Search

A quantitative risk assessment model of yogurt spoilage by Aspergillus niger was developed based on a stochastic modeling approach for mycelium growth by taking into account the important sources of variability such as time-temperature conditions during the different stages of chill chain and individual spore behavior. Input parameters were fitted to the appropriate distributions and A. niger colony’s diameter at each stage of the chill chain was estimated using Monte Carlo simulation. By combining the output of the growth model with the fungus prevalence, that can be estimated by the industry using challenge tests, the risk of spoilage translated to number of yogurt cups in which a visible mycelium of A. niger is being formed at the time of consumption was assessed. The risk assessment output showed that for a batch of 100,000 cups in which the percentage of contaminated cups with A . niger was 1% the predicted numbers (median (5 th , 95 th percentiles)) of the cups with a visible mycelium at consumption time were 8 (5, 14). For higher percentages of 3, 5 and 10 the predicted numbers (median (5 th , 95 th percentiles)) of the spoiled cups at consumption time were estimated to be 24 (16, 35), 39 (29, 52) and 80 (64, 94), respectively. The developed model can lead to a more effective risk-based quality management of yogurt and support the decision making in yogurt production.

A bronchial allergen challenge may serve both as a diagnostic as well as investigative procedure. Its usage in the diagnosis of asthma is infrequent due to its time-consuming nature as well as (in our opinion) an unfounded fear for a patient's safety. It is quite useful in the diagnostics of workplace related illnesses. Due to its ability to produce a controlled, long-lasting allergic-inflammatory reaction in the bronchi, this procedure is commonly used in research settings as well as in the assessment of new substances which may potentially have a place in the treatment of asthma, for ex. through the blocking of late asthmatic reactions. Changes stimulated by a bronchial allergen challenge may be evaluated by many methods using different materials, i.e. samples obtained from direct biopsies, bronchoalveolar lavages, exhaled breath condensates, or measured fractional exhaled nitric oxide. This procedure is a seemingly ideal research and diagnostic tool, however, a common protocol for its execution has not yet been accepted. Recent legal regulations have resulted in difficulties obtaining various allergens for challenge tests. Hopefully this is a temporary and minor setback for this very useful and constantly developing procedure.

Introduction and objectives Occupational causes are thought to account for 20% of the global burden of asthma. The gold standard test for identifying occupational asthma (OA) is specific inhalational challenge to the suspected occupational agent.1 However, a negative SIC does not always exclude a diagnosis of OA. We investigated the reasons why challenge tests may be negative and associated outcomes from two UK centres. Methods We performed a retrospective review of the outcomes of 79 consecutive negative SICs carried out between 2008 and 2019 in North Manchester General Hospital (NMGH) and Birmingham Heartlands Hospital (BHH). Repeat negative SICs for the same patient were also included. Demographic data, serial peak flow analysis, occupation, current exposures, and progress post SIC were reviewed. Patients were followed up post SIC and further testing (either repeat SIC or other) were performed if ongoing symptoms were present. Results Of the79 negative SICs reviewed, 23 were at NMGH and 56 at BHH. Thirty-six workers (45%) were female, median age 51 years (IQR 41–55.5). Ten workers (13%) had a history of previous asthma. Sixty five percent of SICs had an OASYS score of ≥2.51 i.e. positive for work effect prior to testing. Of the 79 SICs carried out, 50 were subsequently diagnosed with occupational asthma with diagnostic serial PEF records and/or repeat testing. The most common reason for a negative SIC was testing to the wrong agent (figure 1). Conclusions This data suggests that there is a high rate of negative SICs in patients who have a diagnosis of occupational asthma, which is mainly due to exposures to the wrong agent in the SIC. It is crucial that patients are followed up post negative SIC and re investigated early if experiencing ongoing symptoms. Reference Specific inhalation challenge in the diagnosis of occupational asthma: consensus statemen Vandenplas O. et al. European Respiratory Journal 2014 43: 1573–1587.

The aim of this study was to quantify the influence of temperature on pH min -values of Listeria monocytogenes as used in cardinal parameter growth models and thereby improve the prediction of growth for this pathogen in food with low pH. Experimental data for L. monocytogenes growth in broth at different pH-values and at different constant temperatures were generated and used to determined pH min -values. Additionally, pH min -values for L. monocytogenes available from literature were collected. A new pH min -function was developed to describe the effect of temperatures on pH min -values obtained experimentally and from literature data. A growth and growth boundary model was developed by substituting the constant pH min -value present in the Mejlholm and Dalgaard (2009) model (J. Food. Prot. 72, 2132-2143) by the new pH min -function. To obtain data for low pH food, challenge tests were performed with L. monocytogenes in commercial and laboratory-produced chemically acidified cheese including glucono-delta-lactone (GDL) and in commercial cream cheese. Furthermore, literature data for growth of L. monocytogenes in products with or without GDL were collected. Evaluation of the new and expanded model by comparison of observed and predicted μ max -values resulted in a bias factor of 1.01 and an accuracy factor of 1.48 for a total of 1,129 growth responses from challenge tests and literature data. Growth and no-growth responses of L. monocytogenes in seafood, meat, non-fermented dairy products, and fermented cream cheese were 90.3% correctly predicted with incorrect predictions being 5.3% fail-safe and 4.4% fail-dangerous. The new pH min -function markedly extended the range of applicability of the Mejlholm and Dalgaard (2009) model from pH 5.4 to pH 4.6 and therefore the model can now support product development, reformulation or risk assessment of food with low pH including chemically acidified cheese and cream cheese.

In the present work, a combined hurdle approach for fermented meat preservation was investigated. Challenge tests were performed in Chorizo sausage model using the maximum allowed NaNO2 amount (150 mg/kg), a reduced amount (75 mg/kg) and no nitrite, with and without protective cultures inoculation. Cocktail strains of L. monocytogenes and Salmonella spp. were used as indicator strains. In a nitrite reduced sausage model, L. monocytogenes growing trend did not significantly change (p > 0.05) when compared with that containing higher nitrite concentration (150 mg/kg NaNO2). The addition of L. plantarum PSC20 significantly lowered L. monocytogenes growth when compared with control batches without PCS20 (p < 0.05), obtaining 3.84 log cfu/g and 2.62 log cfu/g lower counts in the batches with 150 mg/kg NaNO2 and 75 mg/kg NaNO2 respectively. None of the protective cultures demonstrated in situ antagonistic activity against Salmonella spp. This work pointed out that the reduction of nitrites with the combined use of a protective culture could be a feasible approach to control L. monocytogenes growth in fermented meat foods.

This study involved ten enterprises producing Italian salami, 20 different samples of fermented sausages underwent challenge tests to assess and record the following parameters: time, temperature, pH, aw, and Salmonella counts. A linear regression model was used to describe the Salmonella spp. decay: at the end of the process the result of total Salmonella reduction was 0.97–5.84 Log10 CFU/g and it was significantly associated with pH at the end of acidification/drying process, aw at the end of seasoning period, the duration of seasoning, and the caliber of salami respectively. High Pressure Processing (HPP) further reduced the Salmonella level by 2.41–5.84 Log10 CFU/g with an efficacy that resulted inversely associated with aw of salami at the end of seasoning; the objective of 5-Log reduction was always reached in all the cases tested by the production process plus HPP. This model could be a useful tool for enterprises and Authorities to evaluate the efficacy of the processes to reduce Salmonella load for exportation to the U.S.

Metabolic challenge tests may be a valuable tool to magnify the effects of diet on health. The use of transcriptomics enables a more extensive characterization of the effects of diet. The question remains whether transcriptome time-course analyses during challenge tests will deliver more information on the effect of diet than a static fasting measurement. A dietary intervention known to improve health is energy restriction (ER). Seventy-two healthy, overweight men and women aged 50-65 were subjected to an oral glucose tolerance test (OGTT) and a mixed-meal test (MMT) before and after 12 wk of a 20% ER diet or control diet. Whole-genome gene expression of peripheral blood mononuclear cells was performed before and after the intervention. This was done during fasting, during the OGTT at 30, 60, and 120 min, and during the MMT at 60, 120, 240, and 360 min. Upon ER, the OGTT resulted in a faster and more pronounced down-regulation in gene expression of oxidative phosphorylation, cell adhesion, and DNA replication compared with the control. The MMT showed less-consistent effects. The OGTT combined with transcriptomics can be used to measure dynamic cellular adaptation upon an intervention that cannot be determined with a static fasting measurement.-Van Bussel, I. P. G., Fazelzadeh, P., Frost, G. S., Rundle, M., Afman, L. A. Measuring phenotypic flexibility by transcriptome time-course analyses during challenge tests before and after energy restriction.

Fermented foods are extremely popular nowadays mainly thanks to their health benefits and diversity. One example of a fermented food is miso, a fermented soybean paste very famous in Japan, also considered a functional food and used to make soups or as a seasoning for several dishes. In Japan, miso is made by traditional backslope methods. With the arrival of miso to West-ern countries, more standard, controlled, sustainable and safe processes are needed, starting by switching the soybean by Portuguese legumes (e.g. grass pea) and by developing starters. The aim of this project is to develop an innovative, tastier and safe grass pea miso, using a yeast starter culture and soybean miso as control. The characteristics and evolution of miso were evaluated, based on color and microbiota studies. Results obtained point to an important role of Aspergillus oryzae at the beginning of fer-mentation, and to the maintenance of the viability of yeasts (Candida versatilis) used as a starter along the whole process of miso’s maturation. Also, the obtained product presented good senso-rial characteristics being largely accepted by consumers. The self-preservation capacity of grass pea miso was also evaluated in order to ensure that the product is safe when stored at the consumer’s house and shop shelves. Using challenge tests at several temperatures (4ºC, 25ºC and 37ºC), it was observed a substantial reduction in the pathogenic microorganisms’ population, in most cases leading to its complete elimination. At the temperatures of 37ºC and 25ºC, all the microorganisms were eliminated (except for Bacillus cereus) after 2 days while at 4ºC it takes more than 30 days for them to be eliminated.

Background Specific challenge tests (SIC) are regarded as the reference standard in the diagnosis of occupational asthma. As part of an audit of specific inhalation testing 2006–2015 we have identified 12 workers whose SIC were negative but for which there was strong alternative evidence of occupational asthma. We have looked for causes for the discordance. Methods We performed SIC in 125/343 workers with possible occupational asthma with latency referred to us from 2006–2015. In 72 the SIC was negative, 12 of these had serial PEF evidence of occupational asthma with positive scores from the Oasys computer assisted diagnostic program both for the Area-Between Curves (ABC)>15 litres/min/hour and discriminant analysis (Oasys score)>2.5 (combined specificity 100%, sensitivity 60% with positive SIC as positive referent and non-exposed asthmatics as negative referent), and both scores becoming negative after relocation with the same employer. It is likely that at least these 12 had falsely negative SICs. We have investigated why the SICs may have been negative following a subjective review of all data. Results The mean ABC score was 30.3 l/min/hour (range 60.8–19.1) pre-relocation and −12.1 l/min/hour (range −48.6 -+9.9) post-relocation. The Oasys discriminant scores were 3.52 (4–2.67) pre-relocation and 1.73 (2.29–1.13) post-relocation. The cause was likely to be an agent not tested in SIC despite testing 4–8 agents each in 7 workers. Likely missed causes included a mouldy school building (figure 1), environmental welding fume, cleaning materials and a lack of protein source for chlorine-releasing agents. In 2 there was no exposure to the likely cause for >6 months, in 3 the control days were too unstable to identify late reactions, perhaps related to LABA withdrawal pre-challenge, and in 3 the work-exposures were likely to be much higher than used in the SIC (MDI, shrink-wrap and plastic moulding) (>1 reason possible). 9 were taking ICS during SIC which may have limited reactions. Conclusion Occupational asthma is still possible despite negative SIC. The figure shows the mean hourly PEF on days at home and days at work in a DT technician before (top) and after (bottom) relocating to new buildings with the same work exposures.

Liposomes are targeted drug delivery systems that are of great pharmaceutical and therapeutic interest. Parenteral route is the main way used for liposome administration. In this case, their sterility is a requirement. However, due to the particular sensitivity of liposomes and their tendency to physicochemical alterations, their sterilization remains a real challenge. Conventional sterilization methods such as heat, ethylene oxide, ultraviolet and gamma irradiations are considered as unsuitable for liposome sterilization and the recommended methods for obtaining sterility of liposomes are filtration and aseptic manufacturing. Unfortunately, these recommended methods are not without limitations. This review outlines the difficulties associated with the use of these different classical methods for obtaining liposome sterility. The effects on liposome physicochemical and biopharmaceutical characteristics as well as efficacy, toxicity and practical problems of these sterilization techniques have been discussed. The search for an alternative method being therefore necessary, the applicability of supercritical carbon dioxide (ScCO2) technology, which is nowadays a promising strategy for the sterilization of sensitive products such as liposomes, is also examined. It appears from this analysis that ScCO2 could effectively be an interesting alternative to achieve sterility of liposomes, but for this, sterilization assays including challenge tests and optimization studies are needed.

A model describing Listeria innocua evolution according to process parameters of 51 Italian salami processes and HPP in 31 companies was developed. A total of 51 challenge tests were performed. During processing a L. innocua reduction of 0.34–4.32 Log10 CFU/g was observed and HPP further reduced the count of 0.48–3.47 Log10 CFU/g; an overall reduction of 1.04–5.68 is reached. PH after acidification/drying process, aw after seasoning, duration of the seasoning and caliber resulted associated (p < 0.05) with L. innocua decrease. HPP efficacy was associated (p < 0.05) with aw and pH of the product: higher the pH and aw after the acidification/drying and seasoning phases, higher resulted the L. innocua reduction after HPP. No significant association was observed between L. innocua and salt, nitrate and starter content and other characteristics of process. The model meets companies and Authorities needs and represents a useful tool to predict L. monocytogenes lethality, giving recommendations to food business operators interested in exportation to the U.S.

Cheese potentially allowing the growth of Listeria monocytogenes must be free of the pathogen in 25 g before being put on the market, while 100 cfu/g is tolerated when the pathogen is unable to grow. Challenge tests were performed in order to assess the growth potential of L. monocytogenes in at least one batch of 32 Belgian cheese varieties from 32 factories. All varieties were grouped in four categories: unripened acid-curd cheeses, mold-ripened soft cheeses, smear-ripened soft cheeses and ripened semi-hard cheeses. Associated microflora and cheese physicochemical characteristics were also studied. A cocktail of three strains was used to inoculate cheese on the first day of shelf-life, and samples were stored until the end of shelf-life at 7–9 °C. Growth potential was considered as the difference (a) between median contamination at the end and at the beginning of the test or (b) between the highest value at the end of the test and the lowest value at its beginning. L. monocytogenes always decreased in unripened acid-curd cheeses but showed extended growth in 21 out of 25 batches of ripened soft cheese. Contrasting results were obtained for semi-hard cheeses, as important intra- and inter-batch variability was observed. For the latter, the recommended method based on medians to calculate the growth potential led to erroneous food safety considerations, and it should always be advised to focus on absolute levels.

Optical rhinometry is the only diagnostic tool in rhinitis for assessing real-time changes in nasal occlusion. It illustrates lumen changes of nasal mucosa vessels in response nonspecific/specific factors and not only. The first attempts to standardize the method conducted by German researchers show the potential of optical rhinometry not only as regards challenge tests, but also vice versa, in respect of the anemization of the mucosa it evaluates the extent of the oedema which occurred in the pathomechanism of non-allergic rhinitis. The relatively small number of publications in the domain of interest demonstrates there is a need to conduct further research on the suitability of the above-mentioned technique for the evaluation of nasal patency in the field of rhinological diagnostics.

This study investigated whether individual behavioural characteristics of piglets and stress induced by experience with humans can influence learning performance. After weaning, piglets received a chronic experience with humans to modulate their emotional state: rough (ROU), gentle (GEN), or minimal (MIN) experience. Simultaneously, they were trained on a discrimination task. Afterward, their behaviour during challenge tests was assessed. The first learning step of the task involved associating a positive sound cue with a response (approach a trough) and success of piglets depended mostly on motivation to seek for reward. Although the experience with humans did not have direct effect, the degree of fear of handler, measured based on their reactivity to a human approach test, was related to motivation to seek rewards and learning speed of this first step in stressed ROU piglets, but not in MIN and GEN piglets. In contrast, the second learning step was more cognitively challenging, since it involved discrimination learning, including negative cues during which piglets had to learn to avoid the trough. Locomotion activity, measured during an open-field test, was associated with performance of the discrimination learning. To conclude, fearfulness towards humans and locomotion activity are linked with learning performance in relation to task complexity, highlighting the necessity to take into account these factors in animal research and management.

International audience; Ruminants are healthy carriers of Shiga toxin producing Escherichia, coli (STEC). If good hygienic and agricultural practices at the farm level, especially during the milking process, are not adequately followed, milk and dairy products made with raw milk could become contaminated. Sporadic cases and rare food outbreaks have been linked with dairy products. Consequently, understanding STEC behavior in cheeses would help to evaluate risks for human health. The behavior of 4 different STEC strains belonging to the serotypes O26:H11, O103:H2, O145:H28, and O157:H7 were monitored during the manufacture, ripening, and storage of a white mold soft cheese. These strains, originating from dairy products, were inoculated individually in raw milk from cow at 102 cfu/mL. During the first 24 to 30 h of the manufacturing stage, the STEC level increased by 2 to 3 log(10) cfu/g. Over the course of the ripening stage, the concentration of the non-O157 STEC remained relatively constant, whereas a decrease of the E. coli, O157:H7 concentration was observed. During the storage stage, the level of the different non O157 STEC strains decreased slowly in the core and in the rind of cheeses. The non-O157 STEC level reached between 3.1 and 4.1 log(10) cfu/g at d 56. Interestingly, the concentration of the E. coli O157:H7 strain decreased dramatically: the strains remained detectable only after enrichment. During ripening and storage, STEC levels were generally higher in rinds than in cheese cores. In contrast to what was seen in cheese cores, the E. coli O157:H7 strain remained enumerable in rinds during these steps. These results highlight that STEC can grow during the manufacture and survive during the ripening and storage of a white mold soft cheese.

Despite satisfactory reactions to seawater challenge tests indicative of appropriate physiological state, hatchery-reared Atlantic salmon Salmo salar smolts stocked in the Eira River in Norway between 2001 and 2011 performed less well at sea in terms of growth, age at maturity and survival than smolts of natural origin. The mean rates of return to the river for hatchery-reared and naturally produced S. salar were 0·98 and 2·35%. In the Eira River, c. 50 000 hatchery-reared S. salar smolts of local origin were stocked annually to compensate for reduced natural smolt production following regulation for hydroelectric purposes, while a mean of 17 262 smolts were produced naturally in the river. This study demonstrates that, although captive S. salar perform well in seawater challenge tests, hatchery-reared smolts are not necessarily as adaptable to marine life as their naturally produced counterparts. These findings suggest that production of hatchery-reared smolts more similar to naturally produced individuals in morphology, physiology and behaviour will be necessary to improve success of hatchery releases. Where possible, supplementary or alternative measures, including habitat restoration, could be implemented to ensure the long-term viability of wild stocks.

Background As post-consumer recycled plastics may be contaminated with chemical substances, their use for food packaging may raise food safety issues. Recycling technologies should therefore efficiently remove contaminants of concern. Scope and approach Usually, the abundant data available for recycled poly(ethylene terephthalate) (PET) are extrapolated to polyolefins. This paper reviews the differences of basic properties and typical contaminants of polyolefins compared to PET. The use of thermal desorption process to remove polyolefin contaminants is discussed. Key findings and conclusions It is suggested in this review that this extrapolation is not scientifically justified, on the basis of the comparison between the intrinsic diffusion properties of contaminants of concern in PET and in polyolefins. It is concluded that the scope of contaminants of concern considered for the safety assessment of polyolefins recycling technologies based on thermal desorption should be carefully re-examined.

Stormwater harvesting biofilters need to be validated if the treatment is to be relied upon. Currently, full-scale challenge tests (FCTs), performed in the field, are required for their validation. This is impractical for stormwater biofilters because of their size and flow capacity. Hence, for these natural treatment systems, new tools are required as alternatives to FCT. This study describes a novel in-situ method that consists of a thin stainless steel column which can be inserted into constructed biofilters in a non-destructive manner. The in-situ columns (ISCs) were tested using a controlled field-scale biofilter where FCT is possible. Fluorescein was initially used for testing through a series of continuous applications. The results from the ISC were compared to FCT conducted under similar operational conditions. Excellent agreement was obtained for the series of continuous fluorescein experiments, demonstrating that the ISC was able to reproduce FCT results even after extended drying periods (Nash-Sutcliffe coefficient between the two data sets was 0.83-0.88), with similar plateaus, flush peaks, slopes and treatment capacities. The ISCs were then tested for three herbicides: atrazine, simazine and prometryn. While the ISC herbicide data and the FCT data typically matched well, some differences observed were linked to the different climatic conditions during the ISC (winter) and FCT tests (summer). The work showed that ISC is a promising tool to study the field performance of biofilters and could be a potential alternative to full scale challenge tests for validation of stormwater biofilters when taking into account the same inherent boundary conditions.

Raw minimally processed vegetables and fruits as well as boiled pasta and potato are the main ingredients of ready-to-eat (RTE) salads. These ingredients are diverse in their ability to support growth of Listeria monocytogenes . The objective of this study was to determine to what extent different ingredients can contribute to growth of L. monocytogenes in RTE salads. This was done by assessing the growth capacity of L. monocytogenes in ingredients of RTE salads by means of challenge tests and determination of the effect of product characteristics and presence of competitive flora. The majority of the tested products did not support or hardly supported growth of L. monocytogenes . The calculated maximum increase of 3.4 log CFU/g was exceeded in Galia melon, potato and pasta products. In RTE dinner salads, growth of L. monocytogenes was supported by the carbohydrate component. Galia melon, which is often used as ingredient of fruit salads, can contribute to growth of L. monocytogenes in these products. Growth inhibition, or differences in relative increase, could not always be explained by a w , pH or presence of competitive flora. The effect of competitive flora, especially lactic acid bacteria, on growth inhibition was observed in non-pasteurized potato, white cabbage and mango.

Background Soybeans are one of causative foods for infantile onset allergies in Japan. This study aimed to analyze the results of soybean challenge tests that were conducted over approximately 7 years at our institution. Using the test data, we sought to identify the responses and clinical profiles of patients with soybean allergies, and to investigate the relationship between the responses and soybean sensitization status. Methods Between July 2004 and May 2010, 142 cases (125 patients) underwent food challenge tests (100 g of silken tofu) for the diagnosis of soybean allergy or confirmation of their tolerance. The patients' characteristics, soybean sensitization status, and responses to the challenge tests were retrospectively evaluated. Results Among the subjects who underwent the soybean challenge test, the male/female ratio was 1.6 (87/55), and the mean age at the test was 2.8 ± 1.7 years. The positive rate for the challenge test was 38.7%. Induced symptoms were observed in the skin (81.8%), respiratory system (50.9%), and gastrointestinal system/mucosal membrane/anaphylaxis (12.7%). Intramuscular epinephrine was administered to all 7 patients who experienced an anaphylactic reaction. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic efficiency of soybean-specific IgE titers were low for predicting the responses to the challenge test. Conclusions Soybean allergies were diagnosed in only 18% of the subjects with positive sensitization to soybeans. Therefore, soybean-specific IgE titers are not an effective predictor of a positive response to the challenge test.

Passive gravity-driven membrane (PGM) filtration is a type of gravity-driven membrane (GDM) filtration operated with passive physical fouling control measures that add limited to no complexity to the system (e.g. permeate flux interruptions, gravity-driven air scouring, system draining), allowing a greater permeate flux to be sustained. A key aspect of PGM/GDM systems is the development of a structurally loose and permeable biofilm layer on the membrane that enables a sustainable flux to be achieved and has also been associated with improved removal of humic acids, polysaccharides, proteins, assimilable organic carbon and microcystins. The present study investigated if the biofilm layer of PGM systems also contributes to virus removal, for both intact and breached PGM systems. Breach sizes considered ranged from 20 to 180 µm. Challenge tests (CTs) identified an increase of 2.0+ in the log removal value (LRV) for viruses in both intact and breached PGM systems when a biofilm layer was present, suggesting that the biofilm layer is capable of bridging the gap over integrity breaches, acting as a secondary barrier to contaminants that would otherwise bypass treatment by flowing through the breach. Pressure decay tests (PDTs), however, did not identify the same increase in LRVs as that of CTs, suggesting that the standard PDT approach cannot consider the contribution of the biofilm layer to the removal of small material such as viruses. An alternative integrity testing protocol for PGM systems was developed using a modified PDT approach that takes into account the additional removal provided by the biofilm layer. This alternative protocol is also simpler and requires less frequent testing, contributing to the simplification of overall operation of PGM systems in small/remote communities and decentralized applications.

The evaluation of the microbiological shelf-life under refrigeration conditions of steak tartare showed Total Viable Counts (excluding LAB) around 4 Log CFU/g at the beginning of the study, with a gradual increase reaching 7 Log CFU/g after 12 days. LAB represented the main microflora. A significant acidification was detected at the end of the shelf life. Total Volatile Basic Nitrogen concentration changed slightly during the shelf life. After an initial increase (until T5), all the colour indices were stable. The growth potential of Listeria monocytogenes was also evaluated in accordance with EURL Lm guidelines by conducting challenge tests. The growth potential calculated during the challenge test performed on three different batches indicated the absence of a significant growth (δ

Previously, immediate reactions to ionic high-osmolar iodinated contrast media (ICM) were regarded as nonimmunological. How ever, despite the use of lower-osmolar ICM, ICM hypersensitivity still occurs in some patients and recent studies suggest that there would be a true allergic response, especially in more severe form. Currently, it is important to identify the sensitized ICM and avoid the agent; however, the usefulness of skin tests and challenge tests has not yet been established, since there are few large-scale studies on them. Although, skin test-negative ICM can be safely used in clinical practice, conflicting results have been reported through various studies, depending on the challenge protocols used. Therefore, standard protocols need to provided. Even if a cul prit agent is not proven by skin tests, its use should be avoided. Reuse of contrast media increases the risk of occurrence of hyper sensitivity reactions. For patients with previous hypersensitivity reactions to contrast media, premedication can help prevent recur rence, but breakthrough in hypersensitivity is not fully achieved by premedication, especially when the previous reaction was a se vere form such as anaphylaxis. Therefore, it is necessary to establish an optimal strategy to choose alternative ICM and premedica tion protocols to prevent recurrence of hypersensitivity reactions to nonionic contrast media. (Allergy Asthma Respir Dis 2020;8:107-113)

Honey is a food ingested worldwide. Allergic reaction to honey is rare and only a few cases have been reported in the literature. A 20-month-old boy developed angioedema 30 minutes after eating rice cake containing honey. After 2 weeks, we performed food challenge tests with honey which resulted in anaphylaxis. This is the first case report on anaphylaxis to honey in Korea. (Allergy Asthma Respir Dis 2020;8:147-149)