Cocoa is a food product with sensory and organoleptic attributes that depends on postharvest processes such as fermentation. This process affects not only the sensory profile, but also chemical reactions and therefore, the quality of the product. Hence, the aim of this study is to carry out a chemical and sensory characterization of cocoa (Theobroma cacao L.) samples from different cocoa farms in the department of Huila, Colombia. Moreover, a bromatological analysis was performed, secondary metabolites (caffeine and theobromine) and total polyphenols were determined, as well as volatile fraction compounds using gas chromatography by solid phase microextraction in the headspace mode (HS-SPME); finally, the samples were classified (acceptable, unpleasant and contaminated) according to a tasting panel. In general, bromatological characteristics of cocoa samples showed acceptable levels, presence of special volatile compounds (linalool and linalool oxide) that affected sensory attributes (floral). Likewise, levels of caffeine and theobromine had adequate levels that resulted in bitter taste. A relationship was found between volatile fraction compounds and bromatological analysis variables, secondary metabolites and total polyphenols that affected the quality of the product.Keywords: bromatological analysis, secondary metabolites, polyphenols, volatile fraction compounds, sensory analysis, sensory attributes. ResumenEl cacao es un alimento que posee atributos sensoriales y organolépticos que dependen de procesos de poscosecha como la fermentación. Este proceso además de afectar el perfil sensorial, incide sobre las reacciones químicas y por consiguiente, en la calidad del producto. Por lo anterior, el objetivo de este estudio es realizar una caracterización química y sensorial de muestras de cacao (Theobroma cacao L.) de diferentes fincas cacaoteras en el departamento del Huila, Colombia. Se realizó además un análisis bromatológico, se determinaron los metabolitos secundarios (cafeína y teobromina) y polifenoles totales, así como compuestos de la fracción volátil utilizando cromatografía de gases por microextracción en fase sólida en el modo headspace (HS-SPME); por último, se realizó una clasificación de las muestras (aceptable, desagradable y contaminada) resultado de un panel de catación. En general, se encontraron muestras de cacao con características bromatológicas en niveles aceptables, presencia de compuestos volátiles especiales (linalool y oxido de linalool) que incidieron en los atributos sensoriales (floral). Así mismo, niveles de cafeína y teobromina en un nivel adecuado que se tradujo en el sabor amargo. Se encontró una relación entre los compuestos de la fracción volátil y las variables del análisis bromatológico, metabolitos secundarios y polifenoles totales que incidieron en la calidad del producto.

Changes in coverage affect the activity of soil's microbial communities, affecting the carbon and nitrogen cycle. The variability of biochemical properties in different coverages (native forest, forest plantation, silvopastoral system and pasture) located in the northwest of the Colombian Amazon was evaluated. Edaphic properties were determined as: organic carbon (OC), total nitrogen (TN), microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN) using the fumigation method. A significant effect was found to land use × depth interaction for the variables moisture, pH, CO and MBC/OC ratio (p < 0.05), while MBC and dCO 2 showed differences only for land use and NT, MBN and MBN/TN ratio at depth (p < 0.05). In general, when modifying the soil cover, changes were made in the chemical properties that affected the microbial activity.

The objective of this study was to evaluate photosynthetic performance based on gas exchange traits, chlorophyll a fluorescence, and leaf water potential (ΨL) in nine Hevea brasiliensis genotypes from the ECC-1 (Élite Caquetá Colombia) selection and the cultivar IAN 873 (control) in response to different climatic (semi-humid warm and humid warm climates), seasonal (dry and rainy periods), and hourly (3:00 to 18:00) variations that can generate stress in the early growth stage (two-year-old plants) in two large-scale clonal trials in the Colombian Amazon. The photosynthetic performance in 60% of the Colombian genotypes was slightly affected under the conditions with less water availability (dry period, semi-humid warm site, and between 9:00 and 15:00 h), as compared with IAN 873, whose affectation was moderate in terms of photosynthesis rates, but its water conservation strategy was strongly affected. The ECC 90, ECC 83, and ECC 73 genotypes had the best photosynthetic performance under conditions of greater water limitation, and ECC 35, and ECC 64 had a higher water status based on the leaf water potential, with intermediate photosynthetic performance. This germplasm has a high potential for selection in rubber tree breeding programs in future scenarios of climate change in the Colombian Amazon.