69 research outputs found

    Microwave-assisted extraction of Ulva spp. including a stage of selective coagulation of ulvan stimulated by a bio-ionic liquid

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    Microwave-assisted hydrothermal processing was proposed to recover high valuable compounds with antioxidant and gelling features from Ulva spp. green seaweed. The influence of the extraction conditions on the solubles, ulvan fraction and residual solid phase was studied to achieve a global valorization of the seaweed. A particular emphasis was placed on the selective coagulation of ulvan stimulated by a bio-ionic liquid during the extraction process. The achieved outcomes indicated that the selected microwave treatment exhibited a notable impact on the phytochemical properties of the soluble extracts, with the highest values of sulfate and protein content at 160 °C, and the highest antioxidant features at 200 °C. The most prominent molecular weight distributions were also identified for systems hydrothermal treated at 160 °C. The ulvan analyses showed that those extracted after microwave treatment at 160 °C showed the highest yields, molecular weight and the strongest gel features from the rheological point of view. The presence of the chloride chlorine during the extraction process favored the ulvan performance and the enhancement of the corresponding viscoelastic properties.Agencia Estatal de Investigación | Ref. RYC2018-024454-IXunta de Galicia | Ref. ED431F 2020/01ED481D-2022/018Financiado para publicación en acceso aberto: Universidade de Vigo/CISU

    Extraction of ferulic acid from agro-industrial wastes and evaluation of bioconversion of ferulic acid to vanillin by Streptomyces setonii

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    Several agro-industrial wastes (as chestnut and pistachio shells, grass, leaf fruit, vine leaf,and, red and white grape stems) were evaluated to ferulic acid extraction. The chemical analysis of these raw materials shows a high content of xylan in pistachio shells (33%), following the biorefinery concept, this fraction can be used in xylitol manufacture. The lignocellulosic materials were submitted to an alkaline extraction to obtain phenolic compounds, reaching a concentration of 312 mg ferulic acid/L in grass wastes. Other phenolic compounds were also extracted (gallic acid, p-coumaric acid, syringic acid etc.) depending of used raw material. Besides, the ferulic fermentation into vanillin was assayed. The higher concentration of vainillin (2692 mg/L) was achieved at 27 h (QP = 99.704 mg/L·h and YP/S = 0.50 mg/mg) using Streptomyces setonii

    Spray-drying microencapsulation of tea extracts using green starch, alginate or carrageenan as carrier materials

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    Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGTea industry generates many by-products which could be used to produce and incorporate bioactive tea extracts (TE) into nutraceuticals, cosmetics and/or clinical applications. However, sensibility to external factors is a major disadvantage hindering its utilization. This study deals with the implementation and characterization of suitable biopolymer delivery systems based on starch, carrageenan or alginate, as microencapsulation, to stabilize and protect TE through innovative thin-carbohydrate-coated formulations. TE were spray-dried and microencapsulated in recycled carrier materials (alginate, carrageenan or starch). Product yields varied from 55 to 58%. High microencapsulation and loading efficiencies were achieved (60–93% and 65–84%, respectively). Antioxidant capacity varied from 32 to 46 g Trolox/100 g extract, within different carrier-systems; which also showed promising rheological and UV-protective properties when transformed into gels. Total phenolic content, particle-size distribution, HPSEC-analysis, SEM-analysis and FTIR-analysis were also performed. In sum, this paper characterizes and discusses the high potential of these recycled carbohydrate-coated microparticles for future applicationsMinisterio de Ciencia, Innovación y Universidades | Ref. RYC2018-024454-IXunta de Galicia | Ref. ED431F 2020/01Xunta de Galicia | Ref. ED481B 2018/07

    Valorisation of Camellia sinensis branches as a raw product with green technology extraction methods

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    This work deals with the study of tea stalks from pruning debris using environmental friendly extraction technology to offer new healthy properties. In the manufacturing tea industry, tea trees require to be pruned every year and most of their remains are discarded as a waste with no economic value. Microwave aqueous extraction and pressurized hot water extraction process (autohydrolysis) were used to recover bioactive compounds from the tea branches. Operating at a fixed solid: liquid ratio (1:15), the effect of the maximum heating temperatures from 140 to 220 °C was studied. Liquid extracts were analysed for total phenolic, oligosaccharides, protein, mineral and heavy metals content, as well as for antioxidant capacity. The antitumoral possibilities were also determined for selected samples. The obtained results indicated that both processes could be used as an alternative to recover bioactive compounds from tea wastes, although microwave-assisted extraction allowed saving time when compared with autohydrolysis processing. The temperature exhibited a relevant effect on the total phenolic content and antioxidant capacity, decreasing with the microwave treatment and increasing with the autohydrolysis temperature. The obtained extracts could be adequate for incorporation in food and non-food fields.Ministerio de Economía y Competitividad | Ref. IJCI-2016-27535Ministerio de Ciencia, Innovación y Universidades | Ref. RYC2018- 024454-

    Green extraction of antioxidant fractions from Humulus lupulus varieties and microparticle production via spray-drying

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    The formulation of polymeric microparticles to encapsulate bioactive compounds from two hop varieties (Nugget and Perle) using sequential green extraction processes was performed. The technologies used were ultrasound-assisted extraction (UAE) and pressurized hot water (PHW) extraction. Liquid phases were analyzed for total phenolic content (~2%), antioxidant activity (IC50, DPPH: 3.68 (Nugget); 4.46 (Perle) g/L, TEAC (~4–5%), FRAP (~2–3%), and reducing power (~4%)), protein content (~1%), oligosaccharide content (~45%), and for structural features. The fractions obtained from UAE were selected to continue with the drying process, achieving the maximum yield at 120 °C (Perle) and 130 °C (Nugget) (~77%). Based on these results, the formulation of polymeric microparticles using mannitol as the carrier was performed with these fractions. The production yield (~65%), particle size distribution (Perle: 250–750 µm and Nugget: ~100 µm), and rheological features (30–70 mPa s at 0.1 s−1) were the parameters evaluated. The UAE extracts from hop samples processed using a sustainable aqueous treatment allowed the formulation of microparticles with a suitable yield, and morphological and viscosity properties adequate for potential food and non-food applications.Agencia Estatal de Investigación | Ref. RYC2018‐024454‐IXunta de Galicia | Ref. ED431F 2020/01Xunta de Galicia | Ref. ED481D‐2022‐01

    Determinación del grado de acidez de vinagres comerciales de distinta materia prima

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    El objetivo principal de esta investigación es la determinación de la cantidad de ácido acético en diferentes vinagres comerciales mediante una valoración ácido-base para determinar el grado de acidez de los mismos, relacionarlos con las diferentes denominaciones de origen y los distintos tipos de envejecimiento. Así mismo se comprobará que cumplen los límites legales establecidos en relación a acidez y residuo sec

    Potential use of Sargassum muticum as source of plant biostimulants after three different drying methods

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    Seaweed derived biostimulants are gaining attention as an important tool in sustainable agriculture. This offers a unique opportunity to alleviate the environmental impact of Sargassum muticum (Ochrophyta, Phaeophyceae) as an invasive species by finding new applications for its biomass. In this sense, incorporating green extraction technologies is fundamental to ensure environmental-friendly goals. This research was initiated in an attempt to contribute to an integral valorization system of S. muticum biomass, exploring the biostimulant potential of the solubles obtained from pressed solids, through an autohydrolysis treatment. In addition, we compared the effect of three different liquid phase drying techniques (spray-drying, freeze-drying and convective air-drying). Low stress drying techniques as spray-drying showed better conservation of bioactive compounds and biostimulant potential. A bioassay with Nastrium officinale showed no phytotoxic effects despite high electric conductivity in most of the extracts and concentrations. Dried extracts showed mainly an amorphous structure but occasional crystal formation when spray-dried at low temperatures (T out  = 50 ºC) and after convective air drying (T = 40 ºC). Significant increases in root development were achieved at a concentration of 5 mg L −1 of spray-dried extracts and 50 mg L −1 in case of freeze-dried extracts. Munoo-Liisa vitality index showed best results with 50 mg L −1 of freeze-dried extracts. This study provides important information about the influence of different drying techniques on the physicochemical properties and biostimulant potential of S. muticum aqueous extracts and contributes to the integral valorization of its biomass.Agencia Estatal de Investigación | Ref. RYC2018-024454-IXunta de Galicia | Ref. ED431F 2020/01Xunta de Galicia | Ref. ED481D-2022/018Universidade de Vigo/CISU

    Reflexiones en torno a la enseñanza de la técnica : Observación

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    El presente escrito es el resultado de una serie de reuniones en donde hubo intercambio de opiniones de un grupo de personas, nos permitimos de entrada, mencionar las características y condiciones de este grupo de personas; somos docentes de la Universidad Veracruzana, en México pero tenemos la oportunidad de ejercer la docencia en diferentes facultades de la Universidad Veracruzana, así tenemos que nos encontramos adscritos a la Facultad de Pedagogía, Trabajo Social y Contaduría, respectivamente pero que convergemos en una agrupación denominada Cuerpo Académico (CA), cuyo nombre es “Políticas Públicas y Familias”.Facultad de Humanidades y Ciencias de la Educació

    Atención residencial a personas con demencia. Intervención desde el Trabajo Social

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    Se pretende identificar la forma de intervenir en la atención a personas que sufren demencias desde la disciplina del Trabajo Social, enmarcado en el ámbito de un Servicio Social Especializado, en un centro de atención residencial y dentro de un método de trabajo interdisciplinar. Al mismo tiempo se ha reflexionado, desde la práctica, sobre la importancia del rol del (de la) trabajador(a) social en la atención de las personas que sufren demencias y sus familias

    Study of Fucoidans as Natural Biomolecules for Therapeutical Applications in Osteoarthritis

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    [Abstract] Osteoarthritis (OA) is the most prevalent articular chronic disease. Although, to date there is no cure for OA. Fucoidans, one of the main therapeutic components of brown algae, have emerged as promising molecules in OA treatment. However, the variability between fucoidans makes difficult the pursuit of the most suitable candidate to target specific pathological processes. By an in vitro experimental approach in chondrocytes and fibroblast-like synoviocytes, we observed that chemical composition of fucoidan, and specifically the phlorotannin content and the ratio sulfate:fucose, seems critically relevant for its biological activity. Nonetheless, other factors like concentration and molecular weight of the fucoidan may influence on its beneficial effects. Additionally, a cell-type dependent response was also detected. Thus, our results shed light on the potential use of fucoidans as natural molecules in the treatment of key pathological processes in the joint that favor the development of rheumatic disorders as OA.Xunta de Galicia; ED431G2019/0
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