Growth or penetration of Salmonella into citrus fruit is not facilitated by natural-light labels

In natural-light labeling of fruits and vegetables, the desired information is etched onto the produce surface using a low-energy carbon dioxide laser beam (10,600 nm). Etched characters are formed by surface depressions in the epidermis that may facilitate entrance of decay and pathogenic organisms. The objective of this study was to determine the effects of natural-light labeling and different postharvest treatments on Salmonella populations' ability to survive/grow and penetrate into citrus fruit. A five-strain cocktail of Salmonella was spot inoculated onto Valencia orange in different application sequences with wax and natural-light etching. Samples were stored at 10, 26 °C, or combinations of both, for up to 42 days. Etched peels and corresponding juices were extracted from whole oranges following storage and enumerated for Salmonella. No set of conditions involving natural-light labeling promoted the growth of Salmonella on the fruit surface or resulted in the detection of Salmonella from the juice of sound fruit. Survival of Salmonella populations on the peel surface did not differ between any of the treatment and control samples. In all cases, Salmonella declined between 1.5 and 3.0 log CFU/orange after 30 days, with faster decline noted at 10 °C. Based on the data obtained from all treatments and under conditions extremely unfavorable and unrealistic in terms of fruit storage, natural-light labeling citrus fruit peels and subsequent waxing in any order did not allow for the growth or influence the natural decline of Salmonella populations on citrus fruit surfaces, or movement into juices, as compared to controls.     

Screening and identification of a Bacillus amyloliquefaciens strain for aqueous enzymatic extraction of medium-chain triglycerides

A strain with a high yield of neutral proteinase and low yield of lipase, resistance to medium chain fatty acid triglycerides is the key to increasing yield and quality of Cinnamomum camphora seed kernel oil (CCSKO) with aqueous enzymatic extraction technology. A bacterial strain, NCU116 isolated from the waste residue produced in CCSKO production through primary screening with plate and secondary screening with shake-flask fermentation. It was found to be suitable for the extraction of CCSKO or other medium-chain triglycerides by using the extraction technology. Its activity of neutral proteinase was 4536.5 U/mL, and only 0.088 U/mL for lipase production. The strain was identified as Bacillus amyloliquefaciens by morphological, physiological, biochemical and 16S rDNA molecular identification. The extracellular enzymes produced by NCU116 included neutral proteinase, pectinase, glucoamylase, cellulase, amylase and lipase. The neutral proteinase had the maximum activity at 50 °C, but was unstable. Its optimum temperature and pH value were approximately 40 °C and 7.0 respectively. Mn²⁺ was an activator of neutral proteinase. The glucoamylase had the maximum activity at 45 °C, and was activated by Ca²⁺, Zn²⁺, Fe³⁺ and Mn²⁺. Its optimum temperatures and pH value were 45–50 °C and 6.0 respectively. The pectinase had the maximum activity at 40 °C, and was activated by Cu²⁺, Fe²⁺, Mn²⁺ and Ca²⁺. Its optimum temperatures and pH value were 35–40 °C and 7.0 respectively. The cellulase had the maximum activity at 35 °C, and was activated by Ca²⁺ and Mn²⁺. Its optimum temperatures and pH value were 30–40 °C and 7.0 respectively.     

Antimicrobial activities of red wine-based formulations containing plant extracts against Escherichia coli O157:H7 and Salmonella enterica serovar Hadar

We evaluated the antimicrobial activities of three red wine based plant extract/plant essential oil (EO) formulations: olive extract powder/oregano EO, apple skin extract powder/lemongrass EO, and green tea extract powder/bitter almond EO, and their formula permutations against the foodborne pathogens Escherichia coli O157:H7 and Salmonella enterica serovar Hadar. The following parameters that were expected to affect antimicrobial activity were evaluated: pH (3.6 or 7.0), temperature (4, 22, and 37 °C), incubation time (0, 5, 30, and 60 min) and bacterial load (∼10⁴ or ∼10⁹ bacteria/ml). The formulations with oregano, lemongrass, or bitter almond EO inhibited the growth of both pathogens at acidic pH with bacterial loads of ∼10⁴ or ∼10⁹ bacteria/ml. At neutral pH, the formulations were less effective. Although all the 3-component formulations were fast acting; showing significant activity in less than 5 min, only the activity of the lemongrass-containing formulation markedly increased with longer incubation times from 0 to 60 min. Activity also increased for all 3-component formulations with increasing temperature from 4 °C to 37 °C, although the activity of the lemongrass formulation appeared to level off at 22 °C. Of the tested formulations, the lemongrass EO formulations, at pH 3.6, appeared to be the most effective against the tested pathogens, especially against Salmonella. The most active formulations merit evaluation for antimicrobial efficacy in liquid and solid food.     

Thermal treatments and their effects on the fumonisin B1 level in rice

The objective of this study was to evaluate the effects of dry and hydrothermal treatment on FB₁ level in polished, parboiled and whole grain rice collected in Brazilian market. The effect of thermal treatment on FB₁ level was carry out by applying conventional cooking, autoclaving and dry heat treatment. Conventional hydrothermal treatment (cooking) reduced the initial natural contamination by 80%. However, no significant reduction was obtained by autoclaving. Dry heat treatment produced the reduction (70%), at temperatures range from 150 to 200 °C.     

Potential use of carvacrol and citral to inactivate biofilm cells and eliminate biofouling

Biofouling (i.e., accumulation of microorganisms on wetted surfaces) represents a major problem in the food industries, since bacterial biofilms are common sources of persistent infections due to their resilience to cleaning and disinfection treatments. Therefore, alternative treatments based on the use of essential oils or their individual compounds against this bacterial adaptation phenomenon are currently being studied. This work presents a quantitative comparison of the disinfectant potential of 500–2000 μL/L of carvacrol or citral against mature biofilms of Staphylococcus aureus SC-01, Listeria monocytogenes EGD-e or Escherichia coli MG1655. Treatments with 1000 ppm of carvacrol or citral at 45 °C for 60 min were capable of reducing more than 5 logarithmic cycles of the sessile cells forming part of mature biofilms of all the three species. Furthermore, the synergism observed between carvacrol and heat allowed for the physical removal of biofilms by treatments simulating in situ wash conditions (80 °C/60 s). These results demonstrate the great potential of the essential oils’ constituents citral and carvacrol in the eradication of biofilms formed by foodborne pathogenic microorganisms.     

Highly enhanced bactericidal effects of medium chain fatty acids (caprylic,capric, and lauric acid) combined with edible plant essential oils (carvacrol,eugenol, β-resorcylic acid,trans-cinnamaldehyde,thymol, and vanillin) against Escherichia coli O157:H7

Medium chain fatty acids (MCFAs) and essential oils (EOs) are known to be natural antimicrobials, but their combined effects have not been fully investigated. The objective of the present study was to examine the bactericidal effects of various combined treatments of MCFAs [caprylic (CA), capric (CPA), and lauric acid (LRA)] and EOs [carvacrol (CAR), eugenol (EUG), β-resorcylic acid (RA), trans-cinnamaldehyde (TC), thymol (TM), and vanillin (VNL)]. Escherichia coli O157:H7, was treated with 1) control (2% ethanol), 2) MCFA alone, 3) EO alone, and 4) different combinations of MCFAs and EOs at 37 °C for 5 and 10 min. Synergistic bactericidal effects were observed with combined treatments; the log reduction in viable bacteria in response to the combined treatments was much greater than the sum of the effects of the two compounds applied individually. For example, individual treatment with 0.2 mM CPA (0.004%) and 0.4 mM RA (0.006%) for 5 min resulted in a negligible reduction in bacterial load (0.25 and 0.21 log reduction, respectively), whereas combined treatment at the same concentrations and for the same time reduced the bacterial population in the test sample to an undetectable level (initial population: 7.51 log CFU/ml; detection limit: 1 CFU/ml). The ranking of EOs showing the highest bacterial killing activities when combined with MCFAs was generally RA, CAR, TM > EUG > TC > VNL. All the antimicrobials used in this study are natural compounds that have been widely used in industry, so they are both consumer- and user-friendly. Combined treatment can overcome the disadvantages of MCFAs and EOs such as unpleasant odor and high cost because the required concentrations can be reduced. Our results indicate that the combined treatments used here could be successfully used to eliminate foodborne pathogens, significantly improving the microbiological safety of foods.     

Development of an aptasensor for the fast detection of Versicolorin A

Aflatoxins (AFs) are secondary metabolites produced by Aspergillus flavus and Aspergillus parasiticus. The molds may contribute to pre-harvest aflatoxin contamination of susceptible crops. For the customer and food producer, a predictive model for aflatoxin detection is very desirable. Versicolorin A (VerA), which is the first precursor in the pathway of aflatoxin B₁ (AFB₁) biosynthesis, shares similar toxic group with the furofuran structure in aflatoxin B₁. VerA exhibits a much lower teratogenic toxicity than AFB₁ and may be used as a predictive indicator for aflatoxin B₁ contamination of storage crops. Therefore, the development of a fast detection method for VerA is important. One of the randomly computer-generated aptamers of VerA was confirmed by isothermal titration calorimetry with K_d = 9.26 × 10⁻⁶ mol l⁻¹. In addition, a simple and sensitive label-free aptasensor was developed for the electrochemical detection of VerA. According to the results from differential pulse voltammetry (DPV), a linear relationship existed between the log conc. of VerA (ranged from 0.01 to 100 ng ml⁻¹) and the current (△I_p) with a limit of detection (LOD) of 10 pg ml⁻¹. The resulting aptasensor exhibited good reproducibility for detecting VerA and stability after storage for 15 days at 4 °C with acceptable anti-interference against ZEN, OTA, DON, and FB₁. When used in corn samples, the recoveries of VerA were determined to be in the range of 81.3%–104.4 %. Although with some intercross, result suggests that the obtained aptamer for VerA is potentially used as a sorbent for the preparation of solid-phase-extraction procedure to clean up food samples in conjunction with high-performance liquid chromatography analysis.     

Geobacillus stearothermophilus ATCC 7953 spore chemical germination mechanisms in model systems

Bacterial endospores through their strong resistance to both chemical and physical hurdles constitute a risk for food industry. Inactivation strategies are based on thermal and/or chemical treatments but rely on incomplete knowledge of the mechanisms of inactivation. Alternative strategies were suggested to achieve food safety while improving product quality. One of them relies on the successive germination and inactivation by pasteurization of bacterial spores. However, to date, a gap of knowledge on bacterial spore germination remains and hinders such an application for food sterilization. Geobacillus stearothermophilus ATCC 7953 spore germination mechanisms were investigated by in situ fluorometry combined with plate counts. G. stearothermophilus spores' inner membrane was stained with Laurdan fluorescent dye. While nutrient pathways showed no strong germination with the combinations tested, successful germination up to 3 log₁₀ could be achieved using 60 mmol l⁻¹ calcium-dipicolinic acid (CaDPA) at 55 °C for 2 h. A model for the CaDPA germination mechanism in two phases could be derived which suggested a potential key role of cortex fragments in the germination path, before completion of the cortex degradation. Additionally, it was confirmed that the germination potential of CaDPA, which does not rely on nutrient receptors, is a widespread germination trigger across spore formers. Understanding germination mechanisms and the limitations of different germination paths is important for the development of multi-hurdle approaches to achieve commercial sterility with reduced thermal load.     

Moiety and linker site heterologies for highly sensitive immunoanalysis of cyprodinil in fermented alcoholic drinks

Cyprodinil is a new-generation anilinopyrimidine fungicide widely used in crop protection and frequently found in fruits. In this study, novel derivatives of cyprodinil with linker site heterologies were synthesized and employed in order to produce antibodies with enhanced affinity. Moreover, moiety-heterologous haptens were designed and prepared for assay sensitivity improvement. Two competitive enzyme-linked immunosorbent assays for the analysis of this active substance were developed using direct and indirect formats, achieving IC₅₀ values around 0.15 μg/L. Analytical figures of merit and usability of the optimized assays were evaluated with wine and cider as model food processed matrices. The obtained recoveries were from 90% to 120%, and the limit of quantification was in the 1–5 μg/L range. Finally, a monitoring study (n = 150) was performed to estimate the occurrence and the concentration of cyprodinil in commercial wine and cider products from different origins. We found that 28% of the analysed wine samples contained cyprodinil residues at levels higher than 5 μg/L.     

The efficacy of disinfectant misting in the lairage of a pig abattoir to reduce Salmonella and Enterobacteriaceae on pigs prior to slaughter

Water misting/showers are used in abattoir lairages to improve meat quality, and to cool and calm pigs after transport and during hot weather. One novel approach, which has not been investigated to date, is to add a disinfectant to the misting water as a means of topically reducing Salmonella on pigs prior to slaughter, thereby potentially controlling this organism in the abattoir. The objective of this study was therefore to evaluate misting with water or with Virkon^® S (an approved disinfectant for use in the presence of animals), for their ability to topically reduce Salmonella on high seroprevalence pig herds before stunning and to reduce Enterobacteriaceae.Three experimental groups were investigated: control group (i.e., no misting); water group (misting with cold, 15–17 °C, water, herein referred to as water); and a disinfectant group (misting with 0.5% Virkon^® S). As pigs entered the abattoir, each animal was swabbed along its back before being allocated to its experimental group. Each group was randomly assigned to one of 3 lairage pens that were separated by non-trial pens. After 30 min of misting with water or disinfectant, pigs were moved to the stunning area, where each pig was again swabbed, as above. Swabs were analyzed for the presence of Salmonella and enumeration of Enterobacteriaceae.Before misting, Salmonella prevalence on the pigs was 79.0%, 72.1% and 83.6% for the control, water and disinfectant groups, respectively. After misting, Salmonella prevalence increased to 94.3% in the water group; whereas for the disinfectant group, the prevalence increased marginally to 85.9%. No change in Salmonella prevalence was detected for the control group. In line with the Salmonella results, no significant differences were observed in Enterobacteriaceae counts in the control group at either time point (4.37 and 5.01 log₁₀ CFU/cm², respectively) or in the disinfectant group before and after misting (4.02 and 4.26 log₁₀ CFU/cm², respectively). However, a 2.3 log₁₀ CFU/cm² increase in Enterobacteriaceae was recorded for the water group after misting as compared to before misting (p < 0.05).Since misting with water alone increased topical Salmonella contamination on pigs before slaughter, a risk assessment based on known Salmonella data, meat quality and welfare is recommended to determine whether its use is justifiable. On the other hand, the findings from this study suggest that misting with Virkon^® S at 0.5% could have a role in topical antisepsis of pigs contaminated with Salmonella prior to slaughter and as such this warrants further investigation.     

Prevalence and antimicrobial resistance of Salmonella isolated from an integrated broiler chicken supply chain in Qingdao,China

The present study analyzed the prevalence and antimicrobial resistance of Salmonella along an integrated broiler chicken supply chain. A total of 172 Salmonella isolates were recovered from 1148 samples collected from four sample sources (breeder farms, broiler farms, abattoir, and retail markets), representing nine production stages. These Salmonella isolates were examined for antimicrobial susceptibility to 12 different antimicrobial agents using a disk diffusion assay. Among them, 168 were identified as six different serotypes of Salmonella enterica. The predominant serotype was S. Enteritidis (n = 116), followed by S. Infantis (n = 18), S. Gueuletapee (n = 16), S. Derby (n = 12), S. Meleagridis (n = 4), and S. London (n = 2). The remaining four isolates were serogroup-untypeable. A majority of the 172 isolates (96.51%) was resistant to one or more antibiotics and 61.05% of the Salmonella isolates showed a multidrug resistance phenotype. Statistical analysis indicated the one risk product stage for Salmonella contamination occurred in the sample source at the abattoir, specifically the stage of Carcasses after chilling. The majority of S. Enteritidis isolates shared the same pulsed-field gel electrophoresis (PFGE) cluster, suggesting that the S. Enteritidis strain might spread along the broiler chicken supply chain. The prevalence and antimicrobial resistance of Salmonella in different production stages suggest the importance of controlling Salmonella in the broiler chicken supply chain for public health, underlying the need for improved measures of reducing carcass contamination in abattoirs and the appropriate use of antimicrobials in broiler flocks.     

Bioaccessibility and changes on cylindrospermopsin concentration in edible mussels with storage and processing time

The alkaloid cylindrospermopsin has been recognized of increased concern due to the global expansion of its main producer, Cylindrospermopsis raciborskii. Previous studies have shown that bivalves can accumulate high levels of cylindrospermopsin. Based on the potential for human health risks, a provisional tolerable daily intake of 0.03 μg/kg-body weight has been recommended. However, the human exposure assessment has been based on the cylindrospermopsin concentration in raw food items. Thus, this study aimed to assess the changes on cylindrospermopsin concentration in edible mussels with storage and processing time as well as cylindrospermopsin bioaccessibility. Mussels, (Mytilus galloprovincialis) fed cylindrospermopsin-producing C. raciborskii, were subjected to the treatments and then analyzed by LC-MS/MS. Mussels stored frozen allowed a significantly higher recovery of cylindrospermopsin (52.5% in 48 h and 57.7% in one week). The cooking treatments did not produce significant differences in cylindrospermopsin concentration in the mussel matrices (flesh), however, cylindrospermopsin was found in the cooking water, suggesting that heat processing can be used to reduce the availability of cylindrospermopsin. The in vitro digestion considerably decreased the cylindrospermopsin availability in uncooked and steamed mussels, highlighting the importance in integrating the bioaccessibility of cylindrospermopsinin in the human health risk assessment.     

Validation of real-time PCR for detection of six major pathogens in seafood products

Seafood can pose a public health concern to consumers. It is often consumed raw and may be contaminated with several foodborne pathogens. In order to guarantee the safety of seafood, real-time polymerase chain reaction (PCR) protocols may be used as these enable results to be provided within 24 h.The first goal of our work was to develop real-time PCR protocols enabling the detection of six foodborne pathogens that may be present in seafood products (Campylobacter jejuni, Campylobacter coli, enterohemorrhagic Escherichia coli, Salmonella spp., Vibrio parahaemolyticus, and Vibrio vulnificus). The corresponding gene targets were: 50S/VS1, rfbE, ttr, tlh, and vvp. A multiplex PCR was also developed to detect the virulence genes of V. parahaemolyticus: tdh and trh. A total of 420 bacterial strains belonging to four different genera/strains were used in this study. Sensitivity and specificity were always 100%, except in the case of Salmonella spp., where three strains were not detected by our PCR protocols.The second objective of our work was to assess the detection limit of our real-time PCR protocols on artificially contaminated seafood products (raw shrimps, cooked shrimps, and raw mussels), purchased in public stores. Six different levels of contamination were assayed in four replicates for each matrix. The real-time PCR protocols enabled a better level of detection than the ISO methods, except for Salmonella in raw shrimps and for V. vulnificus in shrimps (raw and cooked). The estimated level of detection was between 1 and 47 cfu/25 g sample for the ISO norms and between 1 and 315 cfu/25 g sample for the real-time PCR protocols tailored in our work.The real-time PCRs developed in our work allowed for good selectivity, sensitivity, and specificity. The sensitivity on seafood products was estimated at a level of 100%, except for Salmonella (97%). In the spiking assays, the levels of detection were lower with the real-time PCR protocol than those obtained with the ISO method. This was not the case for V. vulnificus in raw and cooked shrimps and for Salmonella in raw shrimps.These real-time PCR protocols appear to be good alternative methods for surveillance of seafood products to ensure the absence of foodborne pathogens.One additional conclusion is that laboratories have to use enrichment media that are compatible with those recommended by ISO standards. This may facilitate the isolation of the pathogen if the real-time PCR protocol gives a suspect positive signal during the first step of the seafood analysis.     

Mycological quality and mycotoxin contamination of Sri Lankan peppers (Piper nigrum L.) and subsequent exposure assessment

The aim of the study was to characterize the toxigenic moulds and to screen different mycotoxins in peppers (Piper nigrum L.) of Sri Lankan origin. Aspergillus flavus, Aspergillus parasiticus, Aspergillus niger and Penicillium spp. were found to be the most dominant fungi. Characterization of the moulds was carried out in A. flavus and parasiticus agar (AFPA) and malt extract agar (MEA) in 77 black pepper (BP) and 11 white pepper (WP) samples. In total, 73% of the BP and 64% of the WP samples were contaminated with A. flavus and/or A. parasiticus (AfAp). A BP sample with water activity (a_w) 0.70 recorded the highest count of AfAp (4.3*10⁴ CFU/g). Moreover, 75% of the BP samples exceeded the safe a_w limit (0.65) set by the European Spice Association (ESA). The frequency of occurrence of A. niger in BP was 62% with counts up to 1.3*10³ CFU/g. Penicillium spp. were found in 61% and 55% of the BP and WP samples, respectively. In BP 94% of the samples had a Penicillium contamination below 10³ CFU/g. Other Aspergillus spp, found in peppers included, Aspergillus terrus, Aspergillus tamarii, Aspergillus candidus, Aspergillus penicilloides, Aspergillus sydowii and Aspergillus fumigatus. Mould counts in BP (10²–10⁴ CFU/g) were significantly higher than that of WP (<10² CFU/g). Apart from the occurrence of “classical mycotoxins” of spices, aflatoxins (<LOQ-18 μg/kg) and ochratoxin A (<LOQ-79 μg/kg), other toxins including fumonisin B1 (<LOQ-135 μg/kg), sterigmatocystin (<LOQ-49 μg/kg) and citrinin (<LOQ-112 μg/kg) were detected in peppers. In total, 63% of the BP samples were contaminated with at least one mycotoxin. Mycotoxin contamination in WP was significantly less compared to BP. The exposure to aflatoxins and ochratoxin A by consuming pepper remains harmless considering the existing pepper dietary intake data of the Sri Lankan population.     

Combined effect of sugar content and pH on the growth of a wild strain of Zygosaccharomyces rouxii and time for spoilage in concentrated apple juice

The objective of this study was to evaluate the combined effect of sugar content (66–70 °Brix) and pH (2.0–3.5) on the growth of a wild strain of Zygosaccharomyces rouxii B-WHX-12-54 by response surface (RS) methodology. Experiments were performed in concentrated apple juice inoculated with this strain at standard storage condition (isothermal, 25 °C) for 60 days. Results show that pH was the most significant limiting factor that affects the growth parameters (potential maximum growth rate and lag phase duration), although the effect of sugar content was also significant. In a second experiment, the time for spoilage (TFS) by this strain in concentrated apple juice was assessed under isothermal (25 °C) and non-isothermal conditions, in an attempt to simulate standard storage and overseas shipping temperature conditions, respectively. Results show that pH was again the environmental factor with the highest effect on delaying the spoilage of the product caused by this strain. Although concentrated apple juice stored under non-isothermal condition showed lower microbial stability (evidenced in lower TFS values) than that stored under standard isothermal condition, a pH value below 2.3 was sufficient to extend the shelf life of the product to more than 60 days under both temperature conditions. The results obtained in this study could be used by producers and buyers to predict and control the growth and TFS of Z. rouxii strain B-WHX-12-54 in concentrated apple juice.     

Aflatoxin B1 production by Aspergillus parasiticus and strains of Aspergillus section Nigri in currants of Greek origin

Aflatoxin B₁ (AFB₁) mostly produced by Aspergillus flavus and Aspergillus parasiticus, is an extremely toxic and carcinogenic metabolite. Currants are used in the Mediterranean diet as a food with antioxidant properties. Four strains of Aspergillus section Nigri have been isolated from currants originated from Crete and Corinth. In this study AFB₁ production by A. parasiticus and the four strains of Aspergillus section Nigri in Cretan and Corinthian currants (Vitis vinifera L.) is investigated. AFB₁ determination was performed by HPLC–FID. Results revealed that the four strains Aspergillus section Nigri, as well as the aflatoxigenic strain A. parasiticus produced AFB₁ (0.0052–1.31 μg AFB₁ 15 g⁻¹, corresponding to 0.0003–0.087 μg AFB₁ g⁻¹) in both type of currants (Cretan and Corinthian) on the 12th day of observation. Moreover, AFB₁ production, by A. parasiticus in the synthetic Yeast Extract Sucrose (YES) medium was also studied. The ability of AFB₁ production has been affected by the special characteristics of each isolate and the currants substrate.     

Contamination of Opisthorchis viverrini and Haplorchis taichui metacercariae in fermented fish products in northeastern Thailand markets

Consumption of raw or inadequately cooked cyprinid fish as well as related products (often contaminated with Opisthorchis viverrini and/or Haplorchis taichui) is one of the major causes of fish-borne trematode (FBT) infection, which is still endemic in the Greater Mekong Subregion including northeastern Thailand. This study surveyed FBT metacercariae (FBTM) in fermented fish dishes (pla-ra and pla-som) obtained from 73 local markets in 20 provinces of northeastern Thailand during April to November 2011. Fish were identified and examined for FBTM under a microscope. In addition, the coexistence of H. taichui in O. viverrini-positive samples was confirmed by multiplex PCR. FBTM were detected in fermented fish dishes from markets located in five provinces: Si Sa Ket, Sakon Nakhon, Mukdahan, Khon Kaen and Udon Thani. FBTM contamination was found in 9.58% (7/73) of markets, mainly in pla-ra. FBTM were found in four species of fish: Henicorhynchus siamensis, Puntius bimaculatus, Puntius orphoides and Hampala dispar. Multiplex PCR revealed 186 and 330 bp PCR products in most of FBTM-positive samples, indicating the coexistence of H. taichui and O. viverrini in fermented fish dishes. These results suggest that fermented fish dishes are frequently contaminated with FBTM and may serve as important sources of FBT infection in people who typically eat raw or undercooked fish dishes. This study might provide evidence leading to improved public health awareness for surveillance and control of FBT contamination in fermented fish dishes.     

Species determination of pine nuts in commercial samples causing pine nut syndrome

Consumption of pine nuts from the species of Pinus armandii has been reported to cause dysgeusia, commonly known as pine mouth, or pine nut syndrome (PNS). However, the number of reports on pine nut consumptions of the different species and PNS is limited. This leaves open the possibility that other pine species than P. armandii could be involved in PNS as well. This study investigated 18 samples involved in PNS and received at the Danish Veterinary and Food Administration in 2011 through 2012. Samples were subjected to gas chromatographic analysis of fatty acids. The content of 11 individual fatty acids was used together with the diagnostic index and the sum of Δ5-fatty acids as diagnostic parameters. Diagnostic parameters from samples were then compared to reference material and literature data to determine the species. In a limited number of samples, the diagnostic parameters matched neither our reference materials nor literature data. However, the morphology, the fatty acid analysis, and externally obtained DNA sequencing data suggest a P. armandii subspecies or a variety. With these possible P. armandii subspecies, P. armandii was identified in all analyzed samples. The application of principal component analysis (PCA) to the data set showed a satisfactory separation of the majority of the 13 pine species included in the study.     

A structural modeling on food safety knowledge,attitude, and behaviour among Bum Bum Island community of Semporna,Sabah

The objective of this study was to evaluate the relationship among food safety knowledge, attitude and behavior in Bum Bum Island community, Semporna, Sabah. Proportional stratified sampling method was used in this survey. A total of 250 respondents were selected randomly from ten villages in Bum Bum Island. Face-to-face interview was conducted to complete the questionnaire. In general, respondents exhibited average food safety knowledge level especially in their awareness of personal hygiene and kitchenware hygiene. Food safety attitude of the community was found strongly affected their food safety behavior in positive way, which was proven by the highest standard β among variables tested (β₁ = 0.885, p < 0.05). However, food safety knowledge was negatively affected the food safety behavior of the respondents (β₁ = −0.128, p < 0.05). Our result confirmed that Structural Equation Modeling (SEM) was successfully used to model the relationship among food safety knowledge, attitude and behavior.     

Development and validation of an LC–MS/MS/MS method for the quantification of fluoroquinolones in several matrices from treated turkeys

The study presents a sensitive and reliable confirmatory method for the extraction, identification, quantification of five fluoroquinolones (FQ) namely enrofloxacin, ciprofloxacin, difloxacin, sarafloxacin and flumequine, in plasma, liver, kidney, muscle, skin + fat, lung and intestinal content from turkeys.For the extraction and matrix clean-up of FQ residues from all biological matrices, the Quick Easy Cheap Effective Rugged Safe (QuEChERS) methodology was adopted; only for plasma samples acetonitrile was used.The analyses were performed by liquid chromatography with mass spectrometry detection (LC–MS). LC separation was performed on a C18 Kinetex column (100 × 2.1 mm, 2.6 μm, Phenomenex, CA, USA) with gradient elution using ammonium acetate solution (10 mM, pH 2.5) and methanol containing 0.1% formic acid. Mass spectrometric identification was done using an LTQ XL ion trap (Thermo Fisher Scientific, CA, USA), with a heated electrospray ionization probe, in positive ion mode.The method was validated according to the European Legislation (decision 2002/657/EC) and EMA guideline (EMA/CVMP/VICH/463202/2009); selectivity, linearity response, trueness (in terms of recovery), precision (within-day repeatability and within-laboratory reproducibility), limit of detection, limit of quantification, decision limits, detection capability, absolute recovery and robustness were evaluated using turkey blank matrices. All data were within the required limits established for confirmatory methods except for flumequine which presented a recovery value slightly higher than 110% in muscle and intestinal content. For all FQs, all the extraction rates were greater than 70% and limits of quantification ranged from 1.2 μg kg⁻¹ to 118.8 μg kg⁻¹.This fast and robust method was suitable for the identification and quantification of FQ residues in tissues, plasma and intestinal content as confirmed by data obtained from incurred samples of turkeys treated at farm for therapeutic purposes.