查看更多>>摘要：A cross-sectional study was conducted among 290 chicken vendors by using a structured pretested questionnaire to evaluate the knowledge, attitude, and practices on food safety and foodborne pathogens at wet markets in Dhaka, Bangladesh. The result shows that a considerable number of vendors were illiterate (44.1 %) followed by primary school leaver (39.7 %) and secondary school degree (15.9 %) and no one had any food safety training and health certificate. The vendor's knowledge and safety practices were below an acceptable level with the mean value of 8.53 +/- 6.28 and 5.53 +/- 2.53 respectively. Vendors had satisfactory knowledge on food safety (70 %) while unsatisfactory knowledge on antimicrobial resistance (20 %), zoonoses (26.5 %), foodborne pathogen (38.6 %), and Salmonella (13.1 %). Besides, about 63.8 % of chicken vendors had a good attitude on food safety with a mean of total score of 8.35 +/- 4.99. Almost every vendor had an acceptable level of knowledge and attitude about hand washing, uses of personal protective devices (apron, hand gloves, and mask), cleaning of utensils (knife and chopping board), proper disposal of wastages, drainage, and regular cleaning of shops with disin-fectant. A statistically significant correlation was found between the level of education and knowledge (p < 0.05); education and practices (p < 0.05); experiences and practices (p < 0.05); age and practices (p < 0.05). There was also a statistically significant correlation found between level of education and income (p < 0.05); age and income (p < 0.05). Chi2 analysis did not disclose any significant relationship between knowledge, attitude, and practices. Continuous education, hands-on training, awareness, and motivation for vendors are recom-mended to improve their food safety knowledge and practices.
Mohamed, Hussein M. H.Burroughs, SamanthaEmch, Alex W.Waite-Cusic, Joy...
8页
查看更多>>摘要：The main objective of this study was to quantify reduction of Salmonella and Listeria monocytogenes during salami production phases. Salami batter was prepared, inoculated with Salmonella and L. monocytogenes, stuffed into casings (50 and 80 mm), and subjected to four processing trials (A-D). Trials A/B included fermentation (32 degrees C, 95% RH, 24 h) and drying (15 degrees C, 72% RH, 31 d). Trials C/D were identical except 80 mm salami were dried 60 d and both diameters completed an additional finishing phase (21 degrees C, 50% RH, 20-30 d). After drying, pathogen populations were reduced by < 3 log CFU/g. Extended drying of 80 mm salami significantly improved reduction of L. monocytogenes (0.9 +/- 0.6 log CFU/g (30 d) versus 2.1 +/- 0.9 log CFU/g (60 d)). Inclusion of a finishing phase supported total reductions of >5.4 and > 4.9 log CFU/g of Salmonella and L. monocytogenes, respectively. Results confirmed fermentation and drying may be insufficient to achieve pathogen reduction but demonstrated a finishing phase can be an effective lethality strategy.
查看更多>>摘要：The Atlantic horse mackerel (Trachurus trachurus) is a commercially important fish species. Most parasitological studies on the anisakid nematodes occurrence in T. trachurus to date have involved fish from the Atlantic Ocean, while few studies are available for the Mediterranean Sea. Since T. trachurus is used raw and cooked in Ligurian cuisine (northwest Italy), assessment of possible consumer health risks (i.e., anisakiasis and allergic issues) is warranted. With this study we investigated the occurrence of zoonotic anisakid nematode larvae in the Atlantic horse mackerel. Between 2017 and 2019 a parasitological survey was carried out on 481 T. trachurus from four commercial fishing areas (Sanremo, n = 45; Imperia, n = 30; Savona, n = 300; Arenzano, n = 106) in the Ligurian Sea (western Mediterranean Sea). All isolated larvae morphologically assigned to the genus Anisakis (n = 937) were identified as A. pegreffii by PCR-RFLP. The total prevalence of A. pegreffii was 60.9% (95% confidence interval [CI] 56.5-65.3); the prevalence by area was: Savona (89.3%; 95% CI 85.8-92.8) > Imperia (20%; 95% CI 4.8-35.2) > Arenzano (16%; 95% CI 8.9-23.1) > Sanremo (4.4%; 95% CI 0-10.7). Anisakis pegreffii larvae were found in visceral organs (99.15%) and muscle tissue (0.85%). In addition, 411 larvae morphologically referable to the genus Hysterothylacium sp. were also isolated but only in the viscera. This parasitological survey provides new data on the occurrence and the level of anisakid nematode infection in the Atlantic horse mackerel.
查看更多>>摘要：In the European Union (EU), Salmonella is the main zoonotic hazard of interest in pig meat. Contamination occurs during slaughter mainly due to spread of faecal material. In 2020, the Danish competent authorities (CA) raised the question of the risk to humans of Salmonella resulting from bile contamination of pig carcasses. To address this, a study was undertaken involving 1) a pilot study to develop an aseptic way of collecting bile and 2) 299 gall bladder samples collected from finishing pigs from 28 pig herds. The samples were subjected to standard laboratory analysis and none were positive for Salmonella. A simulation model was set up using the collected data, plus data from the Danish meat inspection database as well as expert opinion, retrieved from the CA and the food business operator (FBO). The objective was to estimate the number of carcasses contaminated with Salmonella from bile that could be overlooked if responsibility for handling bile contamination were to rest solely with the FBO. The basic scenario showed that a median of nine (90% C.I.: 0-53) carcasses would be overlooked in a production of 16 million finishing pigs in one year, whereas 103 carcasses (90% C.I.: 7-544) would be overlooked in the worst-case scenario. Compared to the current Salmonella programme, the median relative efficacy of focusing on bile-contamination to detect Salmonella was 0.008% (basic scenario) or 0.087% (worst-case scenario). In conclusion, the risk to human health associated with Salmonella in bile on finishing pig carcasses was calculated to be negligible. Moreover, the FBO's handling of bile contamination prevents bile-contaminated carcasses from leaving the abattoir.
查看更多>>摘要：In this study the labelling compliance of 40 caviar products collected from a major Chinese Business to Customer online platform was assessed. The label information was analyzed according to the requirements of the Chinese standard for prepackaged food and of the Convention on International Trade in Endangered Species (CITES) Resolution on Conservation and trade in sturgeons and paddlefish. A molecular analysis based on DNA barcoding targeting two mitochondrial genes (COI and cytb) was used to support the label assessment. All products were fully compliant to the national labelling standard, and they were verified as belonging to Chinese producing plants. On the contrary, CITES requirements were never satisfied and no reference to the production method (wild catch or aquaculture) and to the origin of the roes processed for caviar production was reported. The sturgeon species or hybrid were declared in 32.5% of the products. Despite the limits in discriminating among Acipenser spp. and commercial hybrids, the molecular analysis was confirmed as an effective screening tool to monitor products authenticity. The molecular analysis highlighted no counterfeiting with heterologous species, being all the products confirmed as sturgeon species. However, 42.5% of the products did not fully match their label information. Evidences from the study stressed the need to fill an evident gap in the traceability of caviar products by promoting the use of CITES labelling to ensure products fair trade and sustainability, as well as consumers protection.
查看更多>>摘要：Pathogenic bacteria cause disease outbreaks and threaten human health, which prompts the research on advanced detection assays. Herein, based on the fluorescence resonance energy transfer (FRET) between upconversion nanoparticles (UCNPs) combined with aptamers and black hole quencher 1 (BHQ-1) ligated with cDNA, a fluorescence sensing platform was developed for specific and sensitive detection of pathogenic bacteria. The desirable distance (less than 10 nm) between UCNPs (donor) and BHQ-1 (acceptor) for FRET was achieved via the base pairing of aptamer and cDNA. Furthermore, the fluorescence emission spectrum of UCNPs and the absorption spectrum of BHQ-1 overlapped well, which enabled the occurrence of FRET and caused fluorescence quenching. Stable stem-loop structures might be the structural basis for the aptamer to specifically recognize target bacteria. In the presence of target bacteria, UCNPs-aptamer preferentially captured the bacteria, which decreased the UCNPs-aptamer-cDNA-BHQ-1 complex and caused fluorescence recovery. Using this sensing platform, we successfully detected one strain of S. aureus, ATCC 29213, with a limit of detection (LOD) of 6 cfu/ mL in the linear range of 36-3.6 x107 cfu/mL and have verified this method in relevant food samples with good recoveries. In the future, the developed assay could also be used to detect other targets by selecting proper aptamers, which further broadens the potential applications of this method.
查看更多>>摘要：Bacillus subtilis CW14 and beta-glucanase produced were used to inhibit Aspergillus ochraceus, for detecting its antifungal activity and exploring the mechanism. Results showed that CW14 supernatants with molecular weights (Mw) >10 kDa had the best antifungal activity, increased the contents of chitin and active oxygen (ROS), inhibited mycelial growth and spores germination of A. ochraceus, and increased the production of OTA. Besides, it might activate the CWI signaling pathway at the molecular level, and affect its secondary metabolism of A. ochraceus. After LC-MS/MS analysis, the proteins with the antifungal effect of Mw > 10 kDa might be a series of glycoside hydmlase or ribonuclease which inhibit cell wall growth. The antifungal protein beta-glucanase in the CW14 genome was found and was heterogeneously expressed in Pichia pastoris. Its stability and antifungal activity were evaluated, and the antifungal rate reached 97.1%.
查看更多>>摘要：An authenticity-based method was developed to detect economically motivated adulteration (EMA) in milk. To achieve this goal, 46 peptides released from trypsin digested milk proteins were identified and marker peptides were further selected based on their digestibility and stability characteristics to allow further quantifications of the milk proteins in the original samples using an isotope-dilution ultra-performance liquid chromatography tandem triple quadrupole mass spectrometry (UPLC-TQMS). Furthermore, to detect EMA in milk samples, 22 authentic milk powder samples were analyzed using the isotope-dilution UPLC-TQMS, and an authenticity threshold value -70.26 g/100 g as the content of all five major milk proteins to total protein-was established to evaluate milk samples with high adulteration risks. Finally, the threshold value was validated using soy protein adulterated milk samples. Results showed that the reported authenticity-based method was sensitive enough to detect the tampering of milk samples with as little as 10 % soy protein added. It is clear that this newly developed authenticity-based detection method is a powerful tool to detect unknown adulteration risks in milk samples.
查看更多>>摘要：The gene encoding LysSTG2, a novel endolysin from Salmonella-lytic bacteriophage STG2, has been cloned, overexpressed, and characterized previously. In this study, LysSTG2 was used to control Pseudomonas aeruginosa and P. putida, which showed high sensitivity to LysSTG2, in bottled water, milk, chicken breast, salmon, and the biofilms formed on the surface of polystyrene resin and stainless steel. In bottled water, LysSTG2 combined with EDTA reduced the viable counts of P. aeruginosa and P. putida by 2.2 log and to lower than the limit of detection, respectively. However, there was no significant decrease in viable counts in pasteurized milk artificially contaminated with these bacteria. Meanwhile, the addition of 1 mg/mL LysSTG2 alone reduced the viable counts of P. aeruginosa and P. putida by 0.6 log in chicken and 1.1 log in salmon samples contaminated with these bacteria, respectively. Further reduction in viable counts in combination with EDTA was not observed. Additionally, a strong effect of LysSTG2 on the removal of P. aeruginosa and P. putida biofilms was observed on the polystyrene resin and stainless steel surfaces, displaying more than 99.9% decrease in viable biofilm cells after 2 h of treatment at 37 degrees C. The results of this study suggest that LysSTG2 has the potential to control both planktonic and biofilm cells of Pseudomonas. Further investigations are required to optimize and improve the use of the endolysin for application in food and food processing facilities.
Pradana-Lopez, SandraPerez-Calabuig, Ana M.Cancilla, John C.Otero, Laura...
7页
查看更多>>摘要：In this work, a method to detect and quantify melamine in three different powdered milks is presented. The goal has been achieved by training convolutional neural networks (CNN) with a photograph database. The three types of milk are of different brands, each with their own fat content and intended final consumer (age-based distinction). The adulterated samples were prepared by weighing and adding trace amounts of melamine, even reaching samples that are considered to be "melamine-free". A total of 3100 images were taken to develop the CNNs (100 images per group to be classified). Specifically, a ResNet34 model architecture has been used to carry out the classification. For this deep learning approach, the images were randomly divided into two main sets: 90% for the training-validation phase of the CNN and 10% to serve as a blind test. The optimized model showed an overall accuracy of 98.7% during the validation phase, while leading to a 3.0% misclassification rate during blind testing, denoting the effectiveness of the application as a quality and safety control method for the milk industry.
NSTL
Elsevier