El glaseado incorporando hidrocoloides como alternativa en el empaque de lomo de atún (Thunnus thynnus) congelado y almacenado a -10ºC / Tuna (Thunnus thynnus) glazed with hydrocolloids as alternative of edible coatings and storaged at -10ºC

Numerosos estudios han sido enfocados a los ingredientes naturales para mantener la calidad y la vida útil de los alimentos. Los ingredientes biodegradables, tales como hidrocoloides y proteínas pueden ser utilizados para cubrir filetes de pescado con el objetivo de suprimir los cambios de calidad durante el almacenamiento en congelación. En la actualidad se han venido desarrollando empaques comestibles, como el glaseado con hidrocoloides, (gelatina, carragenina), que además de cumplir sus funciones como película protectora del alimento, son económicos, pueden ser ingeridos por el consumidor sin riesgo de toxicidad, ayudan a preservar las características organolépticas del producto, proporcionar características nutricionales y, por ser biodegradables contribuyen a la conservación del ambiente. El objetivo del presente estudio fue evaluar la incorporación de hidrocoloides al glaseado de lomos de atún como una alternativa de empaque. Cortes de atún fueron glaseados incorporándole soluciones de carragenina 0,05, y 0,15%, y gelatina al 0,5, 1%. Los cortes fueron de 15 cm3, congelados a -30ºC y glaseados con los tratamientos mencionados sumergiéndose la muestra de atún en las soluciones a 0 ºC por 30 segundos y luego almacenados a -10ºC por 0, 15 y 30 días. Los resultados del análisis proximal, las proteínas solubles, rancidez oxidativa, y color mostraron que todas las muestras glaseadas con hidrocoloides mantienen sus características y protege al lomo de atún ante la pérdida de humedad y retrasa la degradación de las proteínas. De igual manera la carragenina mostró un mejor desempeño como empaque a concentraciones de 0,05% en comparación con la gelatina.

Numerous studies have been focused to natural ingredients to maintain the quality and shell life of foods. Edibles coating, biodegradable ingredients, such as hydrocolloids and proteins can be used for coating fish with the purpose to suppress changes of quality during frozen storage. At the present time several developing of edibles packing, like glaze using hydrocolloids, (gelatin, carrageen, starch), that besides acts as protective film for food, they are economic, can be ingested by the consumer without toxicity risk, help to preserve organoleptics and nutritional characteristics of the product and, being biodegradable they contribute to the conservation of the atmosphere. The objective of the present study was to evaluate the incorporation of hydrocolloids in the glazing tuna process as alternative of packing, to enhance its physical and chemical characteristics. Samples of tuna was glazed incorporating to its solutions of carrageen at 0.05, 0,1 and 0.15%, and gelatin at 0.5, 1%. The samples were shaped as square (15 cm3), frozen al -30ºC and glazed incorporating hydrocolloids submerging the sample its solutions at 0 ºC by 30 seconds and storage at -10ºC by 0, 15 and 30 days. Proximal analysis results, soluble proteins, TBA, and color showed that all the samples glazed with hydrocolloids decrease deterioration of the tuna products respect to samples glazed without hydrocolloids; concluding that glazing adding hydrocolloids protects tuna for loss humidity and delays degradation of proteins. Moreover, carrageen shows to a better performance at the concentrations of 0.05% compared with the gelatin and the starch.

[Tuna (Thunnus thynnus) glazed with hydrocolloids as alternative of edible coatings and storaged at -10 degrees C]. / El glaseado incorporando hidrocoloides como alternativa en el empaque de lomo de atún (Thunnus thynnus) congelado y almacenado a -10 degrees C.

Numerous studies have been focused to natural ingredients to maintain the quality and shell life of foods. Edibles coating, biodegradable ingredients, such as hydrocolloids and proteins can be used for coating fish with the purpose to suppress changes of quality during frozen storage. At the present time several developing of edibles packing, like glaze using hydrocolloids, (gelatin, carrageen, starch), that besides acts as protective film for food, they are economic, can be ingested by the consumer without toxicity risk, help to preserve organoleptics and nutritional characteristics of the product and, being biodegradable they contribute to the conservation of the atmosphere. The objective of the present study was to evaluate the incorporation ofhydrocolloids in the glazing tuna process as alternative of packing, to enhance its physical and chemical characteristics. Samples of tuna was glazed incorporating to its solutions of carrageen at 0.05, 0,1 and 0.15%, and gelatin at 0.5, 1%. The samples were shaped as square (15 cm3), frozen al -30 degrees C and glazed incorporating hydrocolloids submerging the sample its solutions at 0 degrees C by 30 seconds and storage at -10 degrees C by 0, 15 and 30 days. Proximal analysis results, soluble proteins, TBA, and color showed that all the samples glazed with hydrocolloids decrease deterioration of the tuna products respect to samples glazed without hydrocolloids; concluding that glazing adding hydrocolloids protects tuna for loss humidity and delays degradation of proteins. Moreover, carrageen shows to a better performance at the concentrations of 0.05% compared with the gelatin and the starch.

[Physical and chemical evaluation during refrigeration storage of salted catfish (Pseudoplatystoma sp.) in brine solution, and packed under vacuum]. / Evaluación fisica y química de filetes de bagre (Pseudoplatystoma sp.) salados en salmuera empacados al vacío y almacenados en refrigeración.

Salting fish in the south Venezuelan towns are still the main method of preserving fish including cutt, and salting fish process, storage and commercialization. As the result, salted-dried fish is particularly susceptible to spoilage by a number of factors, including lipid oxidation, browning meat. Packing salted fish product is an alternative increasing storage life time reducing lost of quality and enhancing the storage time. The present study evaluated the physic, chemist, and sensory quality of fish fillet from cat fish (Pseudoplatystoma sp.) from Apure state, Venezuela. Fillet fish were placed in brine solution at 36% of sodium chloride 1:2 fillet: brine solution; after, they were packed under followed conditions: vacuum, vacuum and storage under refrigeration condition, and room temperature. The results showed significant differences (p < 0.01) for moisture, salt content, and Aw. The fillets packed at vacuum and storage at 4 degrees C were significant different from the resting treatments; not significant differences were presented at room and refrigeration temperature after three moths. The best conditions treatment was vacuum packing and refrigeration at 4 degrees C.

Evaluación física y química de filetes de bagre (Pseudoplatystoma sp) salados en salmuera empacados al vacío y almacenados en refrigeración / Physical and chemical evaluation during refrigeration storage of salted catfish (Pseudoplatystoma sp) in brine solution, and packed under vacuum

El salado es un proceso artesanal que incluye la adición de sal al músculo de pescado (seco-salado) y almacenado hasta su venta. Uno de los factores que limita la calidad del pescado salado es la oxidación de los lípidos por el contacto con el oxigeno y en consecuencia el oscurecimiento de la carne, por lo que una alternativa para mejorar la calidad de dichos productos sería el salado en soluciones de salmuera saturada. El propósito del presente estudio fue evaluar la conservación de filetes de bagre en una solución de salmuera al 36 por ciento empacado al vacío, almacenados a temperatura ambiente (27°C), y de refrigeración como una alternativa para mantener la calidad y aumentar el tiempo de vida útil de estas especies de pescado con alta demanda al sur de Venezuela. Las muestras fueron obtenidas en San Fernando de Apure, Edo. Apure; fileteados y sometidos a un ensalmuerado con una solución de cloruro de sodio (NaCl) al 36 por ciento en una relación 1:2 pescado:salmuera durante nueve días. Los resultados mostraron diferencias significativas (P< 0,05) en los parámetros de humedad, concentración de sal, y AW. Los filetes que fueron empacados al vacío y almacenados a 4ºC resultaron significativamente diferentes (P< 0,05) al resto de los tratamientos ambiente y atmosfera sin modificar; no observándose diferencias significativas debido a la temperatura de almacenamiento a los 3 meses. La condición más favorable para conservar el pescado salado en salmuera con un empacado al vacío y refrigerado a 4ºC.

Salting fish in the south Venezuelan towns are still the main method of preserving fish including cutt, and salting fish process, storage and commercialization. As the result, salted-dried fish is particularly susceptible to spoilage by number factors, including lipid oxidation, browning meat. Packing salted fish product is an alternative increasing storage life time reducing lost of quality and enhancing the storage time. The present study evaluated the physic, chemist, and sensory quality of fish fillet from cat fish (Pseudoplatystoma sp.) from Apure state, Venezuela. Fillet fish were placed in brine solution at 36 percent of sodium chloride 1:2 fillet: brine solution; after, they were packed under followed conditions: vacuum, vacuum and storage under refrigeration condition, and room temperature. The results showed significant differences (p<0.01) for moisture, SALT content, and Aw. The fillets packed at 4 ºC were significant different from the resting treatments; not significant differences were presented at room and refrigeration temperature after three moths. The best conditions treatment was vacuum packing and refrigeration at 4ºC.

Influence of washing and frozen storage on the myofibrillar protein fraction in sardine mince flesh

El almacenamiento congelado de especies pesqueras, como la sardina, resulta en cambios significativos en sus propiedades funcionales las cuales determinan su tiempo de vida en almacenamiento. La pulpa de sardina se caracteriza por un alto contenido de grasa, músculo oscuro, y proteínas sarcoplasmáticas que inhiben la formación de geles a base de esta pulpa. Aplicando tratamiento de lavado a la pulpa de sardina se remueven compuestos indeseables para la preparación de productos a base de esta pulpa y a la vez aumentando su tiempo de vida en anaquel. El objetivo del presente estudio fue evaluar el efecto del almacenamiento en congelación a –30°C sobre la fracción de las proteínas miofibrilares de la pulpa de sardina tratada con soluciones al 0,5 por ciento de bicarbonato de sodio. Lotes de pulpa de sardina se le aplicó tratamiento de lavado con una solución de bicarbonato de sodio al 0,5 por ciento y luego centrifugadas a 300 rpm por 15 min. para la eliminación del agua remanente. Lotes de 100 gr. fueron empacados en bolsas de polipropileno y almacenadas a –30°C y analizadas cada 30 días durante150 días. Las proteínas nmiofibrilares fueron extraídas con buffer fosfato (tris HCl, KCl, EDTA, pH 7,6), y evaluadas por la técnica de electroforesis, SDS-PAGE. Las bandas de las diferentes proteínas y sus productos de degradación fueron analizadas y digitalizadas utilizando un Gel Doc 2000 y un programa Quality One 4.1.1 de Bio-Rad. Las principales bandas y sus productos de degradación fueron identificados por comparación de estos contra un estándar de peso molecular. A los 60 días se observó el comienzo del deterioro de las proteínas miofibrilares con pesos moleculares aparentes entre 220 y 65KD, y la formación de agregados moleculares de alto peso molecular. A los 120 días este deterioro se hace más pronunciado apareciendo gran cantidad de bandas de bajo peso molecular, péptidos, los cuales incrementan a medida que transcurre el tiempo de almacenamiento congelado...

Frozen storage of fish species, such as sardine, result in detrimental changes in functional properties that determine storage life. Sardine meat is characterized by high fat content, dark meat, and sarcoplasmic proteins that inhibit gel formation. Washing mince flesh with solutions such as sodium bicarbonate is very effective for removing undesirable components. The objective of this research was to study the effects of frozen storage at -30°C in the myofibrillar protein fraction of sardine mince flesh washed with 0.5% sodium bicarbonate solution. Samples of sardine-minced flesh were washed three times with a 0.5% of sodium bicarbonate solution and centrifuged at 3000 rpm for 15 minutes. These samples were divided in lots of 100 g. packed in plastic bags and stored at -30°C, and analyzed every 30 days for 150 days. The myofibrillar proteins were extracted using a phosphate buffer (tris HCl, KCl, EDTA, pH 7.6), and evaluated by SDS-PAGE. The bands were analyzed and digitalized with a Gel Doc 2000 and Quality One 4.1.1 by Bio-Rad. The main bands of myofibrillar protein were identified by comparison of these against a prestained molecular weight standard. After 60 days there was deterioration of the myofibrillar protein fraction with apparent molecular weight between 220 and 65KD, and the formation of molecular aggregates at high molecular weight occurred. After 120 days due to myofibrillar protein deterioration, protein and peptides with low molecular weight were formed and increasing throughout frozen storage. Understanding the mechanism involved in the deterioration of the mince flesh during frozen storage we would enable to help the establishment of quality parameters and ability to predict storage life for that product.