Abstract Fishing products are characterized for being highly perishable; therefore, preservation methods are used to retain freshness, quality and extend shelf life. One of the factors that influences most on the loss of freshness, quality and shelf life, is storage temperature. This study evaluated the effect of storage temperature (0 °C and 5 °C) on the quality and shelf life of tilapia (Oreochromis niloticus) muscle during 20 days of storage. Adenosine 5’-triphosphate (ATP) and related compounds, K-value, pH, color, texture, water holding capacity (WHC), total volatile bases (TVB-N), and total count of mesophilic microorganisms were monitored. The results indicated that time and storage temperature had a significant effect (P < 0.05) on K-value, TVB-N, and total count of mesophilic microorganisms. The present study concludes that, by storing tilapia muscle at a lower temperature, a longer shelf life is produced, which implies that the product can be kept with good quality for a longer period of time. Likewise, the edible quality of tilapia muscle was affected by storage temperature, observing a shelf life of 16 days at 0 °C and 8 days at 5 °C.

Resumen Los productos pesqueros se caracterizan por ser altamente perecederos; por lo tanto, se utilizan métodos para conservar la frescura, la calidad y extender la vida útil. Uno de los factores que más influye en la pérdida de frescura, calidad y vida útil es la temperatura de almacenamiento. Este estudio evaluó el efecto de la temperatura de almacenamiento (0 °C y 5 °C) sobre la calidad y vida útil del músculo de tilapia (Ore ochromis niloticus) durante 20 días de almacenamiento. Se monitorearon el ATP (adenosina-5’-trifosfato) y compuestos relacionados, el indice K, el pH, el color, la textura, la capacidad de retención de agua (CRA), las bases volátiles totales (TVB-N) y el recuento total de microorganismos mesófilos. Los resultados indicaron que el tiempo y la temperatura de almacenamiento tuvieron un efecto significativo (P < 0.05) sobre el indice K, TVB-N y el recuento total de microorganismos mesófilos. En el presente estudio se concluye que al almacenar el músculo de tilapia a menor temperatura se produce una mayor vida útil, lo que implica que el producto se puede conservar con buena calidad por más tiempo. Asimismo, la calidad comestible del músculo de tilapia se vio afectada por la temperatura de almacenamiento, observándose una vida útil de 16 días a 0 °C y 8 días a 5 °C.

Abstract The aim of this research was to evaluate the effect of storage temperature (0 and 5°C) on the main metabolites and related parameters to rigor mortis in muscle of tilapia (Oreochromis niloticus). The rigor index (IR), adenosine 5’-triphosphate (ATP), glycogen, lactic acid, pH and texture were evaluated. The IR analysis was performed during 266 hours of storage at the two temperatures, while the rest of the parameters were monitored at 0 and at 48 hours of storage at both temperatures. It was found that both temperature and storage time, had a significant effect on IR, being more pronounced at 5°C compared to 0°C.

Resumen El objetivo de la presente investigación fue evaluar el efecto de la temperatura de almacenamiento (0 y 5ºC) sobre los principales metabolitos y parámetros relacionados con el rigor mortis del músculo de tilapia (Oreochromis niloticus). Se evaluó el índice de rigor (IR), adenosina 5´-trifosfato (ATP), glucógeno, ácido láctico, pH y textura. El análisis del IR se realizó durante 266 h de almacenamiento a las dos temperaturas, mientras que el resto de los parámetros se monitorearon al tiempo 0 y a las 48 h de almacenamiento en ambas temperaturas. Se encontró que tanto la temperatura como el tiempo de almacenamiento presentaron un efecto significativo sobre el IR, siendo más pronunciado a 5°C en comparación al de 0°C.

Avaliou-se o efeito do transporte em refrigeração por 48 horas e quatro dias de armazenamento sobre a qualidade e vida de prateleira da gônada do bivalve pata de leão, Nodipecten subnodosus. Determinou-se a composição centesimal, a adenosina 5'trifosfato (ATP) e afins, o índice K, bases voláteis totais (TVB-N), trimetilamina (TMA-N), pH, perfil de ácidos graxos e análise microbiológica. A Gônada apresentou uma importante composição de ácidos graxos essenciais e baixos níveis iniciais de ATP, enquanto o índice K manteve-se constante. Quanto a TVB -N e TMA- N, apenas as primeiras ultrapassaram os limites admissíveis. Os valores de pH não mostraram nenhuma mudança significativa durante o armazenamento e, apesar dos altos níveis de TVB -N, de acordo com a análise quantitativa e microbiológica TMA- N, a segurança do produto foi demonstrada após quatro dias sob as condições de transporte e armazenamento utilizado.

The effect of refrigerated 48h transport and 4 days storage on the quality and shelf life of the whole lion's paw scallop Nodipecten subnodosus gonad was evaluated. Proximal composition, adenosine 5´triphosphate (ATP) and related products, K-value, total volatile bases (TVB-N), trimethylamine (TMA-N), pH, fatty acid profile and microbiological analyses were quantified. Gonad holds a significant composition of essential fatty acids while levels of gonadal ATP were initially low; moreover, K-value of the gonad remained constant. With respect to TVB-N and TMA-N, only the former exceeded allowed limits. The pH level showed no significant variation during storage and, despite the high level of TVB-N, according to the TMA-N as well as microbiological analyses it was demonstrated innocuity after 4 days under the transportation and storage conditions utilized.