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O azeite e o pescado são dois importantes constituintes da Dieta Mediterrânea, dado as suas propriedades altamente nutritivas e saudáveis. Estes dois produtos muito ricos, podem ser misturados como forma de complemento, um ao outro. A inovação e a qualidade dos produtos têm sido, nos ultimos anos, alvo de procura dos consumidores, nesse sentido, as industrias do pescado têm trabalhado formas de inovar e aumentar a qualidade dos seus produtos para responder às exigencias dos consumidores. Assim, com a presente dissertação procurou-se estudar o efeito da utilização de diferentes azeites virgem extra, como líquido de enchimento, nas características físico-químicas e sensoriais em conservas de atum, e relacionar estes, com o azeite refinado e o óleo vegetal. Além disso, estudou-se o efeito do tempo de prateleira no T0 (15 dias) e T6 (6 meses), quer à temperatura ambiente, quer em condições de aceleração a 50º. Foram utilizados diferentes azeites virgem extra com crescentes intensidades de frutado maduro, verde suave e verde intenso. Os parâmetros avaliados incluíram no atum a atividade antioxidante, cor, textura, pH, humidade e cinzas, bem como as características sensoriais; no óleo de girassol e nos azeites a atividade antioxidante, parâmetros de qualidade, estabilidade oxidativa e análise sensorial. Os resultados obtidos mostraram que os azeites/óleo de girassol, após o processamento possuem menor estabilidade a nível da atividade antioxidante, no entanto verificou-se que o azeite verde intenso é o azeite que possui maior atividade antioxidante comparativamente com as outras amostras, seguido do verde suave. O atum em contato com o óleo de girassol e os azeites, perdeu a consistência ao longo do armazenamento, em contrapartida, houve um aumento na intensidade dos outros atributos (p.e. suculência), para o T0 (após os 15 dias de enchimento) e T6 (após os 6 meses de enchimento). Nos parâmetros, como a agradabilidade do sabor e do aroma, e intensidade, o óleo de girassol e os azeites tiveram valores muito próximos, mas nas conservas de atum em contato com o óleo de girassol e o azeite refinado foram obtidas maiores intensidades para quase todas as amostras (T0 e T6). Constatou-se ainda que o tratamento térmico diminui a qualidade das amostras e que a diferença foi mais expressiva para as amostras no T6, principalmente à temperatura de 50ºC (teste de aceleração). De uma forma geral pode-se dizer que a utilização dos azeites com intensidades de maduro, verde suave e verde intenso, em comparação com o azeite refinado e o óleo de girassol (comumente utilizado), acresce qualidade nutricional e organolética às conservas de atum. Os azeites virgens extra verde intenso e verde suave demostraram ser os azeites mais promissores.
Olive oil and fish are two important constituents of the Mediterranean Diet, given their highly nutritious and healthy properties. These two highly rich products can be mixed as a complement to each other. The innovation and quality of products has been, in recent years, a target of consumer demand and in this sense fish industries have been working on ways to innovate and increase the quality of their products to meet the consumers expectations. Therefore, in this work we study the effect of the use of different extra virgin olive oils, as a filling liquid, on the physical and sensory characteristics in canned tuna, and to relate these to refined olive oil and vegetable oil. Furthermore, the effect of shelf life as evaluated at T0 (15 days) and T6 (6 months), either at room temperature, or under acceleration conditions at 50°C. Different extra virgin olive oils were used, with increasing intensities of ripe fruit, soft green and intense green. The parameters evaluated in tuna included antioxidant activity, color, texture, pH, moisture and ash, as well as sensory characteristics; in sunflower oil and olive oils the antioxidant activity, quality parameters, oxidative stability and sensory analysis. The results showed that olive oils / sunflower oil, after processing, have less stability in terms of antioxidant activity, however it was found that intense green olive oil is the oil that has higher antioxidant activity, followed by mild green. Tuna in contact with sunflower oil and olive oils lost consistency during storage, on the other hand, there was an increase in the intensity of other attributes (e.g. succulence) in relation to tuna (raw material), for T0 (after 15 days of filling) and T6 (after 6 months of filling). Regarding parameters such as pleasantness of flavor and aroma, and intensity, sunflower oil and olive oils have very similar values, but for canned tuna in contact with sunflower oil and refined olive oil, higher intensities were observed for almost all samples (T0 and T6). It was also found that the heat treatment decreases the quality of the samples and that was more expressive for the samples in T6, mainly at a temperature of 50ºC (acceleration test). In general, it can be said that the use of oils with intensities of ripe, soft green and intense green, compared to refined olive oil and sunflower oil (commonly used), adds nutritional and organoleptic quality to canned tuna. Intense green and soft green extra virgin oils proved to be the most promising oils.
Olive oil and fish are two important constituents of the Mediterranean Diet, given their highly nutritious and healthy properties. These two highly rich products can be mixed as a complement to each other. The innovation and quality of products has been, in recent years, a target of consumer demand and in this sense fish industries have been working on ways to innovate and increase the quality of their products to meet the consumers expectations. Therefore, in this work we study the effect of the use of different extra virgin olive oils, as a filling liquid, on the physical and sensory characteristics in canned tuna, and to relate these to refined olive oil and vegetable oil. Furthermore, the effect of shelf life as evaluated at T0 (15 days) and T6 (6 months), either at room temperature, or under acceleration conditions at 50°C. Different extra virgin olive oils were used, with increasing intensities of ripe fruit, soft green and intense green. The parameters evaluated in tuna included antioxidant activity, color, texture, pH, moisture and ash, as well as sensory characteristics; in sunflower oil and olive oils the antioxidant activity, quality parameters, oxidative stability and sensory analysis. The results showed that olive oils / sunflower oil, after processing, have less stability in terms of antioxidant activity, however it was found that intense green olive oil is the oil that has higher antioxidant activity, followed by mild green. Tuna in contact with sunflower oil and olive oils lost consistency during storage, on the other hand, there was an increase in the intensity of other attributes (e.g. succulence) in relation to tuna (raw material), for T0 (after 15 days of filling) and T6 (after 6 months of filling). Regarding parameters such as pleasantness of flavor and aroma, and intensity, sunflower oil and olive oils have very similar values, but for canned tuna in contact with sunflower oil and refined olive oil, higher intensities were observed for almost all samples (T0 and T6). It was also found that the heat treatment decreases the quality of the samples and that was more expressive for the samples in T6, mainly at a temperature of 50ºC (acceleration test). In general, it can be said that the use of oils with intensities of ripe, soft green and intense green, compared to refined olive oil and sunflower oil (commonly used), adds nutritional and organoleptic quality to canned tuna. Intense green and soft green extra virgin oils proved to be the most promising oils.
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Keywords
Conservas Pescado Azeite virgem extra Valorização