查看更多>>摘要：The influence of high-pressure carbon dioxide (HPCD) treatment on the browning of fresh-cut lettuce was investigated during storage at 4 degrees C. The browning degree, color, weight loss, browning-related enzymes, and components related to membrane lipid metabolism of fresh-cut lettuce were assessed during storage. The results showed that HPCD treatment slowed down the browning of fresh-cut lettuce. Polyphenol oxidase activity and total phenolic content of HPCD-treated group were reduced by 53.50% and 74.63%, respectively. In addition, HPCD treatment inhibited lipoxygenase activity and delayed membrane lipid peroxidation, thus decreasing PAL's stimulation by membrane lipid peroxidation products and further reducing the synthesis of phenolic. On the other hand, HPCD treatment maintained the structural integrity of the cell membrane and prevented the cell membrane compartmentalization from being broken due to cell membrane breakage by inhibiting phospholipase D activity, which avoided the contact between enzyme and phenol and delayed the oxidative browning.
查看更多>>摘要：Cross-contamination is a key food safety risk during both harvesting and post-harvest processing of fresh produce. Very few effective intervention approaches are available for reducing cross-contamination risks from diverse food contact surfaces during harvesting and post-harvest processing. Therefore, developing an effective antimicrobial coating that can be simply applied on a diversity of food contact surfaces is highly desirable. This work demonstrates a cost-effective and one-step antimicrobial coating approach that can be applied on diverse food contact surfaces, such as plastic films, Sparta brushes, and polyfoam sponges. The incorporation of chlorine charged antimicrobial yeast cell wall particles (YCWPs) into chitosan-based coatings provides unique advantages in achieving a high concentration of chlorine on food contact surface and extending the stability of chlorine. Approximately 583 nmol/cm2 of active chlorine bound to the coated poly(vinyl alcohol-co-ethylene) (PVA-coPE) film surface after 60 min of incubation with bleach at room temperature, which enabled a significant antimicrobial activity of this coating. An inactivation of approximately 3-log and 5-log units of Listeria innocua with organic load (COD = 500 mg/L) were achieved after treatment for 2 min and 5 min, respectively. This antimicrobial coating with chlorine charged YCWPs effectively reduce the cross-contamination between fresh produce and plastic films. Baby spinach leaves were selected as a model fresh produce. The results represent that chitosan-YCWPs coatings led to more than 3 log reduction in the bacterial population transferred to leaf surface upon 10 min of contact with contaminated plastic films, while native chitosan without chlorine charged YCWPs coating did not result in any significant reduction. The results in this study also demonstrate the feasibility of using this antimicrobial coating on contaminated sponges and brushes to reduce cross-contamination of fresh produce during washing steps. No bacterial cells were detected from the leaf surface after contact with contaminated sponges or brush samples coated with chitosan and chlorine-charged YCWPs. This cost-effective and one-step antimicrobial coating approach with a high potential of scale-up will significantly enhance the efficacy of surface sanitation and prevent the cross-contamination of fresh produce.
查看更多>>摘要：Listeria monocytogenes is a kind of foodborne pathogen, which can cause meningitis, septicemia, gastroenteritis, and abortion with a fatality rate of up to 30%. Rapid, sensitive, and convenient detection of L. monocytogenes in food is an important strategy for controlling contamination and infection. In this study, an enhanced visual detection assay for L. monocytogenes based on an isothermal amplified peroxidase-mimicking catalytic beacon was developed. When L. monocytogenes existed, G-quadruplex sequences were amplified together with targeted gene sequence by polymerase spiral reaction (PSR). G-quadruplex adequately formed DNAzyme with hemin to have an enhanced peroxidase-like bioactivity with help of Nb. BbvCI nicking endonuclease, which could display significant colorimetric signals for indicating positive results qualitatively. The sensitivity test results determined that our assay enabled the quantitative detection of L. monocytogenes ranging from 10 to 10(5) CFU mL(-1), as well as had a detection limit of 3.1 CFU mL(-1), which was lower than previous visual detection assays for L. monocytogenes. Besides, it was notable that this assay could detect L. monocytogenes with the concentration of 2.0 lg CFU/g in artificially contaminated pork samples within about 4 h, with the advantages of high sensitivity, simple operation, and good visual signal output. We believed the improved visual detection assay based on isothermal amplified peroxidase-mimicking catalytic beacon showed great potential for food safety analysis.
Sharafi, KiomarsMatin, Behzad KaramiOmer, Abdullah KhalidMansouri, Borhan...
11页
查看更多>>摘要：Mycotoxins, predominantly aflatoxin M1 (AFM1), require better quality control in infant formula milk (IFM). This study aims to use a systematic review study to estimate the amount and health risk assessment of AFM1 of IFM for infants less than one year old in the last two decades worldwide. For this purpose, a systematic search was conducted from June 27, 2000, to April 5, 2021. Two hundred and twelve articles and reports were obtained from various databases, and twenty of them were eventually chosen for the current study based on the study's selection criteria. Due to a lack of access to the raw data of the studies obtained, EXCEL re-simulated the data of each of these studies, keeping in mind the mean, standard deviation, and sample size of each study. The statistical analysis, health risk assessment, uncertainty analysis, and sensitivity analysis for AFM1 of IFM were then done on the simulated data by country, continent, and globally. Based on the compliance of AFM1 of IFM with the European Community (EC) standard (25 ng/kg), and also according to the results of health risk assessment, the quality of IFM provided to the market in most countries in the last two decades in terms of the AFM were at a high level and has been unauthorized. Therefore, it is necessary to pay special attention to continuous monitoring and control measures for AFM1 in consumer IFM over all countries worldwide. Due to the limited current information about AFM1 of IFM in the world, further studies are necessary.
Roungchun, Jiahleen B.Tabb, Amanda M.Hellberg, Rosalee S.
8页
查看更多>>摘要：Accurate species identification methods are needed to combat tuna fraud, improve tuna stock regulation, and mitigate health risks associated with mislabeled tuna products. The objective of this study was to conduct a market survey of raw and processed tuna products using a DNA mini-barcoding system based on the mitochondrial control region (CR). A total of 80 samples of raw, dried, and canned tuna products were collected at the retail level for CR mini-barcoding analysis. The samples underwent DNA extraction, polymerase chain reaction (PCR), and DNA sequencing of the 236-bp CR mini-barcode. The resulting sequences were searched against GenBank using the nucleotide Basic Local Alignment Search Tool (BLAST) to determine the species. The study achieved species identification for 100% of the raw samples, 95% of the dried samples, and 50% of the canned samples, for an overall success rate of 86% (69/80 samples). Mislabeling occurred in 11 of the identified samples (16%), including 8 products marketed as raw, dried, or canned yellowfin tuna, 2 samples marketed as dried or canned skipjack tuna, and 1 raw fillet sold as bluefin tuna. Overall, the DNA mini-barcoding system proved to be a promising method in identifying tuna species in both raw and processed samples. However, testing with a secondary marker is required in some cases to resolve instances of possible species introgression. Future research should explore optimization of this method for improved identification of canned tuna samples.
查看更多>>摘要：Bisphenol A (BPA) as the most common endocrine disruptor used in food containers and packaging is causing adverse effects for human beings. Accordingly, in situ detection of BPA is of practical importance for food safety. However, the complicated operations of existed methods and interference of various impurities in food matrix restrict the realization of real-time in situ BPA sensing in food samples. We report here a portable and fully-integrated electrochemical sensing device with an injector as the reaction vessel which assembled with screen printed electrodes (SPEs) as sensing electrodes and a detachable filter unit to filter impurities. This device, namely lab-on-injector, reduces the sampling, pretreatment and detection to a simple on-step operation, making in situ detection of BPA in real samples much easier and more feasible. Moreover, extra-small Au nanodots confined in carbon nanofibers (AuNDs@CNFs) were synthesized by in situ carbothermic reduction of Au3+ absorbed on cellulose, and were used to modified SPEs surface to greatly enhance detection performance of the lab-on-injector. Using this AuNDs@CNFs based lab-on-injector, BPA in food matrix was detected directly with recoveries from 93.14% to 94.25%, demonstrating a reliable platform for in situ detection of BPA, and opening a new way for the development of smart devices in electroanalysis. The electrochemical behaviors of BPA oxidation on AuNDs@CNFs/GCE were further explored. CVs of AuNDs@CNFs/GCE with different scan rates were recorded (Fig. S4). Whether the electrochemical reaction of BPA is a diffusion-controlled or surface-controlled process can be determined by the following equations.
查看更多>>摘要：The integration of loop-mediated isothermal amplification (LAMP) onto a microfluidic chip adds more simplicity and portability for food safety control. However, this system for multiple-target detection was less used on foodborne bacteria. Here, we utilized a ten-well microfluidic chip with pre-loaded LAMP primer sets for the quantitative and qualitative detection of Salmonella, Staphylococcus aureus, Escherichia coli O157:H7, and Shigella. The specificity and sensitivity of designed primers targeting sirA, spA, fliC, and ipaH genes were validated. Using regular tubes and the ten-well microfluidic chips, these four pathogens could be simultaneously detected within 45 min by LAMP with fluorescent and colorimetric readouts, respectively. Finally, the results demonstrated that the limit of detection reached 8 x 10(3) CFU mL(-1) genomic DNA with a recovery rate of 86.1%similar to 110%. In summary, our microfluidic chip platform displayed obvious advantages in time-saving, cost-effectiveness, and sensitivity, which is applicable for in-field monitoring of food pathogens.
查看更多>>摘要：Milkfish has become most often associated with histamine fish poisoning recently in Taiwan, but no information regarding the use of high pressure for preservation on this fish flesh. The microbial quality and physicochemical properties of milkfish flesh pressurized at 200, 300, 400, 500, and 600 MPa for 5 min were evaluated. In addition, the retardation effects in microbial growth and quality loss of pressurized milkfish flesh stored at 4 degrees C and 15 degrees C were investigated. The results showed that the L* (lightness), W (whiteness), Delta E (color difference), and texture (hardness, cohesiveness and chewiness) of fish flesh increased significantly with the increase in pressure, whereas the a* (redness) value of samples significantly decreased, indicating that high pressure can cause negative effects in texture and color of fish flesh. Furthermore, the aerobic plate count (APC), psychrotrophic bacteria count (PBC), and coliform decreased with the increase in pressure. The samples pressurized more than 300 MPa had significantly lower levels of total volatile basic nitrogen (TVBN) than unpressurized sample. In addition, high pressure above 300 MPa delayed the production in TVBN and histamine content in milkfish flesh stored at low temperatures (4 degrees C and 15 degrees C), whereas the delaying effect on the increase of APC and PBC was significant at higher pressures (>400 MPa). However, compared with 15 degrees C, high pressure combined with low temperature storage at 4 degrees C more significantly delayed the changes in microbial and chemical quality. In conclusion, the results indicated that pressurization at 400 MPa for 5 min on milkfish flesh was able to prevent deterioration and quality loss, and extend the shelf life during storage at low temperatures, even though it can cause changes to fish flesh texture and color.
Hasselberg, Astrid EliseNostbakken, Ole JakobAakre, IngerMadsen, Lise...
11页
查看更多>>摘要：Inadequate nutrient intakes are frequent among young children in low- and middle-income countries, causing prevalent micronutrient deficiencies. In Ghana, small smoked fish are the most frequently consumed animal source foods, and both whole fish and different tissues of fish are commonly used in complementary foods. However, the risks and benefits associated with consumption of different tissues of smoked fish has not been explored. Samples of smoked European anchovy (Engraulis encrasicolus) were collected from five regions in Ghana and divided into subsamples of different tissues: whole fish, heads and skin, and samples without heads and skin. The different tissues were subsequently analyzed for selected nutrients (vitamins, minerals, trace elements and fatty acids), heavy metals and polycyclic aromatic hydrocarbons. A scenario referencing young children in Ghana (aged 6-23 months) was developed to assess the risks and benefits associated with daily consumption of different tissues of smoked European anchovy. We found that all tissues had the potential to substantially contribute to the recommended nutrient intakes of vitamins, minerals and essential fatty acids important for young child development. Samples of whole fish and of heads and skin contained levels of cadmium which exceeded the tolerable weekly intake greatly in the current scenario. All tissues contained elevated concentrations of BaP and PAH4 which exceeded the margin of exposure in the scenario, entailing potential consumer risk. A thorough assessment of dietary intakes of smoked fish products and refined risk-benefit assessments are therefore imperative to secure safe utilization of smoked fish in Ghana.
查看更多>>摘要：Natural pH-responsive indicator films usually used in smart packaging can real-time monitor the changes of food quality. The pH-responsive colorimetric indicator films based on natural ingredients show good pH-sensitivity and growing population, which safely and environmentally indicate food quality. Recently, the application of natural pigments and polymer carriers shows great potential in smart packaging based on pH-responsive indicator. This article mainly reviews the application and progress of natural pigments (e.g. anthocyanins, betalains, carotenoids, chlorophyll, curcumin) and natural polymer carriers (e.g. chitosan, gum, starch, plant protein, and milk-based protein) in pH-responsive colorimetric indicator films, and also further discusses the main problems and corresponding methods to improve performances of current pH-responsive colorimetric indicator films.
NSTL
Elsevier