Evaluación sensorial de diferentes presentaciones comerciales de dorada (Sparus aurata L) de acuicultura / Sensory analysis of different aquaculture gilthead sea bream (Sparus aurata L) commercial presentations

El análisis o evaluación sensorial, se puede definir como el análisis de los alimentos a través de los sentidos. Desde la antigüedad se ha utilizado la valoración sensorial para aceptar o rechazar los alimentos, así como para asignarle un determinado valor comercial. El análisis sensorial presenta dos grandes ventajas: la rapidez y la sencillez, sin embargo, las sensaciones que motivan al rechazo o aceptación varían con el tiempo y el momento que se perciben, dependiendo tanto de la persona como del entorno, con lo que es necesario objetivar y normalizar los términos y las condiciones que puedan influir en las determinaciones. En el presente estudio se llevó a cabo el análisis sensorial de cuatro presentaciones diferentes de dorada almacenadas en hielo: enteras, fileteadas, fileteadas y envasadas al vacío, y marinadas con zumo de limón y envasadas al vacío. El estudio se realizó para determinar el momento en el cual los distintos tipos de muestras eran rechazadas organolépticamente. Para ello un panel de catadores semientrenados evaluaron los atributos de apariencia, olor, flavor y textura, en los filetes de dorada cocinados, utilizando una escala puntuada. En las cuatro presentaciones comerciales, las puntuaciones otorgadas por el panel para la frescura decrecen linealmente a medida que pasan los días de permanencia en hielo. Los miembros del panel de catadores consideraron organolépticamente inaceptables las doradas enteras, las fileteadas y las fileteadas al vacío, en el día 22 de almacenamiento en hielo, sin embargo, las doradas marinadas no alcanzaron esta consideración en los 22 días que duró el estudio (AU)

The analysis or sensory test may be defined as an analysis of food by means of the senses. Such sensory evaluations have been used from ancient times to accept or reject food, as well as to designate its commercial value. Sensory analysis provides two important advantages: it is quick and it is simple. However, the senses which give rise to acceptance or rejection do vary over time and at the moment of perception. This depends as much on the person as on the environment. A reliable measure requires objectivity and normative regulation of terms and conditions that can influence specific evaluations. The current study has carried out sensory analysis of four different githhead sea bream presentations (whole, fillets, vacuum packed fillets, and marinated in lemon juice and vacuum packed fillets). The study was done as a quality test in order to determine the moment in which the fish is organoleptically rejected. In the four presentations, the scores given for freshness, decreased linearly according to time spent in ice. The taste panel members found the whole, the filleted and the vacuum filleted sea bream organoleptically unacceptable by the 22nd day on ice. Nevertheless, marinated sea bream were not so considered by the 22nd day (AU)

Co-occurrence of viral and bacterial pathogens in disease outbreaks affecting newly cultured sparid fish

Several microbial disease outbreaks in farm stocks of newly cultured sparid fish species, such as common seabream, redbanded seabream, and white seabream, were recorded from 2004 to 2006. This study describes the isolation and characterization of the potential causative agents, either bacteria or viruses, of these outbreaks. The isolated bacterial strains were characterized according to traditional taxonomical analyses and sequencing of a 16S rDNA fragment. Most bacteria were identified as Vibrio spp. and Photobacterium damselae subsp. damselae. The development of cytopathic effects (CPE) on different fish cell lines, the application of specific nested-PCR tests for infectious pancreatic necrosis virus (IPNV), viral nervous necrosis virus (VNNV) and viral hemorrhagic septicemia virus (VHSV), and subsequent sequence analyses were used for virus detection and identification. VNNV, related to the striped jack neural necrosis virus (SJNNV) genotype, and VHSV, related to the genotype Ia, were the only viruses detected. VNNV was isolated from the three fish species under study in five different outbreaks, whereas VHSV was isolated from common seabream and white seabream during two of these outbreaks. IPNV was not detected in any case (AU)

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Economías de escala en las explotaciones de engorde de dorada (Sparus Aurata) en jaulas flotantes en el Mediterráneo / Economies of scale for ongrowing gilthead sea bream (Sparus aurata) on off shore cages in the Mediterranean Sea

En los últimos años se ha confi rmado el dinamismo y la expansión del sector de la acuicultura marina en generaly de la establecida en el mediterráneo en particular, destacando la producción de determinadas especies queaún no han llegado a saturar el mercado (García García et al., 2001). En el caso de las explotaciones de engordeen jaulas en mar abierto de dorada en el mediterráneo, en la dirección apuntada de su continuo y sostenido crecimientorespecto a la capacidad productiva, existen escasos trabajos que expliquen esta tendencia justifi cando laexistencia de economías de escala (Gasca-Leyva et al., 2001); en esta dirección este trabajo pretende describir loscostes asociados a varios tamaños de explotación y analizar su evolución e infl uencia sobre los costes medios

Sea aquaculture is confi rmed as a dynamic and expansive industry both in general, and particularly in theMediterranean Sea, where it can be pointed out certain species that have not still fl ooded the market (GarcíaGarcía, 2001). Gilthead seabream ongrowing farms in the Mediterranean on offshore cages have also a continuousand sustained growth of their productive capability. There is a scarcity of papers explaining this tendencyand justifying the existence of scales of economy (Gasca-Leyva et al., 2001). This paper contributes to thedescription of the associated costs to different farm sizes, and the analysis of their evolution and infl uence on the average costs

Hydrophobicity and adhesion to fish cells and mucus of Vibrio strains isolated from infected fish

The hydrophobicity of 44 Vibrio strains isolated from cultured, diseased gilt-head sea bream (Sparus aurata) was determined. Three different methods were used: (1) microbial adhesion to hydrocarbons (MATH), either with phosphate buffer or with phosphate urea magnesium sulfate (PUM) buffer, (2) aggregation in the presence of salt solutions (SAT), and (3) adhesion to nitrocellulose filters (NCF). The results show that experimental conditions exerted a significant influence on hydrophobicity. Thus, Kendall rank coefficients showed the presence of correlation only for SAT and NCF, and for SAT and the MATH assay with PUM buffer. Moreover, no relationships were observed between the bacterial hydrophobicity estimated with the methods mentioned above and the ability of the strains to adhere to fish mucus or cells. These results indicate that adhesion of pathogenic Vibrio strains to host surfaces is mediated mainly by specific receptor interactions, instead of by hydrophobic interactions (AU)

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