Impacto de la actividad antropogénica en el suelo de la reserva de la biosfera “el triunfoâ€, Chiapas (México)

The impact of human activity on the soil of “El Triunfo†Biosphere Reserve, Chiapas, was studied. For this purpose, the values of 14 parameters were determined throughout a year: six physical-chemical and eight biochemical, in forest, coffee plantation, pasture and milpa soils. The values of the parameters in the forest soil were significantly different from those in the coffee plantation, pasture and milpa soils. On the basis of the forest soil, it was considered that human activity altered the soil quality negatively. To have clarity about the level of impact, a scale of 0.0 to 5.0 was suggested, identified as the Soil Deterioration Index (SDI), and the procedure was developed to determine it in the soils with human alteration. The milpa soil had the highest SDI value, placing it in the range of high degradation. The coffee plantation and pasture soils were found in the range of medium degradation. The procedure and scale of SDI was reinforced by discriminant analysis.Se estudió el impacto de la actividad humana en el suelo de la Reserva de la Biosfera “El Triunfoâ€, Chiapas. Para ello se determinaron, a lo largo de un año, los valores de 14 parámetros, seis físico-químicos y ocho bioquímicos, en suelos de bosque, cafetal, pastizal y milpa. Los valores de los parámetros en el suelo del bosque fueron diferentes significativamente a los de cafetal, pastizal y milpa. Tomando como base el suelo de bosque se consideró que la actividad humana alteró negativamente la calidad del suelo. Para tener claridad del nivel de impacto se propuso una escala, de 0.0 a 5.0, identificada como Ãndice de Deterioro del Suelo (IDS), y se desarrolló el procedimiento para determinarlo en los suelos con alteración humana. El suelo de milpa tuvo el mayor valor de IDS, ubicándose en el rango de alta degradación. Los suelos de cafetal y de pastizal se ubicaron en el rango de mediana degradación. El procedimiento y escala de IDS se reforzó a través del análisis discriminante

Does Biodiesel from Jatropha Curcas Represent a Sustainable Alternative Energy Source?

Various government agencies around the world have proposed vegetable oils and their conversion to biodiesel as a renewable alternative to fossil fuels. Due to its adaptability to marginal soils and environments, the cultivation of Jatropha curcas is frequently mentioned as the best option for producing biodiesel. In the present work the current situation of proven and potential reserves of fossil fuel, and the production and consumption model for the same are analyzed, in order to later review the sustainability of the production process which begins with the cultivation of J. curcas, and culminates with the consumption of biodiesel. A review of the following topics is proposed in order to improve the sustainability of the process: areas destined for cultivation, use of external (chemical) inputs in cultivation, processes for converting the vegetable oil to biodiesel, and, above all, the location for ultimate consumption of the biofuel

Alcaloides y polifenoles del cacao, mecanismos que regulan su biosíntesis y sus implicaciones en el sabor y aroma

El sabor y aroma de los granos de cacao (Theobroma cacao L.) fueron las principales razones que promovieron su domesticación y uso alimentario por los pueblos precolombinos de Mesoamérica. Incluso hoy día, la calidad sensorial determina la clasificación entre cacaos finos y a granel. Muchos compuestos químicos de las almendras son responsables de la calidad sensorial, pero sobresalen los polifenoles y los alcaloides, compuestos que de manera directa inciden en el sabor y palatabilidad de las almendras y de manera indirecta sobre los precursores de aroma. Los alcaloides están asociados con el amargor. Su concentración está relacionada con la variedad y se modifica con el procesamiento. Los polifenoles son responsables, junto con otras moléculas de la astringencia (poco deseable en chocolates), pero también de propiedades antioxidantes deseables por los consumidores. En esta revisión se abordan aspectos de la biosíntesis de estas importantes moléculas en las almendras de cacao, de las implicaciones en el sabor y aroma, así como los cambios que ocurren durante el procesamiento de las mismas.The flavor and aroma of cacao (Theobroma cacao) beans were the main reasons that promoted its domestication and food-use by pre-Columbian peoples of Mesoamerica. Polyphenols and alkaloids are compounds that directly affect the flavor of the cocoa beans and indirectly on the flavor precursors. The alkaloids are associated with bitterness; its concentration is related to the cultivar and its modifying through the processing. Polyphenols molecules are responsible together with other molecules of the astringency (not desirable in chocolate), but also are responsible for antioxidant properties, very desirable by consumers. This review focuses on aspects of the biosynthesis of these important molecules in cocoa beans as well as implications in taste and flavor. The changes of these molecules that occur during processing are also approached

Alcaloides y polifenoles del cacao, mecanismos que regulan su biosíntesis y sus implicaciones en el sabor y aroma

El sabor y aroma de los granos de cacao (Theobroma cacao L.) fueron las principales razones que promovieron su domesticación y uso alimentario por los pueblos precolombinos de Mesoamérica. Incluso hoy día, la calidad sensorial determina la clasificación entre cacaos finos y a granel. Muchos compuestos químicos de las almendras son responsables de la calidad sensorial, pero sobresalen los polifenoles y los alcaloides, compuestos que de manera directa inciden en el sabor y palatabilidad de las almendras y de manera indirecta sobre los precursores de aroma. Los alcaloides están asociados con el amargor. Su concentración está relacionada con la variedad y se modifica con el procesamiento. Los polifenoles son responsables, junto con otras moléculas de la astringencia (poco deseable en chocolates), pero también de propiedades antioxidantes deseables por los consumidores. En esta revisión se abordan aspectos de la biosíntesis de estas importantes moléculas en las almendras de cacao, de las implicaciones en el sabor y aroma, así como los cambios que ocurren durante el procesamiento de las mismas

Films of Chitosan and Aloe vera for Maintaining the Viability and Antifungal Activity of Lactobacillus paracasei TEP6

The present study aimed to evaluate the effect of Aloe vera addition on the viability and antifungal activity of TEP6 (Lactobacillus paracasei) bacteria immobilized on chitosan films for 28 days. Different chitosan and A. vera proportions and carbon sources at several pH values were tested as formulations for supporting the microorganism. Bacterial viability was maintained in freshly made films, with values of 10.4, 10.8 and 10.9 log CFU·g−1 for the formulations containing 70% (T11), 100% (T8) and 100% (T16) of A. vera, respectively. The same formulations (T8, T11 and T16) maintained bacterial viability for 14 days of film storage with a loss to values of 9.5 log CFU·g−1. By applying a quarter fraction 25–2 experimental design with an array of five factors, the factors with the greatest influence on viability and antifungal activity were determined. The optimal conditions for viability were the formulation with 100% A. vera, pH 4.5 and 0.1 M glucose. The antifungal activity of fresh films was influenced by the formulation with 10 g·L−1 glycerol and 100% A. vera, showing a 60% inhibition of fungal (Colletotrichum gloeosporioides) growth. The films developed in this study may have the potential to be used as coatings on vegetal products susceptible to attack by Colletotrichum gloesporioides

Does Biodiesel from Jatropha Curcas Represent a Sustainable Alternative Energy Source?

Various government agencies around the world have proposed vegetable oils and their conversion to biodiesel as a renewable alternative to fossil fuels. Due to its adaptability to marginal soils and environments, the cultivation of Jatropha curcas is frequently mentioned as the best option for producing biodiesel. In the present work the current situation of proven and potential reserves of fossil fuel, and the production and consumption model for the same are analyzed, in order to later review the sustainability of the production process which begins with the cultivation of J. curcas, and culminates with the consumption of biodiesel. A review of the following topics is proposed in order to improve the sustainability of the process: areas destined for cultivation, use of external (chemical) inputs in cultivation, processes for converting the vegetable oil to biodiesel, and, above all, the location for ultimate consumption of the biofuel

Unique haplotypes of cacao trees as revealed by trnH-psbA chloroplast DNA

Cacao trees have been cultivated in Mesoamerica for at least 4,000 years. In this study, we analyzed sequence variation in the chloroplast DNA trnH-psbA intergenic spacer from 28 cacao trees from different farms in the Soconusco region in southern Mexico. Genetic relationships were established by two analysis approaches based on geographic origin (five populations) and genetic origin (based on a previous study). We identified six polymorphic sites, including five insertion/deletion (indels) types and one transversion. The overall nucleotide diversity was low for both approaches (geographic = 0.0032 and genetic = 0.0038). Conversely, we obtained moderate to high haplotype diversity (0.66 and 0.80) with 10 and 12 haplotypes, respectively. The common haplotype (H1) for both networks included cacao trees from all geographic locations (geographic approach) and four genetic groups (genetic approach). This common haplotype (ancient) derived a set of intermediate haplotypes and singletons interconnected by one or two mutational steps, which suggested directional selection and event purification from the expansion of narrow populations. Cacao trees from Soconusco region were grouped into one cluster without any evidence of subclustering based on AMOVA (FST = 0) and SAMOVA (FST = 0.04393) results. One population (Mazatán) showed a high haplotype frequency; thus, this population could be considered an important reservoir of genetic material. The indels located in the trnH-psbA intergenic spacer of cacao trees could be useful as markers for the development of DNA barcoding

Does Biodiesel from Jatropha Curcas Represent a Sustainable Alternative Energy Source?

Various government agencies around the world have proposed vegetable oils and their conversion to biodiesel as a renewable alternative to fossil fuels. Due to its adaptability to marginal soils and environments, the cultivation of Jatropha curcas is frequently mentioned as the best option for producing biodiesel. In the present work the current situation of proven and potential reserves of fossil fuel, and the production and consumption model for the same are analyzed, in order to later review the sustainability of the production process which begins with the cultivation of J. curcas , and culminates with the consumption of biodiesel. A review of the following topics is proposed in order to improve the sustainability of the process: areas destined for cultivation, use of external (chemical) inputs in cultivation, processes for converting the vegetable oil to biodiesel, and, above all, the location for ultimate consumption of the biofuel.biofuel; Jatropha curcas ; petroleum

Reproductive biology of the biofuel plant Jatropha curcas in its center of origin

In this work, we studied the main characteristics of flowering, reproductive system and diversity of pollinators for the biofuel plant Jatropha curcas (L.) in a site of tropical southeastern Mexico, within its center of origin. The plants were monoecious with inflorescences of unisexual flowers. The male flowers produced from 3062–5016 pollen grains (266–647 per anther). The plants produced fruits with both geitonogamy and xenogamy, although insect pollination significantly increased the number and quality of fruits. A high diversity of flower visiting insects (36 species) was found, of which nine were classified as efficient pollinators. The native stingless bees Scaptotrigona mexicana (Guérin-Meneville) and Trigona (Tetragonisca) angustula (Latreille) were the most frequent visitors and their presence coincided with the hours when the stigma was receptive. It is noteworthy that the female flowers open before the male flowers, favoring xenogamy, which may explain the high genetic variability reported in J. curcas for this region of the world