Acid sulphate soils (ASS) are characterized to be dynamic systems with a continuous chemical degradation processes due to current severe acidification. One of their limitations is related to the inhibition of the absorption of exchangeable bases, generated mainly by excess aluminum rates, which affect their productivity 20and limit the availability of nutrients to plants.This study evaluated the effect of some techniques used in soil remediation on exchangeable bases of ASS, at greenhouse conditions, in order to identify methodologies for the management of these soils in Paipa (Boyacá). An experimental design with 6 treatments and 5 replications was performed, where the incorporation of efficient microorganisms, sugarcane bagasse, green manure and dolomite lime was evaluated as well as the seeding of forage Brassica rapa L.; in which the exchangeable bases were measured before and after planting Brassica oleracea var. Botrytis as indicator crop. For data analysis, was performed ANOVA and was applied Tukey comparison of means with a reliability of 95%. The results indicated that the seeding of B. rapa as forage and incorporating of the same as green manure, with the complementary use of dolomite lime, generated a greater increase in Ca (18.21 cmolc•kg-1 & 16.61 cmolc•kg-1) and Mg (6 cmolc•kg-1 & 5.15 cmolc•kg-1). In terms of K, the highest value was obtained with the addition of green manure (1.31 cmolc•kg-1) respect to the methodologies evaluated.

Excessive rain, a deficient drainage system, and compacted soils are the principal causes of waterlogging, which can generate a reduction in vegetative growth, changes in plant metabolism, low absorption of water and nutrients, low production, and the death of some organs or complete plants. The damage from waterlogging is major with extended stress and in less tolerant plants. Plants are more tolerant with defensive modifications such as alternate routes of respiration, increased production of antioxidants and ethylene, epinasty induction and the closing of stomata, and the formation of new structures such as aerenchyma, hypertrophied lenticels, and adventitious roots. Fruit trees suffer from lack of oxygen due to flooding. However, the lack of oxygen can lead to death of plants; well executed measures can be very useful to attenuate the negative effects of stress.

The use of antimicrobial agents in artificial diets for the mass rearing of insects is commonly employed to prevent the proliferation of environmental microorganisms, preventing contamination of food and space of the rear insects. Therefore, the aim of this research was to evaluate the effect of formaldehyde and nipagine antimicrobials on the Cenibroca artificial diet for coffee berry borer breeding. Through this experiment, using the Cenibroca diet, the largest number of coffee borer biological states per cm3 of diet was achieved, however the highest percentage of contamination by the fungi Aspergillus sp. and Penicillum sp. was obtained. When 2.65 mL of formaldehyde per liter of Cenibroca were added, the least diet contamination (3.3 %) was achieved. This addition did not affect the production of biological states of the coffee borer, in comparison with the rest of diets used, in which other antimicrobial agents were used. Based on these results, it is possible to use the Cenibroca diet in coffee berry borer breeding for the mass production of its parasitoids.

Polycyclic Aromatic Hydrocarbons (PAHs) are important compounds in determining atmospheric pollution produced by combustion from mobile sources, industrial pollution and oil industry. PAHs are considered priority pollutants by the US Environmental Protection Agency US (USEPA), due to its carcinogenic and mutagenic properties. PAHs in food, represent a potential risk to consumers, are easily associated with the particulate matter and finally settle into the sediment and water. In aquatic ecosystems PAHs join the biota of the environment and the fish are excellent biomarkers of his presence. Mutiscua region is influenced by atmospheric pollution from mobile to petrol and diesel driven on a nearby national road to the municipality. The growing interest today in research in the field of organic compounds such as Priority Pollutants (PP), is due to the identification of adverse effects of these pollutants on health and ecosystems. This research is an assessment of the presence of PP in muscle and skin of rainbow trout. The determination of PAHs (PP) was performed by gas chromatography using FID (FlameIonization Detector). It was possible to identify the presence of a mixture of Benzofluorantenos considered as possible carcinogenic to humans, and trace level the possible presence of Benzo(a) pyrene, also classified as a carcinogen.

The present study aimed to evaluate the effect of moisture level on the physiological behavior of different forage grasses. The experiment was conducted in screenhouse at the Center for Research Turipaná of Corpoica, (Cereté, Córdoba). Was used a design randomized complete block with 14 genotypes, and three (3) replications. Three moisture regimes were used in the manner of locations within the same screenhouse. Among the variables studied were: net photosynthesis, transpiration, stomatal conductance, leaf water potential, leaf dry mass, leaf area, among others. Only the variables leaf area and leaf water potential showed significant interactions between genotype and environment of moisture, while the other variables, were most affected by the main factors(p<0.05). Genotypes Bisset, Strikcland and Colosuana had an interaction for leaf area, showing the highest value at high and medium moisture. At low humidity, the 14 forage grasses had more negative leaf water potential. Low level moisture had the lowest values of stomatal conductance and transpiration and lower dry matter accumulation in all organs, mainly the leaves. BR02/1752 had the highest dry matter accumulation in leaves (32.67 gplant-1) followed by CIAT16051 (27.78 gplant-1). It is concluded that the physiological behavior of pastures is determined by genetic characteristics and moisture regime, not by their interaction.> <0.05). Genotypes Bisset, Strikcland and Colosuana had an interaction for leaf area, showing the highest value at high and medium moisture. At low humidity, the 14 forage grasses had more negative leaf water potential. Low level moisture had the lowest values of stomatal conductance and transpiration and lower dry matter accumulation in all organs, mainly the leaves. BR02/1752 had the highest dry matter accumulation in leaves (32.67 gplant-1) followed by CIAT16051 (27.78 gplant-1). It is concluded that the physiological behavior of pastures is determined by genetic characteristics and moisture regime, not by their interaction.

The Tree tomato (Cyphomandra betacea S.) is a fruit of mass consumption in Colombia, due to their special organoleptic and nutritional characteristics. Tree tomato fruits were evaluated for fifteen days during post- harvest stage to establish the evolution of antioxidant activity and concentration of phenolics compounds. The antioxidant capacity was analyzed by the ABTS method. It was found for the sixth day postharvest an average maximum value equivalent to 9.8 µmol of Trolox equivalents per gram of fresh fruit. Total phenols were determined by Folin Ciocalteu method, finding the highest concentration of phenolic compounds for the eighth day post-harvest, with 1.23 milligrams of gallic acid per gram of fresh fruit. The concentration of phenolic compounds was growing from day one of postharvest, then remained constant until day 11, showing a decrease to days 12 to 14 on ripening stage. In conclusion, it was established that the antioxidant activity in post harvest stage of tree tomato didn't present significant differences with a confidence level of 95%. The results obtained presented no positive correlation between antioxidant capacity and total phenolic concentration, however it was possible to conclude that tree tomato fruit is classified as a high antioxidant activity and good concentration of phenolic compounds compared to other fruits reported in various researches, aspects that power consumption of this species as a nutraceutical food.

Un grupo creciente de evidencias sugiere que el consumo regular de los productos del cacao o el uso de sus principios activos como agentes terapéuticos podrían influir favorablemente en la lucha contra las enfermedades como aterosclerosis, procesos carcinogénicos, colesterol entre otras. Lo anterior es debido a los componentes nutricionales propios del chocolate, los cuales ejercen efectos positivos en el cuerpo humano. Por lo anterior es importante diversificar el consumo de chocolate a través de otros productos que sean de alta demanda en el mercado. El objetivo del trabajo fue elaborar un yogur con chocolate y evaluar las características fisicoquímicas, sensoriales, proximales y microbiológicas durante el almacenamiento en refrigeración. Para realizar la investigación se elaboró yogur en dos concentraciones,uno de ellos contenía chocolate y la otra sacarosa. Los dos tratamientos se empacaron en recipientes plástico y se evaluaron durante 30 días en condiciones de refrigeración. Durante este tiempo se evaluó pH, acidez, sinéresis, evaluación sensorial, análisis proximal y recuento de bacterias ácido lácticas Los resultados indicaron que el valor final de pH, acidez y sinéresis fue 4,27%; 0,95% y 13% respectivamente. Sensorialmente el yogur con chocolate tuvo características relevantes con calificaciones por encima de 4 sobre 5, para el análisis proximal el yogur con chocolate tuvo un valor de 3,2% superior al yogur con sacarosa. El recuento de bacterias acido lácticas indicó un aumento para las muestras con chocolate. Basándose en las características fisicoquímicas, sensoriales, proximales y microbiológicas se sugiere que la adición de chocolate puede ser considerado potencialmente un ingrediente para elaboración de yogur.

La salinización del suelo se considera como uno de los factores ambientales limitantes del crecimiento y productividad de los cultivos en el mundo, principalmente en regiones áridas y semiáridas. Una alternativa para aliviar el estrés causado por este factor abiótico es el uso de Rizobacterias Promotoras de Crecimiento Vegetal (RPCV), las cuales pueden contribuir en el crecimiento de las plantas a través de sus múltiples funciones. El objetivo de la investigación fue realizar el aislamiento, caracterización y determinación del efecto de bacterias de vida libre halotolerantes asociadas a Acacia decurrens. Los microorganismos se caracterizaron bioquímicamente a partir de la producción de amonio, determinación de la actividad de celulosa, producción de exopolisacáridos, producción de Índoles totales, determinación cuantitativa de solubilización de fósforo y genéticamente con el 16S rRNA. Bajo condiciones de invernadero se evaluó el efecto de los microorganismos seleccionados sobre la promoción de crecimiento de Acacia decurrens a partir de variables morfométricas. Los resultados demostraron que los nueve aislamientos en estudio presentaron en general una buena actividad metabólica excepto los aislamientos ACSA12 y ACSA19 que no expresaron producción celulolítica. La respuesta de la planta evidenció que los aislamientos T4, T5 y T7 incrementaron de manera significativa la biomasa y desarrollo de la misma (p0.05). Los aislamientos fueron identificados genéticamente como Pantoea deleyi ACSA12, Enterobacter amnigenus ACSA14 y Serratia liquefaciens ACSA19.

El presente trabajo se realizó con la finalidad de evaluar una fuente no convencional de harina y almidón. Se caracterizó fisicoquímicamente mediante análisis proximal, calorimetría diferencial de barrido (DSC), análisis termogravimétrico (TGA); microscopía electrónica de barrido (SEM); difracción de rayos X (XRD) y análisis de viscosidad rápida (RVA). En el análisis proximal la harina arrojó: humedad 7,43%, proteína 2,57%, grasa 0,20%, cenizas 2,43%; mientras que el almidón: humedad 8,7%, proteína 1,53%, grasa 0,12%, cenizas 1,07%, fibra 1,67%. El análisis de DSC en la harina y almidón presentaron temperaturas de gelatinización y entalpias relativamente bajas 69,3°C y 2,02 J/g y 54,7°C y 2,4 J/g respectivamente. El análisis de TGA en la harina y el almidón mostraron temperaturas de descomposición de los compuestos de bajo peso molecular a los 286,1°C y 230°C. Los gránulos de almidón mostraron formas elípticas, con una longitud y diámetros promedio de 39 µm y 24 µm. Los difractogramas de rayos X arrojaron un patrón de difracción tipo C para la harina y para el almidón. La harina y el almidón presentaron, viscosidades de 1132 cP y 2068 cP, con temperaturas de empastamiento de 75,1 y 76,8°C; una viscosidad final de 1121 cP y 2530 cP; Breakdown de 18 y 285 cP; Secback de 107 y 747 cP. La evaluación fisicoquímica y térmica de las harinas y del almidón, presentaron características térmicas atractivas para reducción de costos energéticos en diferentes procesos agroindustriales.

El proceso de certificación de las empresas productoras de hortalizas en la Región Noroeste de México, se hace más necesario, si se quiere mejorar la competitividad, como respuesta a exigencias mismas del mercado. Este trabajo busca hacer una medición cuantitativa de la Disposición a Certificarse por parte de los productores, lo cual implica asumir costos adicionales pero que luego se convierten en ventajas comparativas en la medida que los productos puedan llegar al mercado. Mediante el uso del método de valoración contingente (VC), técnicas de regresión logística con estimación de parámetros usando máxima verosimilitud, se concluye que las variables aplicación de estándares especialmente de calidad e inocuidad, trabajar bajo agricultura por contrato influyen positivamente en la Disposición a Certificar la producción; mientras que la experiencia como productor de hortalizas, influyen negativamente.