1,721,004 research outputs found
Sulfur deprivation results in oxidative perturbation in chlorella sorokiniana (211/8k)
Get PDFSulfur deficiency in plant cells has not been considered as a potential abiotic factor that can induce oxidative stress. We studied the antioxidant defense system of Chlorella sorokiniana cultured under sulfur (S) deficiency, imposed for a maximum period of 24 h, to evaluate the effect of an S shortage on oxidative stress. S deprivation induced an immediate (30 min) but transient increase in the intracellular H2O2 content, which suggests that S limitation can lead to a temporary redox disturbance. After 24 h, S deficiency in Chlorella cells decreased the glutathione content to <10% of the value measured in cells that were not subjected to S deprivation. Consequently, we assumed that the cellular antioxidative mechanisms could be altered by a decrease in the total glutathione content. The total ascorbate pool increased within 2 h after the initiation of S depletion, and remained high until 6 h; however, ascorbate regeneration was inhibited under limited S conditions, indicated by a significant decrease in the ascorbate/dehydroascorbate (AsA/DHA) ratios. Furthermore, ascorbate peroxidase (APX) and superoxide dismutase (SOD) were activated under S deficiency, but we assumed that these enzymes were involved in maintaining the cellular H2O2 balance for at least 4 h after the initiation of S starvation. We concluded that S deprivation triggers redox changes and induces antioxidant enzyme activities in Chlorella cells. The accumulation of total ascorbate, changes in the reduced glutathione/oxidized glutathione (GSH/GSSG) ratios and an increase in the activity of SOD and APX enzymes indicate that oxidative perturbation occurs during S deprivation
Biodegradation of Juglone by Xanthomonas arboricola pv. juglandis, The Causal Agent of Walnut (Juglans regia L.) Bacterial Blight
No full text: Xanthomonas arboricola pv. juglandis is the causal agent of walnut blight, a disease affecting Juglans regia L. cultivations by causing severe economic losses worldwide. The content of phenolic compounds in J. regia cultivars plays an important role in determining the resistance or susceptibility to the infection. In this study, the assessment of antimicrobial activity against several phytopathogenic Xanthomonas arboricola and Pseudomonas strains, revealed that X. a. pv. juglandis was less susceptible to juglone at higher concentrations, suggesting a potential resistance mechanism. In order to explore the antibacterial results, the biodegradation of juglone in the presence of X. a. pvs. juglandis and pruni was assessed at three different collecting times by NMR. The NMR analysis clearly showed the ability of X. a pv. juglandis NCPPB1659 to degrade juglone. On the contrary, X. arboricola pv. pruni NCPPB2588 was ineffective. The seasonal variation of juglone collected in leaves and husks of walnuts was determined
Metal-organic frameworks for food applications: A review
No full textMetal-organic frameworks (MOFs) are high surface-to-volume ratio crystalline hybrid porous coordination materials composed of metal ions as nodes and organic linkers. The goal of this paper was to provide an updated and comprehensive state-of-the-art review of MOFs for different food applications such as active food contact materials, antimicrobial nanocarriers, controlled release nanosystems for active compounds, nanofillers for food packaging materials, food nanoreactors, food substance nanosensors, stabilizers and immobilizers for active compounds and enzymes, and extractors of food contaminants. Extraction and sensing of several food contaminants have been the main food applications of MOFs. The other applications listed above require further investigation, as they are at an early stage. However, interesting results are being reported for these other fields. Finally, an important limitation of MOFs has been the use of non-renewable feedstocks for their synthesis, but this has recently been solved through the manufacture and use of γ-cyclodextrin-based MOFs.Fil: Magri, Anna. Council For Agricultural Research And Economics; ItaliaFil: Petriccione, Milena. Council For Agricultural Research And Economics; ItaliaFil: Gutiérrez Carmona, Tomy José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin
Essential Oils in Postharvest Treatment against Microbial Spoilage of the Rosaceae Family Fruits
No full textFruits undergo numerous chemical, physical, and microbiological changes during storage that shorten their postharvest life, reducing shelf-life and boosting food loss. Food quality and safety are seriously threatened by postharvest infections, one of the factors behind postharvest deterioration and mycotoxin contamination in fruits. The control of postharvest deterioration is a big concern because there are few management methods available. Several attempts have been undertaken to prevent the microbial degradation of fresh food at the postharvest stage without using synthetic fungicides, which are dangerous for the environment and people’s health. A good substitute for synthetic fungicides among them is the use of natural plant compounds, such as essential oils included or not included in the edible coatings. This review’s aim was to collect information from the scientific literature on the biological activity of essential oil, with or without edible coatings, against pathogens that cause the postharvest spoilage of many fruit belonging to Rosaceae family in order to develop appropriate substitute tactics for synthetic fungicides in the treatment of postharvest fruit diseases. Advances and obstacles surrounding emerging methods that may be useful for enhancing the effectiveness and dependability of essential oils were evaluated
Clarification of morphological traits of unexplored ‘Mortarella’ and ‘Camponica’ hazelnut cvs. From the Campania region of Italy, to enhance their shell polyphenol diversity
No full textEuropean hazelnuts are widely cultivated as raw materials in the food industry. Processing produces several non-value-added byproducts, e.g. pericarp and episperm. Herein, the ‘Camponica’ and ‘Mortarella’ cultivars were characterised using International Union for the Protection of New Varieties of Plants guidelines. The in-depth analysis of the chemical profiles of different particle size sieved fractions from hazelnut outer pericarps was performed following ultrasound-assisted extraction and ultra-high-performance liquid chromatography-high-resolution mass spectrometry (UHPLC-HRMS). Total phenolic, flavonoid, and tannin contents were evaluated, as well as their radical scavenging capacity using 2,2-diphenyl-1-picrylhydrazyl and 2,2-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid assays. The outer shell extracts mainly contained ellagic acid derivatives, giffonins, and flavonol glycosides. The inner pericarp and episperm differed for their exclusive epicatechin, catechin, and proanthocyanidin dimer content. The novel data provide new insights into the differences in the chemical compositions of byproducts of these hazelnut cultivars, which will be valuable for nutraceutical, cosmetic, and functional food valorisation applications
An ELISA method to identify the phytotoxic Pseudomonas syringae pv. actinidiae exopolysaccharides: A tool for rapid immunochemical detection of kiwifruit bacterial canker
No full textThe phytotoxic exopolysaccharides produced by Pseudomonas syringae pv. actinidiae, the causal agent of bacterial canker of kiwifruit, were isolated and partially identified. Their phytotoxic activity was evaluated on host and non-host plants and their role in the complex mechanisms of host-pathogen interaction was also discussed. The phytotoxic exopolysaccharides, which are natural antigens, were used to arise specific antibodies by rat immunization. The antibodies were used to develop a rapid and specific method to unambiguously detect P.s. pv. actinidiae exopolysaccharides isolated from bacterial culture and infected plant samples. Indeed, the antibodies recognized the exopolysaccharides produced by other two strains of P. s. pv. actinidiae but did not cross reacted with those isolated from P. s. pv. syringae and Pseudomonas viridiflava culture filtrates. Finally, the same antibodies significantly recognized the exopolysaccharides extracted from infected kiwi leaves
Procedimento per la conservazione di prodotti lievitati
No full textLa presente invenzione riguarda in generale il campo della conservazione di prodotti alimentari e, più precisamente, si riferisce ad un metodo per la conservazione in atmosfera modificata di prodotti da forno o lievitati, sia crudi che cotti
Polyphenols from Olea europaea L. cv. Caiazzana leaf pruning waste for antioxidant and UV-blocking starch-based plastic films
No full textOlive tree waste products, such as leaves, can be used to formulate antioxidant additive mixtures for bioactive and functional packaging. In this context, with the aim of better enhancing the flavonoid component, the extract obtained by ultrasonic accelerated maceration was fractionated to obtain the OlP fraction, characterized by UltraViolet-Visible (UV-Vis) and Attenuated Total Reflectance Fourier Transform InfraRed (ATR FT-IR) spectroscopic techniques and chromatographic analysis coupled to high-resolution tandem mass spectrometry. The extract, consisting of 60.4 % flavonoids, exhibited a marked antiradical capacity but did not exert cytotoxic effects. The incorporation, at two different percentage levels, in a starch-based film, already with the plasticizers glycerol and sorbitol, was previously characterized chemically by ATR FT-IR tools, morphologically by Scanning Electron Microscopy (SEM), for the thermal behaviour and physical-chemical properties of thickness, density, water vapor transmission rate, moisture absorption, and colour. The data obtained, including the assessment of the UV-blocking, photoprotective, and antiradical activities, emphasize that the composition of the film was maintained, with OlP preserving its antioxidant efficacy while also acting more effectively as a moisture absorber and natural plasticizer
Molecular sieves for food applications: A review
No full textBackground: Molecular sieves are materials with selective sorption properties, and are used to separate or load mixtures of compounds based on their molecular shape and size. These materials are usually made from porous materials and molecularly imprinted polymers (MIPs). Scope and approach: Although molecular matrices can be manufactured from either inorganic porous materials or MIPs, the former have been used more widely in the different fields of science and technology. Specifically, MIPs have been little studied as molecular sieves for food applications, as they have only very recently been introduced materials in this field. For this reason, in this review we focus on molecular sieves prepared from porous materials. Key findings and conclusions: Molecular matrices have been mainly used as materials for food packaging, food nanoreactors, the absorption of pathogens, the controlled and sustained release of active compounds and enzymes, the stabilization and immobilization of active substances and enzymes, the detection and removal of food contaminants, and in the development of intelligent food contact materials. All these aspects are extensively reviewed in this manuscript, with particular emphasis on the literature published during the last five years.Fil: Villa, Cristian C.. Universidad del Quindio; ColombiaFil: Galus, Sabina. Warsaw University Of Life Sciences; PoloniaFil: Nowacka, Małgorzata. Warsaw University Of Life Sciences; PoloniaFil: Magri, Anna. No especifíca;Fil: Petriccione, Milena. No especifíca;Fil: Gutiérrez Carmona, Tomy José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin
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