查看更多>>摘要：3-monochloropropane-1,2-diol (3-MCPD) is a well-known heat-produced food contaminant, which has been reported to be carcinogenic, nephrotoxic, and reproductively toxic. In this study, a facile electrochemical sensor based on nanoporous gold (NPG) capped with molecularly imprinted polymer (MIP) was constructed for the rapid and selective determination of 3-monochloropropane-1,2-diol (3-MCPD). Firstly, NPG was fabricated on the electrode through coating the glass carbon electrode (GCE) surface with NPG film to provide an ideal substrate for polymerization of the MIP membrane and improve the electrocatalysis activity of the sensor. Then, the MIP membrane was constructed on the NPG surface via self-assembly by electropolymerization to realize selective recognition of target 3-MCPD molecules. As a consequence of the combined effect of NPG and MIP, the optimized molecularly imprinted polymer/nanoporous gold/glassy carbon electrode (MIP/NPG/GCE) sensor exhibited outstanding analytical performance towards 3-MCPD with a much wider linear range from 10(-16) to 10(-7) mol/L and fairly low detection limit of 3.5 x 10(-17) mol/L (S/N = 3). Meanwhile, the constructed electrochemical sensor presented outstanding specificity, anti-interference capability, and reproducibility. In order to demonstrate practical applicability, the MIP/NPG/GCE was applied for the detection of 3-MCPD in real soy sauce and satisfactory results were obtained with recovery rates ranging from 105.90% to 107.52%.
查看更多>>摘要：Mycotoxin contamination of rice (Oryza sativa), especially that from aflatoxins (AFTs), is one of the greatest chemical hazards to humans and animals. However, few studies have investigated the relationships between fungal communities and mycotoxin contamination of rice grains. In the present study, we collected rice grain samples from 10 provinces in the northeastern (NE), southeastern (SE), and southwestern (SW) regions of China, encompassing the major rice-producing areas of China. The Fungal diversities of rice grains were significantly different among different regions and significantly higher in the SE and SW regions compared to the NE region. Geographic location was highly associated with fungal community alpha and beta diversity differences. Environmental variables determined the distribution of fungal communities, with winter mean temperature (WMT), mean annual precipitation (MAP), harvest mean wind speed (HMW), and grain moisture (GM) being the most important factor shaping the fungal communities, and the higher HMW could significantly reduce the abundance of aflatoxigenic fungi and aflatoxins. The Aspergillus flavus and A. parasiticus were defined as the major AFTproducing fungal taxa observed in the SE and SW region communities. The NE region exhibited a lower risk of AFT contamination due to its much lower prevalence of toxigenic fungi. Furthermore, keystone taxa of cooccurrence network analyses indicated that species belonging to the genera Clonostachys, Cryptococcus, Hannaella, Leptosphaerulina, Leptosphaeria, Phaeosphaeria, Sarocladium, Sphaerulina, Wallemia and Ustilaginoidea exhibited abundances that were negatively correlated with AFT-producing fungal abundances and could potentially inhibit the growth of AFT-producing fungi. The results provide potentially important data for the strategic guidance of local rice grains storage in order to better control toxin contamination and improve grain quality.
查看更多>>摘要：Aflatoxin B1 (AFB1) has the strongest carcinogenesis and mutagenesis effects. Herein, a novel ratiometric surface-enhanced Raman scattering (SERS) aptasensor based on graphene oxide (GO) as a corrective internal standard (IS) and signal amplifier was constructed for reliable detection of AFB1. 4-Mercaptobenzoic acid as Raman reporter embedded in Au@Ag core-shell nanoparticles and AFB1aptamer conjugated to the Ag shell acted as the signal probes (Au-4MBA@Ag NPs-AFB1apt). AFB1apt was attached to the surface of GO with Raman signals modified Au NPs/Indium tin oxide glass (GO/Au NPs/ITO) via pi-pi stacking interaction, facilitating further amplification of the signal. With an increase of AFB1 concentration (0.0001 ng/mL-100 ng/mL), the probes were released owing to the affinity of aptamers, causing the decreased 4-MBA intensity (I4-MBA) and unchanged GO intensity (IGO). Therefore, the quantitative test was achieved based on the ratiometric value (I4MBA/IGO). A good negative correlation (R2 = 0.992) was achieved and the limit of detection (LOD) was as low as 0.1 pg/mL, proving the proposed sensor can become an efficient analytical tool and shows a bright application prospect in the food detection field.
von Wuthenau, KristianSegelke, TorbenMueller, Marie-SophieBehlok, Hardy...
9页
查看更多>>摘要：Food fraud is a pervasive issue; products with high sales and region-dependent prices are strongly affected. In this study, isotopolomic fingerprinting was used to distinguish the origin of almonds in order to prevent food fraud. For this purpose, 250 almond samples consisting of more than 30 varieties from six different countries and four crop years were analysed and the chemical profiles were evaluated using chemometric methods. By using log10 as pre-treatment and support vector machine (SVM), a prediction accuracy of 92.2% +/- 0.7% was achieved. The respective harvest year and the underlying almond variety had no significant effect on the origin discrimination.
查看更多>>摘要：This study develops a conceptual framework as a basis for quantitative assessment of food control system in Indonesia to achieve food security and improve public health. Currently, an assessment of the food control system in Indonesia has not been comprehensively carried out. In developing a conceptual framework for a quantitative assessment model in the form of an index for a food control system, a desk study and expert panel discussion were conducted to analyse the existing regulations and policies in effect in Indonesia, the relevant Food and Agriculture Organization and World Health Organization guidelines and previous related studies. The food control index model was designed based on input and resources, interactions with stakeholders, science/knowledge base and continuous improvement, and control functions. The indicators are adjusted to the context of the food control system in Indonesia, including the dimension of interaction with stakeholders, which focuses on the national scope, because the model is prepared starting at the provincial level and forms an aggregate at the national level. This model is still in the initial stage of research and forms the basis for the preparation of subsequent instruments. The proposed conceptual framework could become the foundation needed for the development of the index, which can then be used as the basis for subsequent policy interventions to improve food security. Ultimately, this model could also increase food security and the competitiveness of food products in national and global markets.
查看更多>>摘要：The geographical origin of sea cucumber Apostichopus japonicas plays an important role in determining its market value. This study investigated the feasibility of using multi-element profile combined with explainable machine learning to trace the origin of sea cucumber in China. Multi-element profile (23 elements) of 167 sea cucumber samples was determined with ICP-OES and ICP-MS, and used for construction and evaluation of 4 ensemble learning models. Extreme gradient boosting (XGBoost) model achieved superior performance with an overall accuracy, precision, recall, F1 score and AUC as 0.95, 0.93, 0.91 and 1, respectively. The Shapley Additive Explanations (SHAP) algorithm was subsequently applied to interpret the XGBoost model output for desirable geographical information. Se was identified as the most important elemental marker for discriminating sea cu-cumber origins. Therefore, with clarified scientific support, multi-element profile combined with machine learning model could serve as a powerful tool for identifying the provenance of sea cucumber.
Caindec, Alyssa MarieJensen, Hanne AarslevHansen, Lisbeth TruelstrupKragh, Martin Laage...
8页
查看更多>>摘要：The historic view on low-moisture foods (LMFs) as safe due to the lack of microbial growth in these foods is challenged by an increasing number of reports of outbreaks and recalls caused by LMFs contaminated with foodborne pathogens. The objective of this study was to determine the survival of Salmonella Typhimurium, Bacillus cereus and Listeria monocytogenes on sliced Portobello mushrooms (Agaricus bisporus variant Portobello) during hot-air drying (mushroom internal temperature below 45 degrees C) for 8 h (h) in a small household food dehydrator (250 W) and subsequent storage of the vacuum-packed dried product for 2 months at room temperature. Hot-air drying reduced the water activity (aw) of the mushrooms to 0.17 +/- 0.03 well below the limit for microbial growth. S. Typhimurium and L. monocytogenes displayed total log CFU reductions of 2.5 +/- 0.4 and 2.6 +/- 0.8, respectively, while B. cereus exhibited significantly (p < 0.05) lower log reductions of 1.2 +/- 0.1. Storage of vacuum-packed dried mushrooms further reduced L. monocytogenes by 2 log CFU, while numbers of viable S. Typhimurium and B. cereus were not further reduced. The higher stability of S. Typhimurium and B. cereus were reflected in the number of reports in the European Rapid Alert System for Food and Feed system of the presence of these organisms in dried mushrooms. All three organisms regrew to high concentrations when dried mushrooms were soaked overnight at room temperature, simulating a scenario where mushrooms are improperly rehydrated. Combining results from hot-air drying and subsequent storage underlines that hot-air drying and prolonged storage at low aw cannot be relied on alone to reduce the microbial and pathogen load on Portobello mushroom.
查看更多>>摘要：Bacillus sporothermodurans is a producer of highly heat-resistant spores, which is a problem for the dairy industry worldwide. In this work, we studied the attachment and biofilm formation on stainless steel surfaces in contact with milk proteins (casein and whey). The results of the biofilm formation were obtained by the plate count method. In conjunction, biofilms (niches and cell sizes) were measured by scanning electron microscopy (SEM) on the 1st, 5th and 10th day. X-ray photoelectron spectroscopy (XPS) was a complementary technique that probed the conditioning of the substrate surface after 24 h. The milk proteins affected the total bacterial count in the samples, and also influenced the biofilm architecture. Sessile cell counts varied from 4.3 log CFU/cm2 in the attachment stage to up to 10.2 log CFU/cm2 in the matured biofilm stage. The spore counts varied from <1.4 +/- 0.02 (1st day) to 3.7 log +/- 1.1 log spores/cm2 (10th day). The control group at the biofilm maturation stage (5th day) had higher niches than at the cell fixation (1st day) and was different from the other groups that showed active dispersion in the presence of milk proteins. The same occurred on the 10th day for the control group. Circular patterns in the biofilm with casein, passive dispersal and elongated cells were also observed. Enzyme treatment and disinfectants may be used to remove or reduce biofilm formation.
NSTL
Elsevier