| Summary: | Dissertação de mestrado integrado em Engenharia Biológica (área de especialização em Tecnologia Química e Alimentar) The increase of fish consumption due to its nutritional characteristics, led to a stimulation of fishing industry, as regards the improvement of the processes for its conservation. Freezing and glazing are techniques commonly used in reducing the incidence of fish deterioration processes. In order to find an alternative to complement freezing and replace water glaze, the present work aimed at evaluating the effect of edible coatings of 0.5% and 1.5% chitosan on the quality of frozen fish. Both coatings - water glazing and chitosan coatings - were applied directly on Atlantic salmon (Salmo salar) frozen and stored for 6 months at -22 °C. Comparing both coatings with each other and with control uncoated samples, several parameters such as coating/glazing loss, weight loss, drip loss, TVC, TBA, TVB-N, K-value, pH and color coordinates L*a*b* were periodically evaluated. Favorable results were found for salmon samples coated with 0.5% chitosan in the control of coating loss and for the samples coated with 1.5% chitosan in maintaining the color of the salmon and controlling microbial contamination of samples frozen and thawed. In this work several parameters, such as coating loss, weight loss, drip loss, TVC, TBA, TVB-N, and K-value maintained quite stable due to the protection provided by a correct freezing temperature and a suitable control of its maintenance. O aumento do consumo de peixe, devido às suas características nutricionais, obrigou a uma dinamização da indústria do pescado, no que respeita ao melhoramento dos processos de conservação do mesmo. A congelação e a vidragem são técnicas comumente usadas na redução da incidência dos processos de deterioração no pescado. Com o objetivo de encontrar uma alternativa que complementasse a congelação e substituísse o vidrado de água, o presente trabalho visou avaliar o efeito da aplicação de revestimentos edíveis de 0.5% e 1.5% de quitosano na ...
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