Influencia del procesamiento del fruto de membrillo (Cydonia Oblonga Miller) en el contenido de polifenoles y actividad antioxidante del mismo.

Los polifenoles son metabolitos secundarios presentes en gran proporción en las frutas, en su mayoría representados por los flavonoides y ácidos fenólicos. El creciente interés por estas sustancias es principalmente debido a su capacidad antioxidante y la asociación entre su consumo y la prevención de algunas enfermedades. Entre las frutas, el membrillo es una importante fuente de componentes que promueven la salud, tales como compuestos fenólicos. Si bien el membrillo no se consume fresco debido a su dureza, amargor y astringencia, es muy apreciado como materia prima para la producción de dulces y jaleas. El objetivo de este trabajo fue evaluar la propiedad antioxidante del fruto de membrillo, su dulce y los productos intermediarios de su elaboración, con el fin de estudiar el efecto del procesado térmico en las características nutricionales del mismo. Se analizaron el fruto (pulpa+piel), la mezcla cruda (pulpa+piel+azúcar) y el dulce regular y el reducido en carbohidratos. Se midió el contenido de polifenoles totales (PT), perfil de polifenoles por HPLC-DAD-MSMS y la actividad antioxidante in vitro por las técnicas DPPH (capacidad de atrapamiento de radicales libres) y FRAP (poder reductor). Todas las muestras analizadas presentaron un alto contenido de polifenoles en un rango de 200-500 mg ac. gálico/100g muestra (futo, mezcla cruda, dulce). Se demostró la actividad antioxidante in vitro por ambos métodos en todas las muestras. Los valores obtenidos variaron entre 400 y 1500 μmol TROLOX/100g muestra (futo, mezcla cruda, dulce). Tanto para la línea regular como la reducido en carbohidratos se mantuvo el contenido de polifenoles desde el fruto al dulce, conteniendo el regular 370 mg de ác. gálico/100 g de dulce y el light 184 mg ác. gálico/100g de dulce. Por otro lado se lograron identificar 16 compuestos polifenólicos, siendo los mayoritarios los ácidos cafeoil-quínicos, seguidos por los derivados del ácido cumárico, catequina y quercetina. La proporción de los distintos compuestos también se mantuvo desde el fruto al dulce, lo que significa que el procesado térmico no afecta cuantitativamente ni cualitativamente el contenido de polifenoles. Con respecto a la capacidad antioxidante determinada por DPPH y FRAP, como era de esperarse al mantenerse el contenido de polifenoles, no hubo tampoco pérdida de la actividad debido al procesamiento del membrillo. Los resultados obtenidos demuestran que el dulce de membrillo realiza un aporte importante de antioxidantes en la dieta, y además que no existe perdida en la calidad nutricional debido al procesado térmico.publishedVersio

Pollination and Predation Limit Fruit Set in a Shrub, Bourreria succulents (Boraginaceae), after Hurricanes on San Salvador Island, Bahamas 1

Hurricanes have been assumed to reduce the reproduction of plants, either directly by leaf stripping and stress or indirectly by reducing pollinators. I examined the pollination and fruit set of a common shrub, Bourreria succulenta , after hurricanes on San Salvador island, Bahamas. Contrary to the assumption of resource limitation, B. succulenta showed unusually prolific flowering after Hurricane Lili stripped leaves from most of the plants in October 1996. I predicted that the abundant flowering would saturate pollinators and that fruit set would be pollination-limited. Fruit set was strongly pollination-limited by 71 percent. Butterflies are probably the major pollinators and were present at the site, but they rarely visited B. succulenta flowers even though flowers were brimming with nectar. Nectarivorous birds (Bananaquits and Bahama Wbodstars) visit B. succulenta flowers, but their populations were decimated by Hurricane Lili and they rarely visited flowers during this time. Fruit set was also severely predation-limited; a moth caterpillar (Gelechiidae) was extremely abundant and ate buds, flowers, and fruits, causing a further 68 percent reduction in fruit set. Together, pollination limitation and predation limitation reduced fruit set to only 7 percent or less. Predation was also intense in 1999 after Hurricane Floyd and resulted in 11 percent fruit set or less. Whether or not hurricanes were the cause of limited pollinators or abundant predators, the resulting low fruit set could have population effects because hurricanes can provide opportunities for the recruitment of new plants. These results emphasize that understanding plant–animal interactions may be necessary for predicting the effects of hurricanes on plant reproductive success, which may affect subsequent recruitment. Species on small islands like San Salvador (150 km 2 ) with relatively few species may be especially vulnerable to environmental disturbances such as hurricanes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75721/1/j.1744-7429.2001.tb00184.x.pd

Meta-omics approaches to understand and improve wastewater treatment systems

Biological treatment of wastewaters depends on microbial processes, usually carried out by mixed microbial communities. Environmental and operational factors can affect microorganisms and/or impact microbial community function, and this has repercussion in bioreactor performance. Novel high-throughput molecular methods (metagenomics, metatranscriptomics, metaproteomics, metabolomics) are providing detailed knowledge on the microorganisms governing wastewater treatment systems and on their metabolic capabilities. The genomes of uncultured microbes with key roles in wastewater treatment plants (WWTP), such as the polyphosphate-accumulating microorganism Candidatus Accumulibacter phosphatis, the nitrite oxidizer Candidatus Nitrospira defluvii or the anammox bacterium Candidatus Kuenenia stuttgartiensis are now available through metagenomic studies. Metagenomics allows to genetically characterize full-scale WWTP and provides information on the lifestyles and physiology of key microorganisms for wastewater treatment. Integrating metagenomic data of microorganisms with metatranscriptomic, metaproteomic and metabolomic information provides a better understanding of the microbial responses to perturbations or environmental variations. Data integration may allow the creation of predictive behavior models of wastewater ecosystems, which could help in an improved exploitation of microbial processes. This review discusses the impact of meta-omic approaches on the understanding of wastewater treatment processes, and the implications of these methods for the optimization and design of wastewater treatment bioreactors.Research was supported by the Spanish Ministry of Education and Science (Contract Project CTQ2007-64324 and CONSOLIDER-CSD 2007-00055) and the Regional Government of Castilla y Leon (Ref. VA038A07). Research of AJMS is supported by the European Research Council (Grant 323009

Solidago gymnospermoides in Illinois

Volume: 70Start Page: 287End Page: 28

A note on Bauhinia hagenbeckii Harms

Volume: 17Start Page: 245End Page: 24

ENUMERATION AND TYPIFICATION OF GENERA IN TRIBE CERCIDEAE

Volume: 78Start Page: 750End Page: 76

Bauhinia lunarioides: a misapplied name

Volume: 78Start Page: 546End Page: 54