Resumen El uso de películas comestibles es una tecnología para alargar la vida útil de los alimentos. La adición de nanopartículas de plata (AgNPs) podría mejorar el desempeño de películas comestibles y evitar el crecimiento de microorganismos que podrían afectar a los alimentos. El objetivo fue elaborar y caracterizar AgNPs mediante síntesis verde y evaluar el efecto de su adición sobre las propiedades mecánicas y de barrera de películas formadas a partir de proteína de Cajanus cajan y goma de la semilla de Tamarindus indica. Para la síntesis de AgNPs se utilizó extracto acuoso de Annona muricata. Tres diferentes formulaciones de películas se elaboraron las cuales contenían AgNPs, extracto acuoso de guanábana y agua (control). Las películas fueron evaluadas en términos de su permeabilidad al vapor de agua (WVP), color, opacidad y propiedades mecánicas. Las AgNPs incrementaron el doble el módulo de Young de las películas (0.0675 MPa) y la fuerza de tensión (2.84 MPa) con respecto al control. Además, las AgNPs influyeron estadísticamente en el color y opacidad de la película. Sin embargo, no se observaron diferencias en la PVA. La adición de AgNPs a recubrimientos podría ser una opción para incrementar la vida útil de alimentos.

Abstract The use of edible films is a technology to extend the shelf life of food. The addition of silver nanoparticles (AgNPs) could improve the performance of edible films and avoid the growth of microorganisms that could affect food. The objective was to elaborate and characterize AgNPs by green synthesis and to evaluate the effect of their addition on the mechanical and barrier properties of films formed from Cajanus cajan protein and Tamarindus indica seed gum. An aqueous extract of Annona muricata leaves was used for green synthesis. Three films were developed containing AgNPs, aqueous extract of Annona muricata leaves and water (control). Films were evaluated by their water vapour permeability (WVP), color, opacity and mechanical properties. The AgNPs increased two-fold the Young’s module (0.0675 MPa) and the tensile strength (2.84 MPa) in relation to control film. Moreover, the AgNPs influenced also the color and opacity of the films. However, no differences were observed in the WVP. The addition of AgNPs to films, could be an option to increase the shelf life of foods.

SUMMARY: This work was conducted with the objective to evaluate the effect of vermicompost application on chemical characteristics, energetic parameters and amino acids profile of hybrid race corn grain cultivated under open-field and rained conditions. The experiment was accomplished under a randomized complete design with three repetitions. Three treatments were evaluated: 1) Maize after inoculation with a commercial mycorrhizal arbuscular fungi mixture (Tec Myc 60®) plus vermicompost (V+M); vermicompost (V) and chemical fertilization (CF). Starch content in grain was 1.9% higher in V+M treatment in comparison with chemical, whereas crude protein, ether extract, crude fiber, acid detergent fiber, neutral detergent fiber, total phosphorous and phytic phosphorous were not different between treatments. Energetic parameters were not different between three treatments. 17 amino acids were evaluated of wich only tryptophan, leucine, valine, histidine and aspartic acid were higher in CF and V treatments in comparison with V+M treatment. In conclusion, it is possible to cultivate maize using vermicompost as fertilizer because chemical characteristics, energetic parameters and amino acids profile in maize grain were not affected compared with the maize cultivated with vermicompost added with biofertilizers (V+M) or with corn cultivated with chemical fertilizers (CF).

RESUMEN: Este trabajo tuvo como objetivo evaluar el efecto de la aplicación de vermicomposta sobre las características químicas, parámetros energéticos y perfil de aminoácidos de híbridos de maíz bajo condiciones de campo y con lluvia de temporal. El diseño experimental fue completamente al azar con tres repeticiones. Se evaluaron tres tratamientos: 1) maíz después de inoculación con una mezcla de hongos micorrízicos arbusculares (Tec Myc 60®) más vermicomposta (V + M); vermicomposta (V) y fertilización química (CF). El contenido de almidón en los granos fue 1.9% más elevado en el tratamiento V+M en comparación con el tratamiento con fertilización química, mientras que la proteína cruda, extracto etéreo, fibra cruda, fibra detergente ácida, fibra detergente neutra, fósforo total y fósforo fítico no fueron diferentes entre los tratamientos. Los parámetros energéticos no fueron diferentes entre los tres tratamientos. De los 17 aminoácidos, solo triptófano, leucina, valina, histidina y ácido aspártico fueron más elevados en los tratamientos CF y V en comparación con V+M. En conclusión, es posible cultivar maíz usando vermicomposta como fertilizante porque las características químicas, parámetros energéticos y perfil de aminoácidos en los granos de maíz no son diferentes a los obtenidos en maíz cultivado con vermicomposta y biofertilizantes (V+M) o con maíz cultivado con fertilización química (CF).

Abstract Yam bean (Pachyrhizus erosus (L.) Urb.) tuber has a low carbohydrate content and contains several aminoacids, but contains few active compounds, such as vitamins and antioxidants. Anthocyanins are antioxidants found in Rubus fructicosus L. The osmotic drying is a technique that can be used to impregnate antioxidants in a matrix, so the objective of this study was to impregnate yam bean tuber slices with anthocyanin. The effect of temperature (40, 50 and 60oC), sucrose content (40, 50 and 60oBrix) and vacuum pulse (0, 300 and 600 mbar) on water loss (WL), solid gain (SG), color changes (ΔΕ) and anthocyanin concentration (ΔA) during osmotic drying of yam bean slices was determined. Polynomial equations were used to determine changes in WL, SG, ΔΕ and ΔA of yam bean slices after 6 h of osmotic drying. An osmotic solution at 60oC with a SC of 40oBrix, applying a vacuum pulse of 12 mbar maximized anthocyanin impregnation (6.67 mg anthocyanin per g initial dry matter) in tuber slices. The Page equation predicted optimum WL, SG and ΔA of yam bean tuber slices during osmotic drying. No relation was found between temperature, sucrose content and vacuum pulse with K and n parameters in the Page equation.

Current protocols for Agave americana L. micropropagation have limited commercial application due to the low number of plants produced by explant. Indirect organogenesis could be an alternative, however is necessary to optimize plant growth regulators for plantlet number maximization. The objective of this work was to optimize 2,4-dicholorophenoxyacetic acid (2,4-D) and 6-benzyl adenine (BA) concentrations on the induction of A. americana embryogenic callus from apical meristem as explant for maximized the number of shoots per callus using a response surface experimental design. MS medium containing 30 g l-1 sucrose amended with 0.11,0.18, 0.45 or 2.26 μM 2,4-D, and 11.0, 22.0, 38.2 or 44.0 μM BA was used. Nine treatments with three repetitions was applied and number of shoots per callus were monitored after 4, 16, 20 and 36 weeks. In vitro rooting of shoot was done in MS medium added with indole butyric acid (IBA). A maximum number of plantlets per explant (74) was obtained with 2.26 μM of 2,4-D and 38.2 μM BA. In conclusion, the indirect organogenesis of A. americana L. could be an alternative for obtain plantlets for propagation commercial purposes.

Los protocolos actuales para la micropropagación de Agave americana L. tienen limitaciones para su aplicación comercial debido al bajo número de plantas producidas por cada explante. La organogénesis indirecta podría ser una alternativa, sin embargo, es necesario optimizar los reguladores de crecimiento vegetal para maximizar el número de plantas. El objetivo del trabajo fue optimizar la concentración de ácido 2,4-diclorofenoxiacetico (2,4-D) y de 6-bencil adenina (BA) sobre la inducción de callos embriogénicos en A. americana usando meristemos apicales como explante para maximizar el número de brotes por callo, utilizando un diseño experimental de superficie de respuesta. Se utilizó el medio Murashige Skoog (MS) adicionado con 30 g l-1 de sacarosa, y con 0,11;0,18; 0,45 o 2,26 μM de 2,4-D, y 11,0; 22,0; 38,2 o 44,0 μM de BA. Se implementaron 9 tratamientos con 3 repeticiones y el número de brotes por callo fue evaluado después de 4, 16, 20 y 36 semanas. Se indujo el enraizamiento in vitro usando medio MS adicionado con ácido indolbutírico (AIB). Se obtuvo un máximo de 74 plántulas por callo, usando 2,26 μM de 2,4-D y 38,2 μM de BA. En conclusión, la organogénesis indirecta podría ser una alternativa para la micropropagación de A. americana L con fines comerciales.

The objective of this study was to investigate the effect of vermicompost, worm-bed leachate (WBL) and Glomus mosseae, an arbuscular mycorrhizal fungi (AMF), on growth of lemongrass (Cymbopogon citratus (DC.) Stapf). A response surface methodology, i.e. a three-level Box Benhen design with three repetitions and three blocks, was applied to optimize biomass production, essential oil yield and its composition. Application rates of Glomus mosseae were 0, 1 or 2 g plant-1, vermicompost 0, 5 or 10 g plant-1 and WBL 0, 10 and 20%. The AMF had no significant effect on the variables tested, but vermicompost had a significant effect on essential oil yield and WBL on essential oil yield, myercene concentration and shoot dry weigh (p < 0.05). It was found that lemongrass fertilized with 2.0 g G. mosseae, 5.0 g vermicompost and 20% worm-bed leachate would yield 0.797% essential oil of which 62.6% was citral.

O objectivo deste estudo foi a avaliação da efectividade das misturas en diferentes níveis de lactose-maltodextrina (8:5, 10:5, 12:5 % w/v) durante a pulverização do sumo de maracujá. A secagem foi feita em um atomizador de laboratório de pulverização (modelo Pulvis GB 22) com 2 entradas de temperatura de ar (180 e 190 ºC), e 2 compressores de pressão de ar (0.10 e 0.20 MPa). O índice da mistura, higroscopicidade e retenção de vitamina C foram avaliados no pó obtido. As curvas de superfície de resposta (p<0.05) mostram que os valores mais baixos do índice da mistura e higroscopicidade foram alcançados no intervalo de temperatura de 188-190 ºC e com uma concentração de 12:5 % w/v de lactosemaltodextrina; o melhor nível de retenção de vitamina C ocorreu a 180 ºC e 0.2 MPa.

The objective of this study was to assess the effectiveness of the blends with different levels of lactose-maltodextrin (8:5, 10:5, and 12:5 % w/v) during the spray-drying of the passion fruit juice. The drying was carried out in a laboratory spray dryer (Pulvis GB 22 model) at two inlet air temperatures (180 and 190 ºC), and two air pressures (0.10 and 0.20 MPa). The moisture content, hygroscopicity and vitamin C retention were evaluated in the powder obtained. Response surface plots (p<0.05) showed that the lowest values of the moisture content and hygroscopicity were reached in the temperature range of 188-190 ºC and at 12:5 % (w/v) concentration of lactose-maltodextrin; the best vitamin C retention level occurred at 180 ºC and 0.2 MPa.

The objective of this work was to assess the effect of two arbuscular mycorrhizal fungi (AMF) at different phosphorus concentrations on survival and growth of pineapple {Ananas comosus (L.) Merr.) plantlets obtained for micropropagation. Plantlets were multiplied for in vitro cultures and were acclimatized under three sequential steps. The effects of AMF and phosphorus were not significant on plantlet survival and plantlet height, however Glomus claroideum stimulated that the plantlets were with higher leaves number and dry weight. The results demonstrated that plantlet growth was maximized with G claroideum and phosphorus 0.9 mM.

El objetivo del trabajo fue evaluar el efecto de dos hongos micorrízicos arbusculares (HMA) a diferentes concentraciones de fósforo sobre la sobrevivencia y el crecimiento de plántulas de pina {Ananas comosus (L.) Merr.) obtenidas por micropropagación. Las plántulas se multiplicaron masivamente en cultivos in vitro y se aclimataron gradualmente bajo un esquema de estrés por temperatura en tres etapas secuenciales. Los efectos de los HMA y el fósforo no fueron significativos sobre la sobrevivencia y la altura de las plántulas, sin embargo, Glomus claroideum estimuló que las plántulas tuvieran mayor número de hojas y peso seco. Los resultados sugieren que la altura de las plántulas fue mayor cuando fueron cultivadas con G. claroideum y 0,9 mM de fósforo.