RESUMO
Trypsins (E.C. 3.4.21.4) are digestive enzymes that catalyze the hydrolysis of peptide bonds containing arginine and lysine residues. Some trypsins from fish species are active at temperatures just above freezing, and for that are called cold-adapted enzymes, having many biotechnological applications. In this work, we characterized a recombinant trypsin-III from Monterey sardine (Sardinops caeruleus) and studied the role of a single residue on its cold-adapted features. The A236N mutant from sardine trypsin-III showed higher activation energy for the enzyme-catalyzed reaction, it was more active at higher temperatures, and exhibited a higher thermal stability than the wild-type enzyme, suggesting a key role of this residue. The thermodynamic activation parameters revealed an increase in the activation enthalpy for the A236N mutant, suggesting the existence of more intramolecular contacts during the activation step. Molecular models for both enzymes suggest that a hydrogen-bond involving N236 may contact the C-terminal α-helix to the vicinity of the active site, thus affecting the biochemical and thermodynamic properties of the enzyme.
Assuntos
Peixes/metabolismo , Mutação , Tripsina/química , Tripsina/genética , Animais , Temperatura Baixa , Ativação Enzimática , Estabilidade Enzimática , Proteínas de Peixes/química , Proteínas de Peixes/genética , Peixes/genética , Ligação de Hidrogênio , Modelos Moleculares , Simulação de Acoplamento Molecular , Estrutura Secundária de ProteínaRESUMO
MicroRNAs are endogenous highly conserved short (~ 21 nucleotides) non-coding RNA molecules that play key roles in post-transcriptional gene regulation by translational inhibition or by target mRNA cleavage. In this report, using high stringent computational-based methods, a total of 101 putative miRNAs were identified from European sardine fish (Sardina pilchardus Walbaum, 1792). All the precursors of identified sardine miRNAs formed stable stem-loop structures and displayed high minimum free energy index (MFEI) values. For the experimental validation of the computationally predicted miRNAs, a tissue-specific quantitative study of eight randomly selected putative sardine miRNAs (spi-miR9, spi-miR26, spi-miR128, spi-miR129, spi-miR132, spi-miR212, spi-miR219, and spi-miR338) was performed in brain and liver and all the selected miRNAs were found to be overexpressed in brain tissue. Moreover, using RNAhybrid, a total of 83 potential target proteins of the characterized sardine miRNAs were identified those are involved in transcription, cellular development, defense mechanism, and various signaling pathways. To the best of our knowledge, this is the first report of sardine microRNAs and their targets.
RESUMO
Brazilian sardine is emerging as a promising species in Aquaculture. This study describes for the first time a case of parasitic infestation by Amyloodinium in Brazilian sardines Sardinella brasiliensis obtained from natural spawning in captivity. The sardines kept in nurseries were naturally parasitized by the amylodiniosis causative agente the dynoflagellate A. ocellatum with high mortalities above 50%. Fish presented clinical signs characteristic of amyloodiniosis which included easily perceived behavioral changes such as loss of appetite, scraping of the body against objects, walls and bottom, nursery pipes, agglomerations near the aerators and water inlets, presented with accelerated opercular beating and erratic swimming. For therapeutic treatment copper sulfate was used for 10 days. At the end of the treatment period the fish had no clinical signs or presence of the parasite on the body surface, indicating that the application of copper sulfate in concentration of 0.2 mg L-1 of Cu+ was effective to control this parasite, apparently without causing damage to Brazilian sardine.
Assuntos
Antiprotozoários/uso terapêutico , Sulfato de Cobre/uso terapêutico , Dinoflagellida/efeitos dos fármacos , Doenças dos Peixes/prevenção & controle , Peixes , Infecções Protozoárias em Animais/prevenção & controle , Animais , Aquicultura , Brasil , Doenças dos Peixes/parasitologia , Infecções Protozoárias em Animais/parasitologiaRESUMO
BACKGROUND: Trypsin from fish species is considered as a cold-adapted enzyme that may find potential biotechnological applications. In this work, the recombinant expression, refolding and activation of Trypsin I (TryI) from Monterey sardine (Sardinops sagax caerulea) are reported. METHODS: TryI was overexpressed in Escherichia coli BL21 as a fusion protein of trypsinogen with thioredoxin. Refolding of trypsinogen I was achieved by dialysis of bacterial inclusion bodies with a recovery of 16.32 mg per liter of Luria broth medium. RESULTS: Before activation, the trypsinogen fusion protein did not show trypsin activity. Trypsinogen I was activated by adding 0.002 U of native TryI purified from the sardine pyloric caeca (nonrecombinant). The activated recombinant trypsin showed three times more activity than the nonrecombinant trypsin alone. CONCLUSION: The described protocol allowed obtaining sufficient amounts of recombinant TryI from Monterey sardine fish for further biochemical and biophysical characterization of its coldadaptation parameters.
Assuntos
Escherichia coli , Proteínas de Peixes , Peixes/genética , Corpos de Inclusão , Redobramento de Proteína , Tripsina , Animais , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Peixes/biossíntese , Proteínas de Peixes/química , Proteínas de Peixes/genética , Proteínas de Peixes/isolamento & purificação , Corpos de Inclusão/química , Corpos de Inclusão/genética , Corpos de Inclusão/metabolismo , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Tripsina/biossíntese , Tripsina/química , Tripsina/genética , Tripsina/isolamento & purificaçãoRESUMO
INTRODUCCIÓN: La mayor parte de la población rural en México adquiere casi la mitad de su energía de la tortilla de maíz y sus fuentes de proteína son principalmente de origen vegetal. OBJETIVO: Obtener un concentrado de proteína de sardina para adicionar harina de maíz e identificar la concentración que proporcione la mejor calidad biológica de las tortillas sin modificar sus características físicas y sensoriales. MÉTODO: Obtención de un concentrado de proteína de sardina y elaboración de tortillas con harina de maíz suplementada con diferentes concentraciones de proteína. Las características físicas y sensoriales de las tortillas fueron evaluadas por panelistas no entrenados. La calidad biológica de las tortillas se analizó en un modelo murino (crecimiento y la relación de eficiencia de proteína, PER). Para el análisis se utilizó estadística paramétrica. RESULTADOS: Se obtuvo un concentrado de proteína con 70.48 g/100 g. La suavidad, inflado, doblado y calidad de las tortillas preparadas con las mezclas con 0.63-3.75 % de proteínas de sardina fueron comparables con los de las tortillas elaboradas con harina no adicionada. El crecimiento de las ratas alimentadas con tortillas adicionadas fue mayor que el de las alimentadas con harina no adicionada; la diferencia fue significativa a partir de la concentración de 3.75 % (p < 0.05). El PER de las tortillas con 3.75 % de proteínas de sardina fue de 2.41, comparable al de la proteína de referencia (caseína). CONCLUSIÓN: La harina de maíz adicionada con proteínas de sardina en una proporción de 96.25:3.75 % mejora el valor biológico de las tortillas sin alterar sus características físicas y sensoriales. INTRODUCTION: Most part of the rural population in Mexico obtains almost half its energy from corn tortilla, and its sources of protein are mainly of vegetal origin. OBJECTIVE: To obtain a concentrate of sardine protein (SP) to supplement corn flour, and to identify which concentration provides corn tortillas with a better biological value, without modifying its physical and sensorial characteristics. METHOD: Obtainment of the SP concentrate, preparation of tortillas with corn flour and different SP concentrations, assessment of tortillas physical and sensorial characteristics by untrained panelists, assessment of biological quality in a murine model (growth and protein efficiency ratio [PER]). Parametric statistics was used. RESULTS: A protein concentrate of 70.48 g/100 g was obtained. Smoothness, blistering, foldability and quality of the tortillas prepared with mixtures containing 0.63-3.75% of SP were comparable to those of tortillas prepared with non-supplemented flour. The growth of rats fed supplemented tortillas was superior; the difference was significant with ≥ 3.75% concentrations (p < 0.05). The PER of tortillas with 3.75% of SP was 2.41, which was comparable to that of the reference protein (casein). CONCLUSION: SP-supplemented corn flour at a 96.25:3.75% ratio improves the biological value of tortillas without modifying their physical and sensorial characteristics.
Assuntos
Proteínas de Peixes , Alimentos Fortificados , Valor Nutritivo , Zea mays , Animais , Peixes , Alimentos Fortificados/análiseRESUMO
The Brazilian sardine (Sardinella brasiliensis) is the main fishery resource in Brazil which holds directly the canning industry, as raw material, and indirectly the tuna fishing because juveniles are used as live bait. The UFSC through Live-Bait Project is developing production techniques of Brazilian sardine in captive aimed at the sustainable use of the resource, however there is no information about the toxicity of nitrogenous compounds in the culture of this species. This study was conducted to estimate the acute toxicity of ammonia (NH3-N) on the juvenile Brazilian sardine. Groups of five fish (1.04 ± 0.20 g) were exposed to five concentrations of NH3-N (0.60 to 1.47 mg L-1) for 96 h plus control group in three replicates. Tests were run using a standard semi-static system with 100% daily renewal of water and toxicants. The results were based on mortality data registered for the different concentrations tested, using the software Trimmed Spearman Karber method. The median lethal concentration (LC50) after 96 h of exposure to NH3-N was estimated at 0.74 (0.61-0.90) mg L-1. The results indicates that the juvenile Brazilian sardine is relatively sensitive to ammonia compared to other marine fish and particular attention must be given to this compound in culture systems.(AU)
A sardinha-verdadeira (Sardinella brasiliensis) é o principal recurso pesqueiro do Brasil que sustenta diretamente a indústria de enlatados, como matéria prima, e indiretamente a pesca dos tunídeos, pois juvenis são utilizados como isca-viva. A UFSC através do Projeto Isca-Viva vem desenvolvendo técnicas de produção de sardinha-verdadeira em cativeiro com vistas ao uso sustentável do recurso, entretanto não existem informações sobre a toxicidade dos compostos nitrogenados no cultivo desta espécie. O objetivo deste estudo foi de estimar a toxicidade aguda de amônia (NH3-N) em juvenis de sardinha-verdadeira. Grupo de cinco peixes (1,04 ± 0,20 g) foram expostos a cinco concentrações de NH3-N (0,60 a 1,47 mg L-1) durante 96 h mais um grupo controle em triplicata. Os testes foram conduzidos em um sistema semi-estático com renovação diária total dos meios experimentais. Os resultados foram apresentados como dados de mortalidade, registrados nas diferentes concentrações testadas, utilizando o software Trimmed Spearman Karber Method. A concentração letal (LC50) após 96 h de exposição a NH3-N foi estimada em 0,74 (0,61-0,90) mg L-1. Os resultados indicam que juvenis de sardinha-verdadeira são relativamente sensíveis à amônia em relação a outros peixes marinhos e atenção especial deve ser dada a este composto em sistemas de cultivo.(AU)
Assuntos
Animais , Amônia/toxicidade , Peixes/metabolismo , Toxicidade , Mortalidade , Fauna MarinhaRESUMO
The Brazilian sardine (Sardinella brasiliensis) is the main fishery resource in Brazil which holds directly the canning industry, as raw material, and indirectly the tuna fishing because juveniles are used as live bait. The UFSC through Live-Bait Project is developing production techniques of Brazilian sardine in captive aimed at the sustainable use of the resource, however there is no information about the toxicity of nitrogenous compounds in the culture of this species. This study was conducted to estimate the acute toxicity of ammonia (NH3-N) on the juvenile Brazilian sardine. Groups of five fish (1.04 ± 0.20 g) were exposed to five concentrations of NH3-N (0.60 to 1.47 mg L-1) for 96 h plus control group in three replicates. Tests were run using a standard semi-static system with 100% daily renewal of water and toxicants. The results were based on mortality data registered for the different concentrations tested, using the software Trimmed Spearman Karber method. The median lethal concentration (LC50) after 96 h of exposure to NH3-N was estimated at 0.74 (0.61-0.90) mg L-1. The results indicates that the juvenile Brazilian sardine is relatively sensitive to ammonia compared to other marine fish and particular attention must be given to this compound in culture systems.
A sardinha-verdadeira (Sardinella brasiliensis) é o principal recurso pesqueiro do Brasil que sustenta diretamente a indústria de enlatados, como matéria prima, e indiretamente a pesca dos tunídeos, pois juvenis são utilizados como isca-viva. A UFSC através do Projeto Isca-Viva vem desenvolvendo técnicas de produção de sardinha-verdadeira em cativeiro com vistas ao uso sustentável do recurso, entretanto não existem informações sobre a toxicidade dos compostos nitrogenados no cultivo desta espécie. O objetivo deste estudo foi de estimar a toxicidade aguda de amônia (NH3-N) em juvenis de sardinha-verdadeira. Grupo de cinco peixes (1,04 ± 0,20 g) foram expostos a cinco concentrações de NH3-N (0,60 a 1,47 mg L-1) durante 96 h mais um grupo controle em triplicata. Os testes foram conduzidos em um sistema semi-estático com renovação diária total dos meios experimentais. Os resultados foram apresentados como dados de mortalidade, registrados nas diferentes concentrações testadas, utilizando o software Trimmed Spearman Karber Method. A concentração letal (LC50) após 96 h de exposição a NH3-N foi estimada em 0,74 (0,61-0,90) mg L-1. Os resultados indicam que juvenis de sardinha-verdadeira são relativamente sensíveis à amônia em relação a outros peixes marinhos e atenção especial deve ser dada a este composto em sistemas de cultivo.
Assuntos
Animais , Amônia/toxicidade , Mortalidade , Peixes/metabolismo , Toxicidade , Fauna MarinhaRESUMO
Although modern beaked whales (Ziphiidae) are known to be highly specialized toothed whales that predominantly feed at great depths upon benthic and benthopelagic prey, only limited palaeontological data document this major ecological shift. We report on a ziphiid-fish assemblage from the Late Miocene of Peru that we interpret as the first direct evidence of a predator-prey relationship between a ziphiid and epipelagic fish. Preserved in a dolomite concretion, a skeleton of the stem ziphiid Messapicetus gregarius was discovered together with numerous skeletons of a clupeiform fish closely related to the epipelagic extant Pacific sardine (Sardinops sagax). Based on the position of fish individuals along the head and chest regions of the ziphiid, the lack of digestion marks on fish remains and the homogeneous size of individuals, we propose that this assemblage results from the death of the whale (possibly via toxin poisoning) shortly after the capture of prey from a single school. Together with morphological data and the frequent discovery of fossil crown ziphiids in deep-sea deposits, this exceptional record supports the hypothesis that only more derived ziphiids were regular deep divers and that the extinction of epipelagic forms may coincide with the radiation of true dolphins.
Assuntos
Mergulho , Fósseis , Baleias/anatomia & histologia , Animais , Evolução Biológica , Peixes/anatomia & histologia , Comportamento Predatório/fisiologia , Baleias/fisiologiaRESUMO
[...] O objetivo deste estudo foi avaliar o efeito do consumo de óleos ricos em ácidos graxos poli-insaturados ômega-6 (PUFAs n-6) e ômega-3 (PUFAs n-3) sobre o desempenho e a resposta imunológica de frangos de corte frente a um desafio antigênico. Foram comparadas dietas formuladas com 7% de óleo de soja (OS), linhaça (OL) ou sardinha (OP), fornecidas a 240 frangos da linhagem Cobb, divididos em 24 grupos de 10 aves cada, num arranjo experimental 3x2 (3 tipos de óleo e aves vacinadas ou não vacinadas) e 4 repetições. O óleo de soja é rico em ácido linoleico, um PUFA n-6, o óleo de linhaça é fonte de ácido alfa-linolênico, um PUFA n-3, e o óleo de sardinha, de outros PUFAs n-3, como os ácidos eicosapentaenoico e docosahexaenoico. O consumo de ração, o ganho de peso e a conversão alimentar foram avaliados aos 21, 35 e 42 dias. Aos 7 e aos 21 dias de idade, metade das aves recebeu vacina contra doença de Newcastle. Quinze dias após a imunização, avaliou-se a produção de anticorpos pelo método de ELISA, expressa pela densidade óptica a 450 nm (D.O. 450nm). Apenas as aves alimentadas com ração contendo OS apresentaram maior imunidade humoral (P<0,05) após a vacinação. A resposta linfoproliferativa das aves, que expressa a imunidade celular, foi maior entre as aves vacinadas, em comparação às aves não vacinadas (P<0,05), independentemente do óleo utilizado. A fonte de óleo da ração ou a vacinação não influenciaram o ganho de peso das aves (P>0,05). Entre as aves que receberam dieta com OS, as aves vacinadas apresentaram pior conversão alimentar (P<0,05). Nos grupos que consumiram ração com OL ou OP, a vacinação não influenciou a conversão alimentar (P>0,05), considerando todo o período experimental. A utilização de óleo rico em PUFA n-6 na dieta de frangos de corte aumentou a resposta humoral, mas não influenciou a resposta celular frente a um desafio antigênico.(AU)
[...] The objective of this study was to evaluate the effect of the consumption of oils rich in omega-6 (n-6 PUFA) and omega-3 (n-3 PUFA) polyunsaturated fatty acids on the performance and the immune response of broilers submitted to an antigenic challenge. Diets were formulated with either 7% soybean oil (SO), linseed oil (LO) or sardine oil (PO) and provided to 240 Cobb broilers which were divided into 24 groups of 10 birds each, following a 3x2 experimental arrangement (3 types of oil and vaccinated or non-vaccinated birds) and four replications. Soybean oil is rich in linoleic acid (n-6 PUFA), linseed oil a source of alfa-linolenic acid (n-3 PUFA) and the sardine oil is a source of eicosapentaenoic and docosahexaenoic acids (other n-3 PUFA). Feed intake, weight gain and feed conversion were evaluated at 21, 35 and 42 days. Half of the birds were vaccinated against Newcastle disease at 7 and 21 days. Fifteen days after the immunization, the production of antibodies was evaluated by ELISA and expressed by optical density at 450 nm (O.D. 450 nm). Only the birds fed ration containing SO presented higher humoral immune response (p<0.05) after vaccination. The lymphoproliferative response, which expresses the cellular immunity, was higher in vaccinated than in the unvaccinated birds (P<0.05), regardless of the oil used. Neither the oil source in the ration nor the vaccination influenced birds' weight gain (P>0.05). The vaccination impaired the feed conversion of the birds fed diet containing SO (P<0.05) but did not influence feed conversion of the birds fed rations with LO or PO (P>0.05). The use of oil rich in n-6 PUFA in broilers' diet increased humoral response, but did not influence the cellular response against an antigenic challenge.(AU)
Assuntos
Animais , Galinhas/crescimento & desenvolvimento , Galinhas/imunologia , Ácidos Graxos Ômega-3/administração & dosagem , Ácidos Graxos Ômega-6/administração & dosagem , Imunidade Celular , Ácidos Graxos Insaturados/administração & dosagem , Vacinas , Doença de Newcastle/dietoterapiaRESUMO
A composição de ácidos graxos da dieta pode influenciar o desempenho produtivo e o sistema imune de frangos de corte. O objetivo deste estudo foi avaliar o efeito do consumo de óleos ricos em ácidos graxos poli-insaturados ômega-6 (PUFAs n-6) e ômega-3 (PUFAs n-3) sobre o desempenho e a resposta imunológica de frangos de corte frente a um desafio antigênico. Foram comparadas dietas formuladas com 7% de óleo de soja (OS), linhaça (OL) ou sardinha (OP), fornecidas a 240 frangos da linhagem Cobb, divididos em 24 grupos de 10 aves cada, num arranjo experimental 3x2 (3 tipos de óleo e aves vacinadas ou não vacinadas) e 4 repetições. O óleo de soja é rico em ácido linoleico, um PUFA n-6, o óleo de linhaça é fonte de ácido alfa-linolênico, um PUFA n-3, e o óleo de sardinha, de outros PUFAs n-3, como os ácidos eicosapentaenoico e docosahexaenoico. O consumo de ração, o ganho de peso e a conversão alimentar foram avaliados aos 21, 35 e 42 dias. Aos 7 e aos 21 dias de idade, metade das aves recebeu vacina contra doença de Newcastle. Quinze dias após a imunização, avaliou-se a produção de anticorpos pelo método de ELISA, expressa pela densidade óptica a 450 nm (D.O. 450nm). Apenas as aves alimentadas com ração contendo OS apresentaram maior imunidade humoral (P<0,05) após a vacinação. A resposta linfoproliferativa das aves, que expressa a imunidade celular, foi maior entre as aves vacinadas, em comparação às aves não vacinadas (P<0,05), independentemente do óleo utilizado. A fonte de óleo da ração ou a vacinação não influenciaram o ganho de peso das aves (P>0,05). Entre as aves que receberam dieta com OS, as aves vacinadas apresentaram pior conversão alimentar (P<0,05)...
The fatty acid composition in the diet can affect the productive performance and the immune system of broiler chickens. The objective of this study was to evaluate the effect of the consumption of oils rich in omega-6 (n-6 PUFA) and omega-3 (n-3 PUFA) polyunsaturated fatty acids on the performance and the immune response of broilers submitted to an antigenic challenge. Diets were formulated with either 7% soybean oil (SO), linseed oil (LO) or sardine oil (PO) and provided to 240 Cobb broilers which were divided into 24 groups of 10 birds each, following a 3x2 experimental arrangement (3 types of oil and vaccinated or non-vaccinated birds) and four replications. Soybean oil is rich in linoleic acid (n-6 PUFA), linseed oil a source of alfa-linolenic acid (n-3 PUFA) and the sardine oil is a source of eicosapentaenoic and docosahexaenoic acids (other n-3 PUFA). Feed intake, weight gain and feed conversion were evaluated at 21, 35 and 42 days. Half of the birds were vaccinated against Newcastle disease at 7 and 21 days. Fifteen days after the immunization, the production of antibodies was evaluated by ELISA and expressed by optical density at 450 nm (O.D. 450 nm). Only the birds fed ration containing SO presented higher humoral immune response (p<0.05) after vaccination. The lymphoproliferative response, which expresses the cellular immunity, was higher in vaccinated than in the unvaccinated birds (P<0.05), regardless of the oil used. Neither the oil source in the ration nor the vaccination influenced birds' weight gain (P>0.05). The vaccination impaired the feed conversion of the birds fed diet containing SO (P<0.05) but did not influence feed conversion of the birds fed rations with LO or PO (P>0.05). The use of oil rich in n-6 PUFA in broilers' diet increased humoral response, but did not influence the cellular response against an antigenic challenge.
Assuntos
Animais , /administração & dosagem , /administração & dosagem , Galinhas/crescimento & desenvolvimento , Galinhas/imunologia , Imunidade Celular , Imunidade Humoral , Ácidos Graxos Insaturados/administração & dosagem , Doença de Newcastle/dietoterapia , VacinasRESUMO
The absence of the larval Anisakis simplex s. l. in samples from central Chile but heavy infections in fish from southern localities suggest the existence of two stocks of Strangomera bentincki, one closely associated with the central coast of Chile (landing port San Antonio and Talcahuano, c. 33° 30' S-36° 40' S) and the other associated with southern Chile (landing port Puerto Montt, c. 41° 30' S). Results confirm the usefulness of metazoan parasites, like A. simplex s. l. as biological markers.
Assuntos
Anisakis/isolamento & purificação , Peixes/classificação , Animais , Biomarcadores , Chile , Classificação/métodos , Peixes/parasitologiaRESUMO
El objetivo del presente estudio fue la evaluación de los parámetros físicos y químicos en sardinas (Sardinella aurita) recién capturadas, durante los meses de mayo, junio y julio. Los parámetros evaluados fueron: análisis proximal (humedad, proteína, grasa y ceniza), hierro, calcio, fósforo, cloruros, mercurio, cadmio, plomo, pH, ácido láctico (AL), bases volátiles totales (BVT), trimetilamina (TMA), solubilidad de proteínas en soluciones salinas (SPs), líquido exprimible (LE), color (L, a y b), degradación de nucleótidos, valor K%, Hx/Ino, aminas biógenas y perfil de ácidos grasos. Los resultados más relevantes son los siguientes: el análisis proximal mostró diferencias significativas entre los meses evaluados (P<0,05). Los valores de pH (5,94 a 5,96), ácido láctico (17,82 a 24,28 µmol/g), color: a (6,19 a 6,61) y L (40,54 a 46,10), reflejan una buena condición del tejido muscular y apariencia visual. Los valores de SPs (74,3 a 78,7%) y LE (15,0 a 18,5%) son indicativos de una excelente integridad de la proteína. Los parámetros de pH, ácido láctico, SPs y LE no mostraron diferencias significativas (P>0,05) entre los meses. El valor K obtenido (12,05 a 24,12) y el bajo contenido de aminas biógenas son indicativos también de una materia prima con alto grado de frescura. El perfil de ácidos grasos mostró una alta proporción de ácidos poliinsaturados (31,58 a 37,00%), especialmente de los ácidos eicosapentaenoico (14,19 a 16,06%) y docosahexaenoico (12,00 a 15,80%), lo cual puede ser beneficioso para consumo humano y para la prevención de algunas enfermedades. Todos los valores determinados (físicos y químicos) pueden ser considerados como representativos y típicos para esta especie de sardina (Sardinella aurita) recién capturada, unido a una correcta manipulación y almacenamiento en hielo.
The aim of this study was to evaluate the physical and chemical parameters of sardines (Sardinella aurita) recently captured during the months of May, June and July. The parameters evaluated were: proximate analysis (moisture, protein, fat and ash), iron, calcium, phosphorus, chlorine, mercury, cadmium, lead, pH, lactic acid (LA), total volatile bases (TBV), thrimethylamine (TMA), proteins solubility in saline solutions (SPs), water-binding capacity (WBC), color (L, a and b), nucleotide degradation, %K-value, Hx/Ino, biogenic amines, and fatty acids profile. The main results were: proximate analysis showed significant differences between the evaluated months (P<0.05). The pH values (5.94 to 5.96), lactic acid (17.92 to 24.28 µmol/g), color: a (6.19 to 6.61) and L (40.54 to 46.10), reflect good muscle condition and visual appearance. The SPs (74.3 to 78.7%) and LE (15.0 to 18.5%) were indicative of excellent protein integrity. The pH, lactic acid, PSs and LE not showed significant differences (P>0.05) between months. The K-value (12.05 to 24.12) and the low levels of biogenic amine were also indicative of a high freshness raw material. The fatty acid profile showed a high proportion of polyunsaturated fatty acids (31.58 to 37.00%), especially eicosapentaenoic acid (14.19 to 16.06%) and docosahexaenoic acid (12.00 to 15.80%) which can be beneficial for human consumption and for the prevention of some risk illness. All these present values (physical and chemical) could be considered as representative and typical for this specie of sardine (Sardinella aurita) in fresh condition, together with proper handling and ice storage.
RESUMO
Conocer la cinética de deshidratación osmótica de un alimento y los factores que la afectan son aspectos importantes para diseñar un adecuado proceso. En este trabajo se investigó la aplicación del modelo de Weibull normalizado para describir la deshidratación osmótica de láminas finitas de sardina y determinar el coeficiente de difusión efectivo del agua. La deshidratación osmótica se realizó durante 4 horas utilizando salmueras de diferentes concentraciones (0,15-0,27 g NaCl/g) y temperaturas (30-38°C). Durante el proceso se midió el contenido de agua en las láminas y estos valores se ajustaron al modelo de Weibull normalizado. Los altos valores del coeficiente de regresión (R² > 0,99), la alta significancia (α < 0,001) para el coeficiente de difusión (D) y el parámetro β, y los bajos valores del ji-cuadrado reducido, indicaron la aceptabilidad del modelo para describir el proceso y determinar el coeficiente de difusión efectivo De del agua. Los valores de D variaron entre 1,01 x 10-11 m²/s y 4, 30 x 10-11 m²/s.
Knowledge of kinetics of osmotic dehydration of a food and factors that cause effects are aspects import for the appropriate design of process. In this work the application of normalized Weibull model was investigated for describing the osmotic dehydration (OD) of sardine finite sheets and determining the effective diffusion coefficient for water. The OD was carried out during 4 hours using brine at different concentrations (0.15-0.27 g NaCl/g) and temperatures (30-38°C). During process the water content of shhets was measured and these values were fitted to normalized Weibull model. The high values of regression coefficients (R² > 0.99), high significance (α < 0.001) of diffusion coefficient (D), parameter β, and low values of chi-square indicated the acceptability of Weibull model for describing the process and determining the effective diffusion coefficient De for water. The values of D ranged from 1.01 x 10-11 m²/s to 4.30 x 10-11 m²/s.
RESUMO
O peixe é uma fonte de proteína de alto valor biológico tão importante quanto à carne. Devido aos mais diferentes métodos de conservação de alimentos, uma nova preocupação vem surgindo: a influência dos processos tecnológicos no perfil nutricional dos alimentos. O objetivo do presente trabalho foi avaliar o uso de atmosfera modificada em sardinha sobre a preservação das características nutricionais comparando o uso de atmosfera modificada com o processo de congelamento, técnica que usualmente é utilizada. Foi realizada a composição centesimal, a determinação dos teores totais e de diferentes extratos de cobre e zinco em sardinha fresca e conservada por 15 dias por congelamento e em embalagem de atmosfera modificada. Os dados foram tratados estatisticamente através do teste de Grubbs e t de Student. Verificou-se que, em relação aos macronutrientes, nenhum dos processos provocou modificações significativas.(...) Sendo assim, considerando aspectos do frescor da sardinha e por não alterar a fração do cobre, indica-se o uso da atmosfera modificada em relação ao congelamento.(AU)
The fish is a source of protein of high so important biological value as regards the meat. Due to the most different methods of food conservation, a new concern comes appearing: the influence of the technological processes in the nutritional profile of foods. The objective of the present work was to evaluate the atmosphere use modified in sardine on the preservation of the nutritions characteristics being compared the atmosphere use modified with the freezing process, technique that usually is used. The centesimal composition, the determination of total amounts and different extracts of copper and zinc in sardine cool and conserved per 15 days for freezing and in modified atmosphere packing was carried through. Both the Grubbs and Student's test were used for the analysis. It was verified and none of the macronutrients wad modified by technology process. Regarding the copper and rinc, the freezing process decreased the total content of copper and made chemical modifications of its fractions, while the modified atmosphere process did not provoke significant alterations. For zinc it does not have significant modifications in the total text or the fractions extracted with the use of the two methods of conservation. Being thus, considering aspects of the "coolness" of the sardine and for not modifying the fraction of copper, the use of of the atmosphere modified in relation to the freezing is indicated. (AU)
Assuntos
Peixes , Composição de Alimentos , Conservação de Alimentos , Temperatura , Embalagem de Alimentos , Alimentos CongeladosRESUMO
Las buenas prácticas de fabricación (BPF) y los procedimientos operativos estándares de saneamiento (POES) en planta son considerados los pre-requisitos esenciales para la implementación del sistema de análisis de peligros y puntos de control crítico (HACCP) como una herramienta para la inocuidad de alimentos durante su procesamiento. El objetivo de esta investigación fue la evaluación de las BPF/POES en una línea de sardina (Sardinella aurita) entera congelada. Se verificó el cumplimiento de las BPF mediante la planilla de evaluación del MSAS (Ministerio de Salud) de Venezuela y de los POES a través de un cuestionario propuesto por la FDA. Las BPF y los POES fueron evaluados en base a deméritos, se obtuvo un valor en porcentaje por cada pre-requisito y fue referido como efectividad higiénica. Los resultados obtenidos de la evaluación de las BPF indicaron que la planta cumple con la mayoría de las condiciones de edificaciones e instalaciones, equipos y utensilios, requisitos higiénicos de la producción, aseguramiento de la calidad higiénica, almacenamiento y transporte, obteniendo una efectividad higiénica satisfactoria de un 84%. El nivel de cumplimiento de los POES fue de un 53,12% con deméritos en todos los aspectos evaluados, debido a la inexistencia de un documento guía, carencia de controles en el plan de saneamiento y de liderazgo en ejecutar acciones correctivas. Por lo tanto, se diseñó un programa de control sanitario basado en los POES.
Evaluation of prerequisites programs for a HACCP plan for frozen sardine plant. Good manufacturing practices (GMP) and sanitation standard operating procedures (SSOP) are prerequisites programs for the application of the Hazard Analysis and Critical Control Point (HACCP) system as a food safety approach during processing. The aim of this study was to evaluate GMP/SSOP prerequisites in processing line of frozen whole sardine (Sardinella aurita). The GMP compliance was verified according to a standard procedure of the Ministry for the Health of Venezuela, and the SSOP were assessed according to a checklist proposed by the FDA. GMP and SSOP were evaluated following a demerit-based approach. A percentage value was calculated and referred to as sanitary effectiveness. Results indicated that the plant had a good level of compliance with GMP from assessment of buildings and facilities, equipment and tools, hygienic requisites of the production, assurance of the hygiene quality, storage and transportation, and the percentage of sanitary effectiveness was 84%. The level of compliance for SSOP was 53,12 % with demerits found in all assessed aspects consisting of inexistent guidelines, lack of control in the sanitary plan and lack of leadership in applying corrective actions. Thus, an improvement in the plant sanitation program was designed targeting SSOP.
Assuntos
Animais , Humanos , Peixes , Contaminação de Alimentos/prevenção & controle , Inspeção de Alimentos/métodos , Indústria de Processamento de Alimentos/normas , Alimentos Congelados/normas , Contaminação de Alimentos/análise , Inquéritos e Questionários , Venezuela , Microbiologia da Água/normas , Abastecimento de Água/normasRESUMO
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.
Assuntos
Congelamento , Alimentos Congelados , Proteínas , Produtos Pesqueiros/análise , Bicarbonato de Sódio , Tecnologia de AlimentosRESUMO
The present research is an analysis of Spanish sardine fishing (Sardinella aurita) associated with some climatic and meteorologic parameters of the ecosystem from El Morro Nueva Esparta, Venezuela. The catch and environmental data from the area were taken in the period 1996-2000. Catch data as a function of wind speed, sea surface temperature, air temperature and rain were analyzed by means of simple lineal regression and multiple models. We found a positive correlation of catch with wind speed, and a negative correlation with sea surface temperature, air temperature, and rain. The multiple regression model with intercept had a poor fit, therefore, we made a model without intercept, which improve greatly the fit. A selection of the variables using the forward procedure verified that the independent variables "wind speed" and "air temperature" have a significant relation with catch (p < 0.001) at real time. This method suggests that sea surface temperature and rain have little influence on the catch, and suggests a major availability of resources in the months with low air temperature and the highest wind speed (January-June). Rev.
Assuntos
Animais , Ecossistema , Peixes/classificação , Pesqueiros/estatística & dados numéricos , Densidade Demográfica , Estações do Ano , Temperatura , Venezuela , Vento , Água do MarRESUMO
Los cambios físicos, químicos y sensoriales fueron evaluados en filetes de sardina (Sardinella aurita), almacenados en congelación a -18°C por seis meses. Se tomaron muestras mensualmente con el propósito de determinar: pH, color (L, a y b), líquido exprimible (LE), solubilidad de proteínas solubles en soluciones salinas (SPs), ácido tiobarbitúrico (TBA), ácido láctico, perfil de ácidos grasos, humedad y evaluación sensorial. En este estudio el tiempo de almacenamiento mostró diferencias significativas (P < 0,05) con respecto a: color (L, a y b), evaluación sensorial, SPs y LE. La evaluación sensorial resultó ser el parámetro más idóneo para medir la estabilidad de los filetes congelados, los cuales mostraron un excelente grado de frescura, hasta el segundo mes de almacenamiento a partir del cual comienza a decrecer, pero conservando buenas condiciones sensoriales hasta el quinto mes. Al sexto mes se manifestaron alteraciones en el color del músculo, con la aparición de manchas amarillas, debido posiblemente a la oxidación de lípidos. Estos cambios sensoriales fueron confirmados por el índice de TBA, el cual se incrementó de 0,024 (Ab.Und/g), hasta 0,22 al sexto mes. La frescura inicial de las sardinas crudas, su bajo contenido de grasa y una correcta manipulación, fueron los factores que influyeron en la estabilidad del producto final.
Physical, chemical and sensorial changes were evaluated in sardine (Sardinella aurita.) fillets under frozen storage at -18°C for six months. Samples were taken monthly in order to evaluate: pH, colour (L,a, and b), water binding capacity (WBC), solubility of proteins in saline solutions (SPs), thiobarbituric ácid test (TBA), lactic acid, fatty acid profile, moisture and sensory evaluation. In this research the storage time shows significant differences (P < 0.05) with: colour (L,a and b), sensorial evaluation, SPs and WBC. Sensorial evaluation was the most suitable parameter in measurement frozen fillets stability. Fillets showed an excellent grade of freshness, until second month of frozen storage. After that, quality decrease, but also can reach until fifth month, with good sensorial conditions, meanwhile at sixth month, muscle colour was alterate with yellow spots, maybe due by lipid oxidation. These sensorial changes were confirmed by TBA index, which increase from 0.024 (Ab.Und/g) at the beginning of this experience, until 0.22 al sixth month. The initial freshness of raw sardine, the low fat level (2.5%), and good manipulation were important factors that influence in the stability of the end product.
RESUMO
Frequency of contamination by psychrotrophs, mesophiles, fecal coliforms, Staphylococcus aureus and Salmonella was investigated in 110 samples of commercially available sardines (Sardinella aurita) in the city of Londrina, Parana. Of the populations sampled, the psychrotrophs and mesophiles in the counts of above 106 UFC/g were present in 30(27,28%) and 68 (61,68%), respectively. Fecal coliforms above 100/g were attained in 36(32, 73%) samples. While, S. aureus in counts of above 106 UFC/g was isolated from 47(42, 72%) of the samples; the presence of Salmonella could be demonstrated through the experimental method used.
Foram examinadas 110 amostras de sardinha (Sardinella aurita) coletadas em peixarias, supermercados e feiras-livres de Londrina, Paraná, quanto à contaminação por microrganismos psicotrópicos, mesófilos, coliformes fecais (NMP), Staphylococcus aureus e Salmonella. Destas amostras, 30(27,28%) e 68(61,86%) apresentaram contagem de microrganismos psicro-tróficos e mesófilos, respectivamente, superior a 106 UFC/g. Um número de coliformes fecais acima de 100/g foi evidenciado em 36(32,73%) das amostras. Em 47(42,72%) exemplares foi isolado S. aureus em número superiora 106 UFC/g, sendo que em nenhuma amostra foi isolada Salmonella.
RESUMO
Frequency of contamination by psychrotrophs, mesophiles, fecal coliforms, Staphylococcus aureus and Salmonella was investigated in 110 samples of commercially available sardines (Sardinella aurita) in the city of Londrina, Parana. Of the populations sampled, the psychrotrophs and mesophiles in the counts of above 106 UFC/g were present in 30(27,28%) and 68 (61,68%), respectively. Fecal coliforms above 100/g were attained in 36(32, 73%) samples. While, S. aureus in counts of above 106 UFC/g was isolated from 47(42, 72%) of the samples; the presence of Salmonella could be demonstrated through the experimental method used.
Foram examinadas 110 amostras de sardinha (Sardinella aurita) coletadas em peixarias, supermercados e feiras-livres de Londrina, Paraná, quanto à contaminação por microrganismos psicotrópicos, mesófilos, coliformes fecais (NMP), Staphylococcus aureus e Salmonella. Destas amostras, 30(27,28%) e 68(61,86%) apresentaram contagem de microrganismos psicro-tróficos e mesófilos, respectivamente, superior a 106 UFC/g. Um número de coliformes fecais acima de 100/g foi evidenciado em 36(32,73%) das amostras. Em 47(42,72%) exemplares foi isolado S. aureus em número superiora 106 UFC/g, sendo que em nenhuma amostra foi isolada Salmonella.