Antibiofilm activity of LAE (ethyl lauroyl arginate) against food-borne fungi and its application in polystyrene surface coating

Several filamentous fungi species as Fusarium oxysporum or Cladosporium sp. can form biofilms by themselves or by participating in polymicrobial biofilms with bacteria. However, despite the high impact of biofilm on the food industry and the high efforts done to control biofilm produced by bacteria in the food area, there has been little study of strategies to control fungal biofilm in this area. In this study, the antibiofilm activity of the safe antimicrobial compound ethyl lauroyl arginate (LAE) was investigated against food spoilage fungi (Cladosporium cladosporioides, Aspergillus ochraceus, Penicillium italicum, Botrytis cynerea and Fusarium oxyspoum). Finally, the efficacy of a varnish-based coating incorporating LAE and coated onto polystyrene microtiter plates has been evaluated as a strategy to reduce fungal biofilm formation. The results of the 2,3-bis-(2-metoxi-4-nitro-5-sulfofenil)-2H-tetrazoilo-5-carboxanilida (XTT) assay, which measure the biofilm metabolic activity of moulds, demonstrated that LAE reduced significantly the formation of fungal biofilm at concentrations from 6 to 25 mg/L. This reduction was confirmed by the micrographs obtained by scanning electronic microscopy (SEM). In addition, LAE also showed antifungal activity against established biofilms. Particularly, it reduced their metabolic activity and viability at concentrations from 6 to 25 mg/L according to results obtained in the XTT assay and observations made by confocal laser scanning microscopy (CLSM). Finally, active coating incorporating from 2% of LAE proved to reduce significantly the biofilm formation in C. cladosporioides, B. cynerea and F. oxyspoum according to the results obtained in the XTT assay. However, the released studies indicated that the retention of LAE in the coating should be improved to prolong their activity

Prediction of collision cross section values: application to non-intentionally added substance identification in food contact materials

The synthetic chemicals in food contact materials can migrate into food and endanger human health. In this study, the traveling wave collision cross section in nitrogen values of more than 400 chemicals in food contact materials were experimentally derived by traveling wave ion mobility spectrometry. A support vector machine-based collision cross section (CCS) prediction model was developed based on CCS values of food contact chemicals and a series of molecular descriptors. More than 92% of protonated and 81% of sodiated adducts showed a relative deviation below 5%. Median relative errors for protonated and sodiated molecules were 1.50 and 1.82%, respectively. The model was then applied to the structural annotation of oligomers migrating from polyamide adhesives. The identification confidence of 11 oligomers was improved by the direct comparison of the experimental data with the predicted CCS values. Finally, the challenges and opportunities of current machine-learning models on CCS prediction were also discussed. © 2022 The Authors. Published by American Chemical Society

New active antioxidant multilayer food packaging films containing Algerian Sage and Bay leaves extracts and their application for oxidative stability of fried potatoes

The antioxidant activity of Sage leaf (SL) and Bay leaf (BL) extracts was studied. Both plants were extracted using water and ethanol at different concentration, and the antioxidant activity was measured by ABTS [2, 2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)] radical cation scavenging and reducing power (RP) methods. In both cases 60% and 80% ethanolic extracts of Sage and Bay leaves showed the highest activity and were incorporated into multilayer films. The initial concentration for 60% ethanolic extracts of Sage and Bay leaves to scavenge 50% of free radical ABTS were 5.67 ± 0.26 µg × mL-1 and 18.68 ± 0.16 µg × mL-1 respectively, whereas for 80% ethanolic extracts the concentrations were 7.96 ± 0.02 and 14.65 ± 0.59 µg × mL-1 respectively. The initial concentrations of ethanolic 60% extracts of Sage and Bay leaves to allow absorbance 0.5 for reducing power were 35.38 ± 0.19 µg × mL-1 and 91.43 ± 2.84 µg × mL-1 respectively, while for 80% ethanolic extracts of Bay and Sage leaves were 46.01 ± 1.21 µg × mL-1 and 85.47 ± 0.9 µg × mL-1 respectively. Then, the multilayer films were exposed to a gas stream enriched with free radicals to evaluate the free radicals scavenging. The new packaging with 60% ethanolic Sage extract exhibited the highest activity with low percentage of hydroxylation (69.64 ± 6.86%) followed by that with 80% ethanolic extract for both Bay (85.49 ± 5.3%) and Sage (87.09 ± 3.93%) leaves extracts. The ability of two active packaging built with 60% ethanolic Sage extract and 80% ethanolic Bay extract to inhibit lipid oxidation of fried potatoes was studied by measuring secondary lipid oxidation products using thiobarituric acid reactive substances (TBARS). Significant lower value of Malondialdehyde (MDA) was obtained for fried potatoes stored in active packaging built with ethanolic 60% extract of Sage and 80% ethanolic extract of Bay leaves (0.342 ± 0.01 and 0.392 ± 0.02 µg MDA × g-1 respectively) at 40 °C for 20 days compared to the control (0.568 ± 0.03 µg MDA × g-1). Lipid oxidation decreased 40% and 31% for packaging with 60% Sage and 80% Bay ethanolic extracts respectively. The UPLC–MS–QTOF analysis of Sage and Bay leaves extracts revealed the presence of phenolic acids, tannins, flavonoids, and terpenoids. Migration tests from active materials demonstrated the absence of migration

Polylactide-based films with the addition of poly(ethylene glycol) and extract of propolis—physico-chemical and storage properties

Polymeric films based on polylactide (PLA) with the addition of poly(ethylene glycol) (PEG) and a chloroformic extract of propolis were obtained. In the case of the studied films, polylactide (PLA) played the role of polymeric matrix and poly(ethylene glycol) was used as a plasticizer, while the extract of propolis was incorporated as a compound that could significantly affect the properties of the obtained materials, especially the water vapour permeation rate and the stability of the food products. Moreover, changes in structure, morphology, mechanical and storage properties as well as differences in colour, thickness and transparency after introducing propolis into the PLA–PEG system were determined. Based on the obtained results, it was established that the addition of the chloroformic extract of propolis significantly influences the most important properties taken into account during food packaging. It was also noticed that films with incorporated propolis were characterised by a significant improvement in the water vapour barrier property. Moreover, the obtained results prove that packaging containing a chloroformic propolis extract allow for the maintenance of the quality of the fruit stored for an extended period of time. To summarise, the application of a chloroformic propolis extract enables the formation of packaging materials that extend the shelf life of stored food products

Compounds from multilayer plastic bags cause reproductive failures in artificial insemination

High levels of reproductive failure were detected in some Spanish sow farms in the Spring of 2010. Regular returns to estrus and variable reductions in litter size were observed. The problem started suddenly and did not appear to be related to the quality of the ejaculates, disease, alterations of body condition or any other apparent reasons. Subsequent studies determined that the problem was the origin of the plastic bags used for semen storage. Chemical analysis of the suspicious bags identified unexpected compounds such as BADGE, a cyclic lactone and an unknown phthalate that leached into the semen at concentrations of 0.2 to 2.5 mg/L. Spermatozoa preserved in these bags passed all of the routine quality control tests, and no differences were observed between storage in the control and suspicious bags (p . 0.05). In vitro fecundation tests and endocrine profiler panel analysis (EPP) did not show any alterations, whereas the in vivo tests confirmed the described failure. This is the first described relationship between reproductive failure and toxic compounds released from plastic bags

Sample preparation procedure for the determination of polycyclic aromatic hydrocarbons in petroleum vacuum residue and bitumen

This paper describes a novel method of sample preparation for the determination of trace concentrations of polycyclic aromatic hydrocarbons (PAHs) in high-boiling petroleum products. Limits of quantitation of the investigated PAHs in materials of this type range from tens of nanograms per kilogram to <20 μg/kg. The studies revealed that in order to separate most of interferences from the analytes without a significant loss of PAHs, it is necessary to use size exclusion chromatography as the first step of sample preparation, followed by adsorption using normal-phase liquid chromatography. The use of orthogonal separation procedure described in the paper allows the isolation of only a group of unsubstituted and substituted aromatic hydrocarbons with a specific range of molar mass. The lower the required limit of quantitation of PAHs, the larger is the scale of preparative liquid chromatography in both steps of sample preparation needed. The use of internal standard allows quantitative results to be corrected for the degree of recovery of PAHs during the sample preparation step. Final determination can be carried out using HPLC-FLD, GC-MS, or HPLC-UV–VIS/DAD. The last technique provides a degree of identification through the acquired UV–VIS spectra

Elucidating the significance of copper and nitrate speciation in Cu-SSZ-13 for N2O formation during NH3-SCR

Unwanted N2O formation is a problem that has been noted in selective catalytic reduction (SCR) where copper zeolite catalysts are utilized. With its immense global warming potential and long-term stability, elevated atmospheric N2O has already been identified as a future challenge in the war on climate change. This paper explores the phenomenon of N2O formation during NH3-SCR over Cu-SSZ-13 catalysts, which are currently commercialized in automotive emissions control systems, and proposes a link between N2O production and the local copper environment found within the zeolite. To achieve this, a comparison is made between two Cu-SSZ-13 samples with different copper co-ordinations produced via different synthesis methods. A combination of synchrotron X-ray absorption near-edge spectroscopy, UV–vis, Raman, and density functional theory (DFT) is used to characterize the nature of copper species present within each sample. Synchrotron IR microspectroscopy is then used to compare their behavior during SCR under operando conditions and monitor the evolution of nitrate intermediates, which, along with further DFT, informs a mechanistic model for nitrate decomposition pathways. Increased N2O production is seen in the Cu-SSZ-13 sample postulated to contain a linear Cu species, providing an important correlation between the catalytic behavior of Cu-zeolites and the nature of their metal ion loading and speciation