. jejuni. These two complexes are ecologically abundant and represent an interesting subpopulation for studying C. jejuni survival under different stress conditions. In the present study we characterize and compare 19 C. jejuni strains assigned to CC-21 and CC-45, isolated from chicken meat, based on laboratory stress models maintained in Muller-Hinton broth. Model conditions were mimicking freeze, chill, oxidative, acid and heat stresses. Results show that survival patterns varied between the strains. C. jejuni strains of CC-21 survived significantly better than C. jejuni strains of CC-45 under heat (P value = 0.022) and chill (P value = 0.001) stress models. On the other hand, C. jejuni strains of CC-45 showed significantly better survival compared to C. jejuni strains of CC-21 in response to oxidative (P value = 0.003) and freeze (P value = 0.021) stress models. C. jejuni strains assigned to the founder ST-45 showed significantly better survival (P value = 0.017) under heat stress model compared to their ancestral sequence types. However, an association between survival fitness and the diversification of a clonal group cannot be demonstrated directly from the obtained results. In conclusion, findings of the present study show that genotypic variations of C. jejuni might play a role in enabling certain lineages to be selected when encountering adverse and stressful environments. In future stress response studies, it is recommended to consider the effect of genotypic diversity among C. jejuni strains as that might bias the experimental findings.     

Influence of eggshell condensation on eggshell penetration and whole egg contamination with Salmonella enterica serovar enteritidis

Shells of agar-filled and whole eggs were inoculated with 10(3) to 10(4) CFU of Salmonella enterica serovar Enteritidis per eggshell. The agar-filled eggs were used to study bacterial eggshell penetration, and the whole egg results were used to characterize contamination of the egg contents. In each group, half of the eggs were stored for 21 days at 20 degrees C and 60% relative humidity (RH), and the other half was stored for 24 h at 6 degrees C and then for 20 days at 20 degrees C. The latter conditions resulted in condensation on the eggshell for 30 min from the moment the eggs were placed in the 20 degrees C chamber. Taking into account the ages at which hens were studied (39, 53, and 67 weeks), an average of 62% of the eggshells with condensate were penetrated compared with 43% for the control group; this difference was significant (P < 0.01). No significant difference in whole egg contamination was found; 18% of the control eggs were contaminated compared with 22% of the condensate eggs. Whole egg contamination was significantly higher for eggs from the hens at an older age (67 weeks). This difference probably was not due to a higher penetration potential because differences were not observed for the corresponding agar-filled eggs. Condensation on the eggshell seemed to encourage bacterial penetration of the eggshell but had a smaller impact on whole egg contamination.     

Illusory conjunctions die hard: A reply to Prinzmetal, Diedrichsen, and Irvy (2001).

M. Donk (see record 1999-11444-003) showed that various data patterns that have been considered as evidence for the existence of illusory conjunctions may be due to errors of target-nontarget confusion, an account that challenges the mere, existence of illusory conjunction. In a reply, W. Prinzmetal, J. Diedrichsen, and R. B. Ivry (see record 2001-06699-002) argued against this conclusion, claiming that some earlier findings can be explained only when one assumes that illusory conjunctions exist. The current article shows that Prinzmetal et al.'s claims cannot refute any of Donk's earlier conclusions, suggesting indeed that one can only conclude that "illusory conjunctions are an illusion." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Assays of CFTR Function In Vitro,Ex Vivo and In Vivo

Cystic fibrosis, a multi-organ genetic disease, is characterized by abnormal function of the cystic fibrosis transmembrane conductance regulator (CFTR) protein, a chloride channel at the apical membrane of several epithelia. In recent years, therapeutic strategies have been developed to correct the CFTR defect. To evaluate CFTR function at baseline for diagnosis, or the efficacy of CFTR-restoring therapy, reliable tests are needed to measure CFTR function, in vitro, ex vivo and in vivo. In vitro techniques either directly or indirectly measure ion fluxes; direct measurement of ion fluxes and quenching of fluorescence in cell-based assays, change in transmembrane voltage or current in patch clamp or Ussing chamber, swelling of CFTR-containing organoids by secondary water influx upon CFTR activation. Several cell or tissue types can be used. Ex vivo and in vivo assays similarly evaluate current (intestinal current measurement) and membrane potential differences (nasal potential difference), on tissues from individual patients. In the sweat test, the most frequently used in vivo evaluation of CFTR function, chloride concentration or stimulated sweat rate can be directly measured. Here, we will describe the currently available bio-assays for quantitative evaluation of CFTR function, their indications, advantages and disadvantages, and correlation with clinical outcome measures.