Bio-Based Coatings for Food Metal Packaging Inspired in Biopolyester Plant Cutin.

Metals used for food canning such as aluminum (Al), chromium-coated tin-free steel (TFS) and electrochemically tin-plated steel (ETP) were coated with a 2-3-µm-thick layer of polyaleuritate, the polyester resulting from the self-esterification of naturally-occurring 9,10,16-trihydroxyhexadecanoic (aleuritic) acid. The kinetic of the esterification was studied by FTIR spectroscopy; additionally, the catalytic activity of the surface layer of chromium oxide on TFS and, in particular, of tin oxide on ETP, was established. The texture, gloss and wettability of coatings were characterized by AFM, UV-Vis total reflectance and static water contact angle (WCA) measurements. The resistance of the coatings to solvents was also determined and related to the fraction of unreacted polyhydroxyacid. The occurrence of an oxidative diol cleavage reaction upon preparation in air induced a structural modification of the polyaleuritate layer and conferred upon it thermal stability and resistance to solvents. The promoting effect of the tin oxide layer in such an oxidative cleavage process fosters the potential of this methodology for the design of effective long-chain polyhydroxyester coatings on ETP

Polyester films obtained by noncatalyzed melt-condensation polymerization of aleuritic (9,10,16-Trihydroxyhexadecanoic) acid in air

To mimic nontoxic and fully biodegradable biopolymers like the plant cutin, polyester films from a natural occurring fatty polyhydroxyacid like aleuritic (9,10,16-trihydroxyhexadecanoic) acid have been prepared by noncatalyzed melt-polycondensation at moderate temperature (150°C) directly in air. The course of the reaction has been followed by infrared spectroscopy, 13C magic angle spinning nuclear magnetic resonance spectroscopy, differential scanning calorimetry and X-ray diffraction and well differentiated stages are observed. First, a high conversion esterification reaction leads to an amorphous rubbery, infusible, and insoluble material whose structure is made out of ester linkages mostly involving primary hydroxyls and partially branched by minor esterification with secondary ones. Following the esterification stage, the cleavage of vicinal secondary hydroxyls and further oxidation to carboxylic acid is observed at the near surface region of films. New carboxylic groups created also undergo esterification and generate cross-linking points within the polymer structure. Additionally, and despite the harsh preparation conditions used, very little additional side reaction like peroxidation and dehydration are observed. Results demonstrate the feasibility of polyester films fabrication from a reference fatty polyhydroxyacid like aleuritic acid by noncatalyzed melt-polycondensation directly in air. The methodology can potentially be extended to similar natural occurring hydroxyacids to obtain films and coatings to be used, for instance, as nontoxic and biodegradable food packaging materialPeer reviewe

Valorization of Tomato Processing by-Products: Fatty Acid Extraction and Production of Bio-Based Materials

A method consisting of the alkaline hydrolysis of tomato pomace by-products has been optimized to obtain a mixture of unsaturated and polyhydroxylated fatty acids as well as a non-hydrolysable secondary residue. Reaction rates and the activation energy of the hydrolysis were calculated to reduce costs associated with chemicals and energy consumption. Lipid and non-hydrolysable fractions were chemically (infrared (IR) spectroscopy, gas chromatography/mass spectrometry (GC-MS)) and thermally (differential scanning calorimetry (DSC), thermogravimetric analysis (TGA)) characterized. In addition, the fatty acid mixture was used to produce cutin-based polyesters. Freestanding films were prepared by non-catalyzed melt-polycondensation and characterized by Attenuated Total Reflected-Fourier Transform Infrared (ATR-FTIR) spectroscopy, solid-state nuclear magnetic resonance (NMR), DSC, TGA, Water Contact Angles (WCA), and tensile tests. These bio-based polymers were hydrophobic, insoluble, infusible, and thermally stable, their physical properties being tunable by controlling the presence of unsaturated fatty acids and oxygen in the reaction. The participation of an oxidative crosslinking side reaction is proposed to be responsible for such modifications.Andalusian Regional Government P11-TEP-7418Spanish Ministerio de Economía y Competitividad AGL2015-65246-R and AGL2017-83036-RFondo Europeo de Desarrollo Regional (FEDER) AGL2015-65246-R and AGL2017-83036-

Erradicación de Onion Yellow Dwarf Virus (OYDV) en cebolla Shallot (Allium cepa var. Aggregatum), mediante el Cultivo de meristemas, quimioterapia y termoterapia para la producción de bulbos libres de virus

Shallot onions (Allium cepa var. Aggregatum) are highly used and valued in gastronomy, due to its high content of total solids, fatty acids and sugars. It also has potential for medical applications because of its antimicrobial, antithrombotic and anti carcinogenic properties. Obstacles found for the production of Shallot are viral infections like the ones caused by OYDV virus. OYDV is a Potyvirus, which affects the growth and development of this type of onions, reducing its production up to 50%. To solve this issue, OYDV virus should be eliminated with the aim of obtaining free virus bulbs, which can serve as initial material for the next culture cycle. A strategy to accomplish this is meristem culture, or the use of this method with treatments such as thermotherapy and chemotherapy. The objective of the present study was to test the mentioned methodologies, for OYDV virus elimination from Shallot onions of the family A17 from the Experimental Farm of University San Francisco de Quito (USFQ). One hundred bulbs from this family have been used to obtain basal discs in a (MS) medium supplemented with sacarose 30 g.L-1, benomyl 3 g.L-1 , agar 7g.L-1 , NAA 1,1uM + BAP 8,9uM; from these, apical meristems have been isolated. The meristems were cultured in a regeneration medium (MS) supplemented with sacarose 30 g.L-1, benomyl 1.5 g.L-1 , agar 7g.L-1 , NAA 1,1uM + BAP 8,9uM. Following then, by a rooting-stage in a (MS) medium, supplemented with sacarose 30 g.L-1 and agar 7g.L-1; followed by a bulb-stage formation in a (MS) medium, supplemented with sacarose 30g.L-1, 150mg L-1 of NaH2PO4, agar 7g.L-1 and 10uM of Ancymidol. Finally, the plants passed through a process of acclimatization. The treatment of thermotherapy consisted on culturing the meristems at 38º C for 4 days and chemotherapy in culturing the meristems in the regeneration culture with 50 mg/L of Ribavirin. In addition, a treatment of combined therapies was applied to the meristems at 38º C for 4 days and 25 mg/L Ribavirin in the regeneration medium. Before and after the therapies, the OYDV virus presence was verified through RT-PCR. The most efficient treatments for OYDV virus elimination were chemotherapy and combined therapies with both 100% of OYDV virus elimination, followed by thermotherapy (60%) and control (53%). According to the obtained results, it can be said that the treatments of chemotherapy and combined therapies are advisable to obtain free Shallot onions of OYVD virus. It is also recommended to optimize the protocol of in vitro regeneration of meristems, to get a larger number of Shallot bulbs. These can be used to improve the production of this type of onion with interesting uses in the gastronomic industry.La cebolla Shallot (Allium cepa var. Aggregatum) es apetecida en la industria gastronómica por su alto contenido de sólidos totales, ácidos grasos y azúcares. También tiene potenciales aplicaciones medicinales por sus propiedades antimicrobianas, antitrombóticas, y anticancerígenas. Un limitante para la producción de Shallot son las infecciones virales, como las causadas por el virus OYDV, un Potyvirus que afecta el crecimiento y desarrollo de este tipo de cebollas, reduciendo la producción de esta variedad hasta en un 50%. Para resolver este problema, se debe erradicar el virus OYDV de las plantas infectadas a fin de obtener bulbos libres de virus que sirvan como material inicial para los siguientes ciclos de cultivo. Una estrategia para conseguir esto es el cultivo de meristemas, o el uso de este método de cultivo junto con tratamientos de termoterapia y quimioterapia. El objetivo del presente estudio fue probar las metodologías mencionadas, para la erradicación del virus OYDV en cebolla Shallot de la familia A17 de la Granja Experimental de la Universidad San Francisco de Quito (USFQ). Se utilizaron 100 bulbos de esta familia, a partir de los cuales se obtuvieron discos basales en medio (MS) suplementado con, sacarosa 30 g.L-1, benomyl 3 g.L-1 , agar 7g.L-1 , NAA 1,1uM + BAP 8,9uM. y de éstos, se aislaron meristemas apicales. Los meristemas fueron cultivados en un medio de regeneración (MS) suplementado con, sacarosa 30 g.L-1, benomyl 1.5 g.L-1 , agar 7g.L-1 , NAA 1,1uM + BAP 8,9uM. Siguiendo luego una fase de enraizamiento en medio (MS) ) suplementado con, sacarosa 30 g.L-1, y agar 7g.L-1, seguidos por embulbamiento en un medio (MS) adicionado sacarosa 30g.L-1, 150mg L-1 de NaH2PO4, agar 7g.L-1. y 10uM de Ancymidol. Finalmente las plantas pasaron por un proceso de aclimatación. El tratamiento de termoterapia consistió en cultivar los meristemas a 38º C por 4 días y el de ,quimioterapia en cultivar los meristemas en el medio de regeneración más 50 mg/L Ribavirina. Además se realizó un tratamiento de terapias combinadas 38º C por 4 días y 25 mg/L Ribavirina en el medio de regeneración. Antes y después de los tratamientos se verificó la presencia de virus OYDV mediante RT-PCR. Los tratamientos más eficientes para la erradicación de virus OYDV, fueron la quimioterapia y terapias combinadas con 100% de erradicación, seguidas por termoterapia (60%) y control (53%). De acuerdo a los resultados obtenidos se puede decir que los tratamientos de quimioterapia y de terapias combinadas son aconsejables para obtener plantas de cebolla Shallot libres del virus OYDV. Es aconsejable optimizar el protocolo de regeneración in vitro de meristemas para obtener un número mayor de bulbos de Shallot que puedan ser utilizadas para mejorar la producción de este tipo de cebolla con interesantes usos en la industria culinaria

Chemical-physical characterization of isolated plant cuticles subjected to low-dose γ-irradiation

Isolated tomato fruit cuticles were subjected to low dose (80 Gy) γ-irradiation, as a potential methodology to prevent harvested fruit and vegetables spoilage. Both irradiated and non-irradiated samples have been morphologically and chemically characterized by scanning electron (SEM), atomic force (AFM), attenuated total reflectance Fourier transform infrared (ATR-FTIR) and X-ray photoelectron (XPS) spectroscopies. Additionally, electrochemical measurements comprising membrane potential and diffusive permeability were carried out to detect modifications in transport properties of the cuticle as the fruit primary protective membrane. It has been found that low dose γ-irradiation causes some textural changes on the surface but no significant chemical modification. Texture modification is found to be due to a partial removal of outermost (epicuticular) waxes which is accompanied by mild changes of electrochemical parameters such as the membrane fixed charge, cation transport number and salt permeability. The modification of such parameters indicates a slight reduction of the barrier properties of the cuticle upon low dose γ-irradiation.

ED010. Distribución actualizada de Pellaea stictica Dallas, 1851 (Hemiptera: Pentatomidae) en los andes tropicales

Pellaea stictica Dallas, is a stinkbug of the Pentatomidae from the American continent. Recent reports from different countries reveal that its distribution throughout the tropical Andes is broader than previously reported. In this study we carry out a bibliographic review of the data published on P. stictica in Latin America, we compile information obtained from citizen science platforms and we collect field data for the identification of samples collected in museums. Through this process, the presence of the insect in different locations in Ecuador was corroborated and information on the plants it consumes was expanded. From these data, a possible dispersion by host plants that share their historical distribution in the tropical Andes is proposed. It is recommended to carry out more studies on the distribution and ecology of the species and to promote data curation in citizen science platforms.Pellaea stictica Dallas, 1851 es una chinche de la familia Pentatomidae del continente americano. Reportes recientes provenientes de diferentes países revelan que su distribución a lo largo de los Andes tropicales es más amplia de lo que se ha datado anteriormente. En este estudio, realizamos una revisión bibliográfica de los datos publicados sobre P. stictica en Latinoamérica, compilamos información obtenida en plataformas de ciencia ciudadana y colectamos datos de campo para la identificación de muestras colectadas en museos. Mediante este proceso, se corroboró la presencia del insecto en diferentes localidades del Ecuador y se expandió información acerca de las plantas que consume. A partir de estos datos, se plantea una posible dispersión por plantas hospedadoras que comparten su distribución histórica en los Andes tropicales. Se recomienda realizar más estudios sobre la distribución y ecología de la especie y que se promueva la curación de datos en plataformas de ciencia ciudadana

Editorial: Non-polysaccharide Plant Polymeric Materials

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Alginate nanofibers with tunable biodegradability for regenerative medicine [Abstract]

Alginate nanofibers with tunable biodegradability for regenerative medicine [Abstract

Collaborative Learning Based on Harry Potter for Learning Geometric Figures in the Subject of Mathematics

Nowadays, education requires changes in the teaching and learning processes, through the implementation of innovative and motivating pedagogical actions, owing to the existing needs in society. Education, owing to the current needs of society, requires changes in the teaching and learning processes through the implementation of innovative and motivating pedagogical actions. The main objective of this study is to evaluate the effectiveness of the collaborative method, based on the Harry Potter theme, with respect to the traditional method in the first year of Obligatory Secondary Education for the learning of geometric figures in the subject of mathematics. For this purpose, a quasi-experimental, quantitative, descriptive, and correlational study has been designed, using a standardized questionnaire as a technique to collect information. The sample is composed of 236 students from the first year of Obligatory Secondary Education distributed in eight groups (four control and four experimental) from a public high school in the city of Cádiz (Spain). The tests carried out show that collaborative learning generates improvements in the attitudes and mathematical dimensions. Therefore, the collaborative method, developed by means of the Harry Potter theme for students in the first year of Compulsory Secondary Education in the subject of mathematics, causes a better attitude of the student towards the teaching and learning process. Furthermore, it facilitates the acquisition of mathematical contents related to geometry, which does not directly affect the students’ grades because, although those of the experimental group are better than those obtained by the control group, the differences between the two are minimal