Quality enhancement of chilled fish by including alga Bifurcaria bifurcata extract in the icing medium

9 páginas, 4 tablasBifurcaria bifurcata is a widely extended brown macroalga, whose antimicrobial and antioxidant properties have previously been described. In this study, ethanolic extracts of B. bifurcata were included in the icing medium employed for the chilled storage of megrim (Lepidorhombus whiffiagonis). For it, two different concentrations of this brown macroalga extract (0.67 and 2.50 g lyophilized alga L−1 aqueous solution; B-1 and B-2 batches, respectively) were tested for a 14-day storage. The effect of the alga extract was compared with a counterpart batch stored in traditional ice prepared only from water (B-0 batch). Significant (p < 0.05) inhibitions of microbial activity (aerobes, psychrotrophs, lipolytic bacteria, proteolytic bacteria and Enterobacteriaceae) as well as of pH and trimethylamine formation were observed as a result of the incorporation of the alga extract in the icing medium, being this effect especially relevant in the B-2 batch. Concerning lipid damage development, a significantly (p < 0.05) lower formation of free fatty acids (lipid hydrolysis development) and of fluorescent compounds (tertiary lipid oxidation development) in samples corresponding to both alga-including batches could also be observed; this inhibitory effect was more intense in fish belonging to the B-2 batch. The icing medium proposed in this work constitutes a promising strategy in order to apply algae extracts to enhance fish quality retention during the different steps of storage and commercialization of marine speciesThis work was supported by the Consejo Superior de Investigaciones Científicas (CSIC; Spain) through the project PIE 201370E001Peer reviewe

On-board quality preservation of megrim (Lepidorhombus whiffiagonis) by a novel ozonised-slurry ice system

6 páginas, 3 tablas.-- The final publication is available at www.springerlink.comThe use of a combined ozonised-slurry ice system was investigated as a new refrigeration system for the on-board storage of megrim (Lepidorhombus whiffiagonis), a fish species that is usually stored aboard fishing vessels for 1 to 2 weeks. The time elapsed between the catch and unloading at the harbour affects its quality and commercial value directly. Microbiological, chemical and sensory analyses were carried out in megrim after 2 weeks of onboard storage in ozonised slurry ice, slurry ice or flake ice, and for an additional period of 6 days. Sensory analyses revealed that megrim specimens stored in ozonised slurry ice (oSI600 batch) maintained A quality even after 20 days of storage, while counterpart batches stored in flake ice showed B quality at unloading, after 14 days of on-board storage. Storage in ozonised slurry ice (oSI600 batch) also led to significantly (p<0.05) lower counts of aerobic mesophiles, psychrotrophic bacteria, Enterobacteriaceae and proteolytic microorganisms in megrim muscle as compared with flake ice. Biochemical analyses revealed that the use of ozonised-slurry ice or slurry ice alone slowed down the formation of total volatile base-nitrogen (TVBN) and trimethylamine-nitrogen (TMA-N) in comparison with storage in flake ice, also allowing a better control of pH. Lipid hydrolysis and oxidation events also occurred at a lower rate in the ozonised-slurry ice and slurry ice batches than in the flake ice batch. The present study demonstrates that the combination of slurry ice and ozone for the on-board storage of megrim is advisable, thus improving the quality and extending the shelf life of this fish species.This work was supported through a project grant by the Secretar´ıa Xeral de I+D from the Xunta de Galicia (Project PGIDIT04TAL015E).Peer reviewe

Effect of jumbo squid (Dosidicus gigas) skin extract on the microbial activity in chilled mackerel (Scomber scombrus)

6 páginas, 4 tablas, 2 figurasDuring the industrial processing of jumbo squid (Dosidicus gigas), large amounts of by-products containing biological active compounds are generated. In this study, aqueous solutions including acetic acid-ethanol extracts of jumbo squid skin (JSS) were tested at three different concentrations as icing media. The effects of the JSS extracts on the quality evolution of chilled mackerel (Scomber scombrus) were monitored. A significant inhibition (p < 0.05) of microbial activity was determined in the fish batch corresponding to the icing condition including the highest JSS concentration. Additionally, fish specimens corresponding to batches including any of the JSS concentrations tested showed lower (p < 0.05) proteolytic counts and pH values than control mackerel. Sensory analysis revealed a marked shelf life extension in chilled mackerel stored in ice including the highest JSS concentration; specimens from such batch were found to be still acceptable after 13 days of storage, while all other mackerel batches were rejectable. The marked microbial activity inhibition observed could be explained on the basis of the presence in ice of lipophilic compounds obtained by acetic acid-ethanol extraction of JSSThis work was supported by the CONACYT-Mexico grant 154046 and the Consejo Superior de Investigaciones Científicas (CSIC) through Research Project PIE 201370E001Peer reviewe

Estudio de los efectos de algunos psicotropos en el test "Open Field"

Por medio del test "opcn-field" se ha analizado el comportamiento de ratas tratadas con diversos psicotropos ncurolépt icos. antidcpresivos, tranquilizntes, barbitú ricos, psicoana l~pt icos) y asociaciones, entre las que figura la de un IMAO (nialamida) y 5-hidroxitriptofano, precusor de la serotonina cerebral. De los resultados obtenidos se deduce que los neurolépticos dieron lugar a una marcada reducción de la motilidad, en tanto que el clordiacepóxido y el fenobarbilal produjeron el efecto con· trario, probablemente como expresión de un efecto ansiolítico notable. La asociación de nialamida y 5-hidroxitriptofano dió lugar a una reducción muy significativa de la deambulación de las ratas tratadas, sugiriéndose una participación de la serotonina en los circuitos moduladores de la actividad de las ratas. Este descenso de movilidad fue hallado, asimtsmo, con la imipramina, r~lacio nándose también, este fenómeno, con una posible intensificación de sistemas serotoninérgicos. En cuanto a la intervención de los psicotropos sobre las estereotipias y las emisiones de bolos fecales, no se han encontrado resultados capaces de informar con eficacia, sobre la utilidad de estos dos parámetros como medida para la "emotividad"

Aplicación de hielo incluyendo conservantes naturales para la mejora de la calidad de especies marinas refrigeradas

6 páginas, 4 figurasComo resultado de la creciente demanda de productos marinos frescos de alta calidad, la tecnología de alimentos ha desarrollado una gran diversidad de estrategias novedosas de refrigeración que han contribuido al desarrollo continuado y a la innovación en el sector. En este trabajo se describe la actividad llevada a cabo en los últimos años en nuestro grupo de trabajo. En él, se desarrolló una estrategia nueva consistente en emplear como medio de refrigeración hielo preparado a partir de disoluciones acuosas incluyendo componentes conservantes naturales de distinta procedencia (extractos vegetales, ácidos orgánicos de pequeño tamaño y extractos de macroalgas)Los experimentos fueron financiados por la Secretaría Xeral de I+D de la Xunta de Galicia (Galicia, España) (Proyecto 10 TAL 018E), el Consejo Superior de Investigaciones Científicas (CSIC; Proyecto PIE 201370E001) y el Programa de Cooperación Hispano-Chileno “Universidad de Chile-Consejo Superior de Investigaciones Científicas (CSIC) (Proyecto 2004 CL 0038).Peer reviewe

Sigatoka Negra em Rondônia.

O presente trabalho visa apresentar dados sobre a ocorrência da sigatoka negra nos diferentes municípios do Estado de Rondônia, tendo como base os dados obtidos a partir do mapeamento da ocorrência de sigatoka negra realizado pela Embrapa Rondônia em parceria com a Agência de Defesa Agrossilvopastoril de Rondônia - Idaron, o qual teve início em 2004. Os dados apresentados representam coletas realizadas no período de janeiro de 2004 a junho de 2007 por técnicos da agência Idaron nos diferentes municípios do Estado.bitstream/CPAF-RO-2009-09/12229/1/cot324_sigatokanegra.pd

Tratamiento por Electrocoagulación para la remoción de índigo carmín presente en agua

En el presente estudio se evaluaron las condiciones óptimas del proceso de electrocoagulación (EC) para su aplicación en la remoción del colorante índigo carmín(IC) presente en agua. Se utilizaron soluciones acuosas de diferentes concentraciones iniciales de 100, 200 y 300 mg/L del colorante. Se determinó la densidad de corriente (DC) óptima para cada una de las concentraciones de partida. Se encontró que, al aumentar la concentración inicial del índigo carmín, la DC óptima utilizada fue mayor, para un tiempo de tratamiento de 40 minutos. Los porcentajes de remoción de color obtenidos fueron 65, 61 y 54% partiendo de concentraciones inicial de 100, 200 y 300 mg/L respectivamente

In Situ Structural Characterization of a Recombinant Protein in Native Escherichia coli Membranes with Solid-State Magic-Angle-Spinning NMR

The feasibility of using solid-state MAS NMR for in situ structural characterization of the LR11 (sorLA) transmembrane domain in native Escherichia coli (E. coli) membranes is presented. LR11 interacts with the human amyloid precursor protein (APP), a central player in the pathology of Alzheimer's disease. The background signals from E. coli lipids and membrane proteins had only minor effects on LR11 TM resonances. Approximately 50% of the LR11 TM residues were assigned by using 13C PARIS data. These assignments allow comparisons of the secondary structure of LR11 TM in native membrane environments and in commonly used membrane mimics (e.g. micelles). In situ spectroscopy bypasses several obstacles in the preparation of membrane proteins for structural analysis, and offers an opportunity to investigate the consequences of membrane heterogeneity, bilayer asymmetry, chemical gradients, and macromolecular crowding on the protein structure

Levantamento da ocorrência do moko da bananeira em Rondônia.

O presente trabalho visa apresentar dados sobre o levantamento da ocorrência do moko nos diferentes municípios do Estado de Rondônia, tendo como base as coletas de amostras de bananais, realizado pela Agência de Defesa Agrossilvopastoril de Rondônia ? Idaron, em parceria com a Embrapa Rondônia, entre os anos de 2004 e 2007.bitstream/CPAF-RO-2009-09/12208/1/cot323_mokodabananeira.pdfAngela M. L. Nunes, Embrapa Rondônia (In memorian)