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.

Cytotoxicity and Quinone Reductase Activity Stimulating Effects of Fin of Thunnus Thynnus Extracts in Various Cancer Cells

In this study, we investigated the anticancer activity of the fin of Thunnus Thynnus (TT ). TT was extracted with methanol (TTM ), and then further fractionated into four subfractions by using solvent partition method, affording hexane (TTMH ), methanol (TTMM ), butanol (TTMB )and aquous (TTMA )soluble fractions. We determined the cyto-toxicity of these four fractions in four kind of cancer cell lines, such as HepG2, MCF-7, B16-F10 and HT29 by MTT assay. The TTMM showed the strongest cytotoxic effect at the concentration of 150 microgram/mL, displaying 95% on the HepG2 cell lines and 82% on MCF-7 cell line. The morphological changes such as membrane shirinking and blebbing of cells were also observed by TTMM treatment in HT29 cell. In addition, we observed that quinone reductase (QR ) activity was elevated by only TTMM and TTMH treatments in HepG2 cell. QR activity was increased to around 2.0 and 1.8 times in TTMM and TTMH treated HepG2 cell at 100 microgram/mL, respectively, compared to that in control. Although further studies are needed, the present work could suggest that the fin of TT has a potential to be usable as a chemo-preventive agent against cancer.