Food preservation technologies to increase the shelf-life of fresh fish products

• Autor(a) principal: Gomes, Bruna Campos
• Data de Publicação: 2022
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/37877
• topic: High pressure processing; Fish; Fish shelf-life; Hyperbaric storage

Fresh fish is a highly consumed food all over the world due to its nutritional value. However, is a high perishable food and highly depends on refrigeration, a method limited by short shelf-life and energetic costs and related environmental issues. In order to meet the consumers demands, in the last years new non-thermal preservations technologies, such as high-pressure processing (HPP), have been developed offering the possibility to extend fish products shelf-life. In this way, this work aimed to extend the shelf-life of fresh salmon using both HPP. In a first phase the objective was to find alternatives to mask or minimize the changes that HPP causes in the appearance and texture of fish. For that three alternatives were studied: (1) the development of coverages or sauce dressings with ingredients that could “hide” the salmon or at least disguise the color changes, (2) the use of phosphates, that are well known for its capacity to retain water in food products, to try reduce the textural hardness caused by pressure and, at last, (3) the use of astaxanthin, the pigment that gives salmon its characteristic red color; until find the best solutions - cheese and salmon puff pastry (Prototype A) and salmon marinade olive oil with pepper paste (Prototype B) - that undergone HPP at 500 MPa for 3 min at RT in order to confirm that is was possible to obtain a shelf-life extension. The objective was accomplished, and a shelf-life of 14 days was obtained for both prototypes. Prototype A microbial counts were lower than Prototype B, however it was not a big difference, and the microbial loads were always below the limit value for all tested microorganisms. Also, this condition caused an inactivation of Pseudomonas spp. to values below the detection limit, in both samples and for all days of storage (14 days). Additionally, physicochemical parameters were evaluated, however, the results did not allow always straightforward conclusions and not always met other authors conclusions. Interestingly, HPP at 500 MPa/3 min together with the culinary ingredients used, was found to be effective in controlling histamine production. Other experiments with HPP were also performed such as: the shelf-life extension of cooked salmon through HPP; the same conditions applied in salmon (500MPa/3 min) were applied in different fishes namely Nile perch, Golden Sea bream, and sardine; and the application of HPP to shuck shellfish with mussels, cockles, lobster, shrimp and crab mouths processed at 300 MPa for 3 minutes In addition, in the final phase of the thesis, it was also tested a methodology that is gaining more and more attention, Hyperbaric Storage (HS), in fresh salmon as an alternative to the conventional refrigeration with possibility to increase shelf-life.