120 research outputs found

    Extrusion-Cooking of Starch

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    Profile of Phenolic Acids and Antioxidant Capacity in Organs of Common Buckwheat Sprout

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    The aim of the study was to analyse the content of phenolic acids, total phenolic compounds, proanthocyanidins, and antioxidant capacity in cotyledons and hypocotyl of five cultivars of common buckwheat (Fagopyrum esculentum Moench) sprout. This study presents the first broad profile of phenolic acids occurring in buckwheat microgreen seedlings. In the hypocotyl and cotyledons trans-cinnamic acid and its derivatives: o-, m-, and p-coumaric acids (2-, 3-, and 4-hydroxycinnamic), synapic acid (4-hydroxy-3,5-dimethoxycinnamic), caffeic acid (3,4-dihydroxycinnamic), and two isomers of ferulic acid (4-hydroxy-3-methoxycinnamic and 3-hydroxy-4-methoxycinnamic) have been identified. Among the benzoic acid derivatives hydroxybenzoic, protocatechuic (3,4-dihydroxybenzoic), gallic (3,4,5-dihydroxybenzoic) and syringic (4-hydroxy-3,5-dimethoxybenzoic) were found in the organs. In addition to those mentioned, the organs of buckwheat sprouts contain chlorogenic acid as well. The contents of all analysed phenolics were substantially higher in the cotyledons than in the hypocotyl of buckwheat sprouts, except for chlorogenic and caffeic acids. Trans-cinnamic acid was the major phenolic acid in both organs. In the cotyledons, a significant, positive linear correlation between the TEAC, ORAC, PLC-ACW values and content of total phenolic compounds, and also between DPPH and total phenolic acids were found. In the hypocotyl correlations between the DPPH, TEAC, and ORAC and proanthocyanidins content, between TEAC and total phenolic compounds, and between total phenolic acids and PCL-ACW were found

    Critical evaluation of starch-based antibacterial nanocomposites as agricultural mulch films: Study on their interactions with water and light

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    In order to evaluate the potentiality of novel formulations based on starch to be used as agricultural mulch films, native and oxidized corn starch nanocomposites were prepared by extrusion using natural (Bent) and chitosan-modified bentonite (Bent-CS) fillers. The nanocomposite interactions with water were studied by means of moisture content (MC) determination, water solubility (WS), water vapor permeability (WVP), and contact angle (CA). The light transmission spectra were analyzed in order to determine the transparency and radiometric properties of films. Mechanical properties are also included and related with the cryo-fractured surface morphology observed by scanning electron microscopy (SEM). Finally, the antimicrobial action of developed nanocomposites was investigated against the phytopathogen bacterium Pseudomonas syringae pv tomato DC3000 (Psy). Results suggest that starch oxidation leads to a reduction in polarity and transparency. The incorporation of nanoclays improved water resistance but did not produce a significant effect in WVP and mechanical properties, and new strategies are required to improve the nanocomposite performance. However, the incorporation of Bent-CS exerted antibacterial activity on nanocomposites, which is an encouraging result.Fil: Merino, Danila. 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; ArgentinaFil: 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; ArgentinaFil: Mansilla, Andrea Yamila. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Biológicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; ArgentinaFil: Casalongue, Claudia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Biológicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; ArgentinaFil: Alvarez, Vera Alejandra. 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

    Composite foams made from biodegradable polymers for food packaging applications

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    Polymeric foams are cell structures (porous microstructures) that have been frequently made from synthetic polymers for use in the development of food packaging. Due to the problems concerning the environmental impact caused by polymers from the petrochemical industry, the foams have been more recently studied from biodegradable polymers. However, the polymer materials obtained are usually susceptible to moisture, thus conditioning the collapse of the porous structure of the material. As an alternative, the composite foams have been investigated from nanofillers such as clays, cellulose, nanoparticles, among others. This chapter aims to analyze the recent advances in the studies of composite foams.Fil: Araque Moreno, Luis Miguel. Federal University Of Piauí; BrasilFil: Alvarez, Vera Alejandra. 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; ArgentinaFil: 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

    Skin and skeletal system lesions of european pond turtles (Emys orbicularis) from natural habitats

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    Water pollution is known to play an important role in the pathogenesis of plastron, carapace and skin diseases of turtles. In this study, a total of 150 European pond turtles (Emys orbicularis) of different age and both sexes, originating from natural habitats in Serbia, were examined for morphological changes of the skin, plastron, carapace and skeletal system. The turtles were taken out from their natural habitats in Lake Ludas, Lake Palic and Lake Tresetiste. After artificial hibernation, they were subjected to detailed examination, sampled and treated, and finally returned into their natural habitat. Biopsies from the skin and shell were subjected to histopathological examination and microbiological analysis. X-ray scanning was also performed to detect changes in the skeletal system. Macroscopic changes of the skin, most frequently degenerative, inflammatory or neoplastic diseases, were diagnosed in 49.33% of the turtles examined. Dermatitis of different origin and form was the most prominent histopathological finding (28.00%). In the plastron, inflammatory and degenerative processes were frequently found. Osteopathy and mechanical injuries were the dominant findings. Macroscopic changes of the plastron, carapace and skeletal system were diagnosed in 67.33% of the turtles examined. Using X-ray scanning, generalised osteopathy, anomalies and malformations of different aetiology were also diagnosed on the tail and legs. Microbiological examinations showed the presence of a variety of bacterial and fungal agents, either primary pathogens or potential polluters, which invaded the skin and shell, or were present in cloacal swab samples. Bacterial infection was diagnosed in 76.66% of the turtles, first of all in those with skin and shell necrosis. Mycoses were diagnosed in 33.33% of the animals

    Chitosan–Starch–Keratin composites: Improving thermo-mechanical and degradation properties through chemical modification

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    The lysozyme test shows an improved in the degradability rate, the weight loss of the films at 21 days is reduced from 73 % for chitosan-starch matrix up to 16 % for the composites with 5wt% of quill; but all films show a biodegradable character depending on keratin type and chemical modification. The outstanding properties related to the addition of treated keratin materials show that these natural composites are a remarkable alternative to potentiat-ing chitosan–starch films with sustainable featuresChitosan–starch polymers are reinforced with different keratin materials obtained from chicken feather. Keratin materials are treated with sodium hydroxide; the modified surfaces are rougher in comparison with untreated surfaces, observed by Scanning Electron Microscopy. The results obtained by Differential Scanning Calorimetry show an increase in the endothermic peak related to water evaporation of the films from 92 °C (matrix) up to 102–114 °C (reinforced composites). Glass transition temperature increases from 126 °C in the polymer matrix up to 170–200 °C for the composites. Additionally, the storage modulus in the composites is enhanced up to 1614 % for the composites with modified ground quill, 2522 % for composites with modified long fiber and 3206 % for the composites with modified short fiber. The lysozyme test shows an improved in the degradability rate, the weight loss of the films at 21 days is reduced from 73 % for chitosan-starch matrix up to 16 % for the composites with 5wt% of quill; but all films show a biodegradable character depending on keratin type and chemical modification. The outstanding properties related to the addition of treated keratin materials show that these natural composites are a remarkable alternative to potentiat-ing chitosan–starch films with sustainable featuresUniversidad Autónoma del Estado de México Tecnológico Nacional de México, Instituto Tecnológico de Querétaro Universidad Nacional Autónoma de México Tecnológico Nacional de México, Instituto Tecnológico de Celaya Universidad Autónoma de Cd. Juáre
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