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In this study, growth‐dependent changes in the mechanical properties of the tomato (Solanum lycopersicum) cuticle during fruit development were investigated in two cultivars with different patterns of cuticle growth and accumulation. The mechanical properties were determined in uniaxial tensile tests using strips of isolated cuticles. Changes in the functional groups of the cuticle chemical components were analysed by attenuated total reflectance–Fourier transform infrared (ATR‐FTIR). The early stages of fruit growth are characterized by an elastic cuticle, and viscoelastic behaviour only appeared at the beginning of cell enlargement. Changes in the cutin:polysaccharide ratio during development affected the strength required to achieve viscoelastic deformation. The increase in stiffness and decrease in extensibility during ripening, related to flavonoid accumulation, were accompanied by an increase in cutin depolymerization as a result of a reduction in the overall number of ester bonds. Quantitative changes in cuticle components influence the elastic/viscoelastic behaviour of the cuticle. The cutin:polysaccharide ratio modulates the stress required to permanently deform the cuticle and allow cell enlargement. Flavonoids stiffen the elastic phase and reduce permanent viscoelastic deformation. Ripening is accompanied by a chemical cleavage of cutin ester bonds. An infrared (IR) band related to phenolic accumulation can be used to monitor changes in the cutin esterification index.

Fourier transform infrared (FTIR) is a spectroscopy technique widely used to identify organic materials. It has recently gained popularity in microplastic (MP) pollution research to determine the chemical composition of unknown plastic fragments. However, it could also be used to evaluate the degree of ageing of MPs collected from the environment. In this context, the principal aim of our research has been to qualitatively evaluate the natural weathering of environmental MPs collected in an Italian freshwater body (the Ofanto River) using ATR-FTIR technology. Furthermore, we compared environmental particles to weathered artificial MPs under controlled light and temperature conditions and to unaltered pristine materials to assess the results. FTIR spectra were acquired using a Nicolet Summit FTIR (ThermoFisher Scientific) equipped with an Everest ATR with a diamond Crystal plate and a DTGS KBr detector (wavenumber range 4000–500 cm−1, 32 scans per spectrum, spectral resolution of 4 cm−1). The degree of ageing was assessed using three different indexes known to be related to changes in MPs: Carbonyl Index (CI), Hydroxyl Index (HI), and Carbon-Oxygen Index (COI). The overall results showed that the regions reflecting changes (hydroxyl groups, peaks from 3100 to 3700 cm−1, alkenes or carbon double bonds, 1600 and 1680 cm−1, and carbonyl groups, 1690 and 1810 cm−1) appeared significantly modified in artificial and natural weathered particles compared to the pristine materials. The indexes calculated for polymers degraded under the artificial photo and thermo ageing conditions displayed a general tendency to increase with the time in contact with irradiation time. Particular enhancements of CI of PS fragment and PE pellet, HI of PE and PS fragments and PE pellet, and COI of PS fragment were observed. Otherwise, the following incubation of the same particles at a constant temperature of 45 °C did not further affect the chemical composition of the particles. Moreover, new unique peaks were also observed in the freshwater particles, almost all in the fingerprint region (1500–500 cm−1). Differences in CI, HI, and COI were evidenced among the different morphological MP shapes. On the one hand, the CI calculated for the environmental PE pellets showed values ranging from 0.05 to 0.26 with a mean value of 0.17 ± 0.10. Most samples (57%) presented a CI with values between 0.16 and 0.30. On the other hand, fragments presented slicer modifications in the carbonyl region with CI values lower than pellets (0.05 ± 0.05). This index helps evaluate the degradation of PE MPs by UV light, increasing with enhancing residence time in the environment. Conversely, fragments showed greater values of HI (5.90 ± 2.57) and COI (1.04 ± 0.48) than pellets, as well as lines, which presented the maximum value of HI (11.51). HI is attributed to the bond vibrations of hydroxyl, carboxyl, or phenol groups. In contrast, COI is frequently attributed to the vibrations of C_O bonds found in carbohydrates, alkanes, secondary alcohols, and ketones. In conclusion, our results showed characteristics spectra acquired from environmental particles compared to pristine and artificial aged ones. The interpretation of our main results emphasizes the need to conduct ecotoxicological experimental studies using naturally weathered particles due to the unicity of their properties, which are more helpful for understanding microplastic pollution effects.

Veterinary drugs in milk poses a risk to consumers’ health. Little attention is paid to investigating residues of veterinary medicines in powdered milk, then there is a need to develop new methods for monitoring these residues. We proposed the use of random forest (RF) for the prediction of the concentration of ivermectin residues in freeze-dried milk, using FTIR spectroscopy. Eight hundred models were tested and after fine tuning the best RF model was obtained with 800 trees, 5 variables for each tree, node size 1, and 75% of the data for training. The RF regression model demonstrated good ability to predict the concentration of ivermectin residues in freeze-dried milk, with correlation and determination coefficients greater than 0.96 and low error and residual values (approximately 1.0). The proposed method is fast, simple, sensitive, low cost, non-destructive and environmentally friendly, being an alternative to make the control of ivermectin residues in milk. RESUMO: Medicamentos veterinários no leite representam riscos à saúde dos consumidores. Pouca atenção é dada à investigação de resíduos de medicamentos veterinários em leite em pó, havendo, portanto, a necessidade do desenvolvimento de novos métodos para monitorar esses resíduos. Propomos o uso de Randon Forest (RF) para a predição da concentração de resíduos de ivermectina em leite em liofilizado, utilizando a espectroscopia FTIR. Foram testados 800 modelos e, após ajustes finos, o melhor modelo RF foi obtido com 800 árvores, cinco variáveis para cada árvore, tamanho de nó 1 e 75% dos dados para treinamento. O modelo de regressão RF demonstrou boa capacidade de prever a concentração de resíduos de ivermectina em leite liofilizado, com coeficientes de correlação e determinação superiores a 0,96 e baixos valores de erro e resíduos (aproximadamente 1,0). O método proposto é rápido, simples, sensível, de baixo custo, não destrutivo e ambientalmente amigável, sendo uma alternativa para o controle de resíduos de ivermectina no leite.

Electrochemical CO2 reduction reaction (CO2RR) to produce value‐added multi‐carbon chemicals has been an appealing approach to achieving environmentally friendly carbon neutrality in recent years. Despite extensive research focusing on the use of CO2 to produce high‐value chemicals like high‐energy‐density hydrocarbons, there have been few reports on the production of propane (C3H8), which requires carbon chain elongation and protonation. A rationally designed 0D/2D hybrid Cu2O anchored‐Ti3C2Tx MXene catalyst (Cu2O/MXene) is demonstrated with efficient CO2RR activity in an aqueous electrolyte to produce C3H8. As a result, a significantly high Faradaic efficiency (FE) of 3.3% is achieved for the synthesis of C3H8 via the CO2RR with Cu2O/MXene, which is ≈26 times higher than that of Cu/MXene prepared by the same hydrothermal process without NH4OH solution. Based on in‐situ attenuated total reflection‐Fourier transform infrared spectroscopy (ATR‐FTIR) and density functional theory (DFT) calculations, it is proposed that the significant electrocatalytic conversion originated from the synergistic behavior of the Cu2O nanoparticles, which bound the *C2 intermediates, and the MXene that bound the *CO coupling to the C3 intermediate. The results disclose that the rationally designed MXene‐based hybrid catalyst facilitates multi‐carbon coupling as well as protonation, thereby manipulating the CO2RR pathway. A rational design of Cu2O/Ti3C2Tx MXene catalyst presents an excellent activity for saturated hydrocarbon C3H8 from electrochemical CO2 reduction, providing *C2‐*C1 coupling sites and facilitating further protonation. Based on in‐situ attenuated total reflection‐Fourier transform infrared spectroscopy and density functional theory calculations, results offer insights into green electrochemical carbon utilization for achieving carbon neutrality as well as lowering global warming potential.

In recent years, many studies on the analysis of microplastics (MP) in environmental samples have been published. These studies are hardly comparable due to different sampling, sample preparation, as well as identification and quantification techniques. Here, MP identification is one of the crucial pitfalls. Visual identification approaches using morphological criteria alone often lead to significant errors, being especially true for MP fibers. Reliable, chemical structure-based identification methods are indispensable. In this context, the frequently used vibrational spectroscopic techniques but also thermoanalytical methods are established. However, no critical comparison of these fundamentally different approaches has ever been carried out with regard to analyzing MP in environmental samples. In this blind study, we investigated 27 single MP particles and fibers of unknown material isolated from river sediments. Successively micro-attenuated total reflection Fourier transform infrared spectroscopy (μ-ATR-FTIR) and pyrolysis gas chromatography-mass spectrometry (py-GCMS) in combination with thermochemolysis were applied. Both methods differentiated between plastic vs. non-plastic in the same way in 26 cases, with 19 particles and fibers (22 after re-evaluation) identified as the same polymer type. To illustrate the different approaches and emphasize the complementarity of their information content, we exemplarily provide a detailed comparison of four particles and three fibers and a critical discussion of advantages and disadvantages of both methods.

A series of chemical and biochemical parameters of edible hemp resources (seeds, oil, and flour) from the monoecious EU registered hemp genotype Fedora, was determined, including fatty acid profile, phytosterol composition, total phenolics, antioxidant activity, macro- and micro-elements. The fatty acid ω-3/ω-6 approached the nutritionally optimal 3/1 ratio. β-sitosterol and other phytosterols sterols dominated the unsaponifiable fraction. Hemp seeds, flour, and oil contained 767 ± 41, 744 ± 29, and 21 ± 5 mg GAE kg−1 total polyphenols, respectively. The antioxidant potential of Fedora flour and seeds, evaluated through the DPPH (2,2-Diphenyl-1-picrylhydrazyl) assay, was higher than that of oil. K and Mg were the most abundant macro-elements, particularly in flour, while the concentration of trace elements was Fe > Cu > Ni > Mn. The presence of an array of bioactive compound candidate Fedora products as health-promoting food matrices. The ATR-FTIR spectra of hemp-derived products indicated the proximate composition of macro-nutrients.

With climate change, pea will be more frequently subjected to heat stress in semi-arid regions like Saskatchewan during flowering. The pollen germination percentage of two pea cultivars was reduced by heat stress (36°C) with an important decrease in cultivar 'CDC Golden' compared to 'CDC Sage.' Lipids, protein and other pollen coat compositions of whole intact pollen grains of both pea cultivars were investigated using mid infrared (mid-IR) attenuated total reflectance (ATR)-Fourier transform infrared (FTIR) spectroscopy. Curve fitting of ATR absorbance spectra in the protein region enabled estimation and comparison of different protein secondary structures between the two cultivars. CDC Sage had relatively greater amounts of α-helical structures (48.6-43.6%; band at 1654 cm(-1)) and smaller amounts of β-sheets (41.3-46%) than CDC Golden. The CDC Golden had higher amounts of β-sheets (46.3-51.7%) compared to α-helical structures (35.3-36.2%). Further, heat stress resulted in prominent changes in the symmetrical and asymmetrical CH2 bands from lipid acyl chain, ester carbonyl band, and carbohydrate region. The intensity of asymmetric and symmetric CH2 vibration of heat stressed CDC Golden was reduced considerably in comparison to the control and the decrease was higher compared to CDC Sage. In addition, CDC Golden showed an increase in intensity at the oxidative band of 3015 cm(-1). These results reveal that the whole pollen grains of both pea cultivars responded differently to heat stress. The tolerance of CDC Sage to heat stress (expressed as pollen germination percentage) may be due to its protein richness with α-helical structures which would protect against the destructive effects of dehydration due to heat stress. The low pollen germination percentage of CDC Golden after heat stress may be also due to its sensitivity to lipid changes due to heat stress.

Two methods—attenuated total reflection Fourier infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS)—have been used to analyze the chemical structure of polytetrafluorethylene (PTFE) thin coatings deposited by pulsed laser (PLD) and pulsed electron beam (PED) ablations. The volume of the analyzed materials is significantly different in these techniques which can be of great importance in the characterization of highly heterogeneous thin films. Optical microscopy, atomic force microscopy (AFM) and scanning electron microscopy (SEM) have been additionally used to examine the coating surface morphology. The studies have shown that in the case of thin polymer coatings deposited by physical methods, the application for chemical structure evaluation of complementary techniques, with different surface sensitivity, together with the use of surface topography imaging, provide unique insight into the film morphology. The results can provide information contributing to an in-depth understanding of the deposition mechanism of polymer coatings.

The researches on MPs in commercial marine fish are very limited although in marine environments microplastic (MPs) pollution is a global problem. In this study, the presence, composition, and characterization of MPs in different tissues (brain, gill, muscle, and gastrointestinal tract) of commercial fish species [red mullet (Mullus barbatus) and pontic shad (Alosa immaculata Bennett 1835)] from the Black Sea were investigated. M. barbatus (demersal) and A. immaculata (pelagic) fish were preferred in the selection of fish species in order to represent demersal and pelagic environments. After dissected the fish, MPs were obtained from the tissues by extraction using the flotation method; then the MPs were counted and categorized according to shape, size, and color. The composition of the MPs was determined via ATR–FTIR spectroscopy. In terms of microplastic abundance in fish tissues, the gastrointestinal tract (40.0%) ranked first in both fish species, while the lowest MPs density was determined in brain tissues (7.0%). After the gastrointestinal tissue, gills were identified as the second tissue with the highest MPs density. Regardless of fish species, MPs characterization was mainly fibrous (51.0%), black colored (49.0%), and 50–200 µm in size (55.0%). Among the nine different polymers determined, polychloroprene (18.8%) and polyamide (15.0%) were found most frequently. This research provides data for tissue-based assessment of MPs in fish. The obtained data showed that MPs (one of the anthropogenic pollutants) are quite high in all tissues regardless of fish species. Moreover, it has emerged that these two fish species are suitable for monitoring microplastics in the study area.

Dewatered digested sludge and compost may act as a conduit for microplastics (<5 mm) in terrestrial and subsequently aquatic systems. However, standardized methods for microplastics analyses are lacking. Thus, the aim is to demonstrate the applicability of wet-sieving as a way to quantify large microplastic particles (MPP, 1–5 mm) in dewatered digested sludge and compost. Additionally, we investigated the organic fraction of municipal solid waste, expired drinks and slaughterhouse waste used as co-substrate for anaerobic digestion at wastewater treatment plants (WWTP). Therefore, we collected samples from six WWTP and two biogas plants. These were then wet-sieved and potential MPP analysed via attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). In dewatered digested sludge the amount of microplastics ranged from 0 to 326 MPP/kg TS (total solids) while compost contained 39–102 MPP/kg TS. Our results show that with 0–36 MPP/kg TS co-substrates are not necessarily a source of microplastics in WWTP. Furthermore, we found film to be the most abundant shape in the biogas plant samples, whereas, in WWTP samples film, fragments and fibers were detected the most. ATR-FTIR revealed that polyvinyl chloride, polyester, polypropylene, and polyethylene were the most abundant materials found across all samples. HIGHLIGHTS Standardized methods for MP analysis are still lacking. Applicability of wet-sieving as method of detection for MP of 1–5 mm is demonstrated. It is proposed that the number of MPP should always be given in reference to the total solids of the respective sample. More research is needed to evaluate the effect of co-substrates on the number of MPP in WWTPs.