In vitro control of post-harvest fruit rot fungi by some plant essential oil components

Eight substances that are main components of the essential oils from three Mediterranean aromatic plants (Verbena officinalis, Thymus vulgaris and Origanum vulgare), previously found active against some phytopathogenic Fungi and Stramenopila, have been tested in vitro against five etiological agents of post-harvest fruit decay, Botrytis cinerea, Penicillium italicum, P. expansum, Phytophthora citrophthora and Rhizopus stolonifer. The tested compounds were β-fellandrene, β-pinene, camphene, carvacrol, citral, o-cymene, γ-terpinene and thymol. Citral exhibited a fungicidal action against P. citrophthora; carvacrol and thymol showed a fungistatic activity against P. citrophthora and R. stolonifer. Citral and carvacrol at 250 ppm, and thymol at 150 and 250 ppm stopped the growth of B. cinerea. Moreover, thymol showed fungistatic and fungicidal action against P. italicum. Finally, the mycelium growth of P. expansum was inhibited in the presence of 250 ppm of thymol and carvacrol. These results represent an important step toward the goal to use some essential oils or their components as natural preservatives for fruits and foodstuffs, due to their safety for consumer healthy and positive effect on shelf life extension of agricultural fresh products.     

Bioactivity of polycrystalline silicon layers

After oxygen, silicon is the second most abundant element in the environment and is present as an impurity in most materials. The widespread occurrence of siliceous biominerals as structural elements in lower plants and animals suggests that Si plays a role in the production and maintenance of connective tissue in higher organisms. It has been shown that the presence of Si is necessary in bones, cartilage and in the formation of connective tissue, as well as in some important metabolic processes. In this work, polycrystalline silicon layers are tested in terms of bioactivity, i.e., their ability to induce hydroxyapatite formation from simulated body fluid. Hydroxyapatite is a biologically compatible material with chemical similarity to the inorganic part of bones and teeth. Polycrystalline silicon layers are obtained by aluminum induced crystallization of Al and amorphous Si thin films deposited sequentially on glass substrates by radio-frequency magnetron sputtering and subsequently annealed in different atmospheres. The hydroxyapatite formation is induced by applying a method of laser-liquid-solid interaction. The method consists of irradiating the samples with laser light while immersed in a solution that is supersaturated with respect to Ca and P. As a result, heterogeneous porous sponge-like carbonate-containing hydroxyapatite is grown on the polysilicon surfaces. Crystals that are spherical in shape, containing Ca, P and O, Na, Cl, Mg, Al, Si and S, as well as well-faceted NaCl crystals are embedded in the hydroxyapatite layer. Enhancement of the hydroxyapatite growth and increased crystallinity is observed due to the applied laser-liquid-solid interaction.     

The effect of enzymatic treatment on blackcurrant (Ribes nigrum) juice flavour and its stability

The effects of different enzymatic treatments on the sensory profile and chemical composition, especially various phenolic compounds, sugars and fruit acids, of blackcurrant juices were investigated. In addition to pectinolytic activities, the enzymes had different cellulolytic, hemicellulolytic and glycolytic activities. The enzymatic treatments improved significantly the yield of juice, but with more fermented and astringent characteristics than juices without enzymatic hydrolysis. Enzymes with higher glycosidase activity increased astringency and the content of phenolic compounds in the juice. When the incubation temperature was elevated the contents of fruit acids increased whereas sugars and the perceived sweetness were the highest in the juices without enzymatic treatments. Despite of the significant changes in chemical composition, the sensory properties did not change significantly during 6 weeks of storage. Optimisation of the enzymatic process is crucial for juice making as maximising the juice yield or the content of phenolic compounds may produce unwanted sensory properties to the juice.     

Grape antioxidant dietary fiber stimulates Lactobacillus growth in rat cecum

The digesta is a highly active biological system where epithelial cells, microbiota, nondigestible dietary components, and a large number of metabolic products interact. The gut microbiota can be modulated by both endogenous and exogenous substrates. Undigested dietary residues are substrates for colonic microbiota and may influence gut microbial ecology. The objective of this work was to study the capacity of grape antioxidant dietary fiber (GADF), which is rich in polyphenols, to modify the bacterial profile in the cecum of rats. Male adult Wistar rats were fed for 4 wk with diets containing either cellulose or GADF as dietary fiber. The effect of GADF on bacterial growth was evaluated in vitro and on the cecal microbiota of rats using quantitative real time polymerase chain reaction (RT-PCR). The results showed that GADF intake stimulates proliferation of Lactobacillus and slightly affects the composition of Bifidobacterium species. GADF was also found to have a stimulative effect on Lactobacillus reuteri and Lactobacillus acidophilus in vitro. These findings suggest that the consumption of a diet rich in plant foods with high dietary fiber and polyphenol content may enhance the gastrointestinal health of the host through microbiota modulation. PRACTICAL APPLICATION: Grape antioxidant fiber combines nutritional and physiological properties of dietary fiber and natural antioxidants from grapes. Grape antioxidant fiber could be used as an ingredient for functional foods and as a dietary supplement to increase the intake of dietary fiber and bioactive compounds.     

Quantitative determination of octylphenol, nonylphenol, alkylphenol ethoxylates and alcohol ethoxylates by pressurized liquid extraction and liquid chromatography-mass spectrometry in soils treated with sewage sludges

Surfactants have one of the highest production rates of all organic chemicals. Non-ionic surfactants, especially alkylphenol ethoxylates, received most attention as precursors of estrogenic metabolic products generated during wastewater treatment. Alkylphenols (octyl and nonylphenol), alkylphenol polyethoxylates (APEOs), and alcohol ethoxylates (AEOs) have been determined in a Mediterranean forest soil (Mediterranean Rendzic Leptosol) amended with sludges from six waste water treatment plants (WWTPs) located in the Valencian Community. These compounds were isolated from soil by pressurized liquid extraction (PLE) using a mixture acetone-hexane (50:50 v/v), the extracts were cleaned up by solid-phase extraction (SPE) with C(18), and determined by liquid chromatography atmospheric pressure chemical ionization-mass spectrometry (LC-APCI-MS) using analytical standards for quantification. The method enabled high-reliable identification by monitoring the corresponding ammonium adduct [M+NH(3)](+) for AEOs and APEOs, and the deprotonated molecule [M-H](-) for octyl and nonylphenol. Recoveries, determined spiking soil samples at different concentrations, ranged from 89 to 94%, with limits of quantification from 1 to 100 microg kg(-1). Data obtained from a soil sample mixed with biosolids in the laboratory showed that these compounds are present at concentrations ranging from 0.02 to 5 mg kg(-1). According to these concentrations, levels of possible risk can be concluded for the presence of non-ionic surfactants in soil. However, further assessment will be necessary to establish the relationship between exposure and effect findings.     

Potential Therapeutic Application of Regulatory T Cells in Diabetes Mellitus Type 1

The autoimmune reaction against the beta cells of the pancreatic islets in type 1 diabetes mellitus (T1DM) patients is active in prediabetes and during the development of the clinical manifestation of T1DM, but it decreases within a few years of the clinical manifestation of this disease. A key role in the pathogenesis of T1DM is played by regulatory T cell (Treg) deficiency or dysfunction. Immune interventions, such as potential therapeutic applications or the induction of the Treg-cell population in T1DM, will be important in the development of new types of treatment. The aim of this study was to evaluate innovative immune interventions as treatments for T1DM. After an evaluation of full-length papers from the PubMed database from 2010 to 2021, 20 trials were included for the final analysis. The analysis led to the following conclusions: Treg cells play an important role in the limitation of the development of T1DM, the activation or application of Tregs may be more effective in the early stages of T1DM development, and the therapeutic use of Treg cells in T1DM is promising but requires long-term observation in a large group of patients.     

Metabolomic profiling of food matrices: Preliminary identification of potential markers of microbial contamination

The research aimed to generate an early warning system highlighting in real-time bacterial contamination of meat matrices and providing information which could support companies in accepting or rejecting batches. Current microorganisms’ detection methods rely on techniques (plate counting), which provide retrospective values for microbial contamination. The purpose of this research was to evaluate the ability of the headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC/MS) methodologies to detect volatile organic carbons (VOCs), which may be associated to a peculiar microbiological contamination of food. The disposal of fast headspace gas chromatography-mass spectrometry (HS-SPME-GC/MS) able to accurately and rapidly (30 min per sample) detect pathogens in raw meat could replace the traditional and time-consuming (3 to 4 days) standardized microbiological analysis required by regulations. Experiments focused on qualitative and quantitative evaluations of VOCs produced by Salmonella Typhimurium, Campylobacter jejuni, and Staphylococcus aureus in different types of raw meat (beef, pork, chicken). HS-SPME-GC/MS allowed to use smaller sample volumes compared to traditional methods with no sample processing and the potentiality for its application on various food matrices for the detection of a wide variety of pathogens. Data analysis showed the identification of unique VOCs’ profiles being possible markers of meat contamination due to their association to specific pathogens. The identification of VOCs markers in association to selected bacterial pathogens and their metabolites could support the rapid determination of specific meat samples contamination. Further research is required to outline-specific metabolic profiles for each microorganism responsible of meat contamination and prevent false positives.     

Characterization of acrylic resins and fluoroelastomer blends as potential materials in stone protection

Films of blends of Paraloid® B72 (copolymer of ethyl methacrylate and methyl acrylate) and Tecnoflon NM® (copolymer of vinylidene fluoride and hexafluoropropene) with different compositions were investigated by means of FT‐IR spectroscopy and FT‐IR microspectroscopy before and after UV and thermal treatments. Preliminary results of DSC measurements are also reported. Paraloid B72 has been extensively applied as a protective agent for stone since the 1950s. More recently considerable research has also been carried out on the application of fluorinated polymers in the field of stone conservation, eg the fluoroelastomer Tecnoflon®. A high content of Tecnoflon with respect to Paraloid increases the stability of the blends when they are submitted to UV radiation and thermal treatments. A THF solution of a blend of this kind was successfully applied to a marble surface of the Saint Maria Cathedral in Lucca, Tuscany, Italy. The changes in the properties of such mixtures with different compositions can offer new possibilities in developing suitable protective materials. © 2000 Society of Chemical Industry     

Assessment of the Photosynthetic Apparatus Functions by Chlorophyll Fluorescence and P700 Absorbance in C3 and C4 Plants under Physiological Conditions and under Salt Stress

Functions of the photosynthetic apparatus of C3 (Pisum sativum L.) and C4 (Zea mays L.) plants under physiological conditions and after treatment with different NaCl concentrations (0–200 mM) were investigated using chlorophyll a fluorescence (pulse-amplitude-modulated (PAM) and JIP test) and P₇₀₀ photooxidation measurement. Data revealed lower density of the photosynthetic structures (RC/CSo), larger relative size of the plastoquinone (PQ) pool (N) and higher electron transport capacity and photosynthetic rate (parameter R_Fd) in C4 than in C3 plants. Furthermore, the differences were observed between the two studied species in the parameters characterizing the possibility of reduction in the photosystem (PSI) end acceptors (REo/RC, REo/CSo and δRo). Data revealed that NaCl treatment caused a decrease in the density of the photosynthetic structures and relative size of the PQ pool as well as decrease in the electron transport to the PSI end electron acceptors and the probability of their reduction as well as an increase in the thermal dissipation. The effects were stronger in pea than in maize. The enhanced energy losses after high salt treatment in maize were mainly from the increase in the regulated energy losses (Φ_NPQ), while in pea from the increase in non-regulated energy losses (Φ_NO). The reduction in the electron transport from Q_A to the PSI end electron acceptors influenced PSI activity. Analysis of the P₇₀₀ photooxidation and its decay kinetics revealed an influence of two PSI populations in pea after treatment with 150 mM and 200 mM NaCl, while in maize the negligible changes were registered only at 200 mM NaCl. The experimental results clearly show less salt tolerance of pea than maize.     

Gene-Delivery Ability of New Hydrogenated and Partially Fluorinated Gemini bispyridinium Surfactants with Six Methylene Spacers

The pandemic emergency determined by the spreading worldwide of the SARS-CoV-2 virus has focused the scientific and economic efforts of the pharmaceutical industry and governments on the possibility to fight the virus by genetic immunization. The genetic material must be delivered inside the cells by means of vectors. Due to the risk of adverse or immunogenic reaction or replication connected with the more efficient viral vectors, non-viral vectors are in many cases considered as a preferred strategy for gene delivery into eukaryotic cells. This paper is devoted to the evaluation of the gene delivery ability of new synthesized gemini bis-pyridinium surfactants with six methylene spacers, both hydrogenated and fluorinated, in comparison with compounds with spacers of different lengths, previously studied. Results from MTT proliferation assay, electrophoresis mobility shift assay (EMSA), transient transfection assay tests and atomic force microscopy (AFM) imaging confirm that pyridinium gemini surfactants could be a valuable tool for gene delivery purposes, but their performance is highly dependent on the spacer length and strictly related to their structure in solution. All the fluorinated compounds are unable to transfect RD-4 cells, if used alone, but they are all able to deliver a plasmid carrying an enhanced green fluorescent protein (EGFP) expression cassette, when co-formulated with 1,2-dioleyl-sn-glycero-3-phosphoethanolamine (DOPE) in a 1:2 ratio. The fluorinated compounds with spacers formed by six (FGP6) and eight carbon atoms (FGP8) give rise to a very interesting gene delivery activity, greater to that of the commercial reagent, when formulated with DOPE. The hydrogenated compound GP16_6 is unable to sufficiently compact the DNA, as shown by AFM images.