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Many studies have shown that marine phospholipids (MPL) provide more advantages than fish oil. They have better bioavailability, better resistance towards oxidation and higher content of eicosapentaenoic acids (EPA) and docosahexaenoic acids (DHA) than oily triglycerides (fish oil). The objective of this study is to investigate the oxidative and hydrolytic stability of MPL. In addition, this study also investigates the effect of chemical composition of MPL and Maillard reaction (interaction between lipids oxidation products with the residue of amino acids) on MPL emulsions’ stability. Firstly, MPL were prepared in the form of emulsions by high pressure homogenizer. Then, the oxidative and hydrolytic stability of phospholipids was investigated by measurement of simple chemical analyses such as Peroxide Value and Free Fatty Acids, and 31PNMR after 32 days storage at 2ºC. The oxidative stability of MPL was further investigated through measurement of secondary volatile compounds by Solid Phase Microextraction at several time intervals. On the other hand, the Maillard reaction was investigated through the measurement of color changes and pyrrole content before and after 32 days storage. Preliminary result suggested that MPL emulsions have good hydrolytic stability and relatively good oxidative stability as compared to fish oil containing emulsions. As a conclusion, MPL with different chemical compositions have affected emulsions’ stability differently.

Marine phospholipids (MPL) are believed to provide more advantages than fish oil from the same source. They are considered to have a better bioavailability, a better resistance towards oxidation and a higher content of polyunsaturated fatty acids such as eicosapentaenoic (EPA) and docosahexaenoic acids (DHA) than oily triglycerides (fish oil). Therefore, the objective of this study is to explore the feasibility of using marine phospholipids emulsions as delivery system through investigation of the physical, oxidative and hydrolytic stability of MPL emulsions with or without addition of fish oil. The effect of initial Peroxide Value, total lipids, phospholipids and antioxidants content on stability of MPL emulsions were studied. The physical stability was investigated through measurement of particle size distribution and creaming stability, which involve measurement of changes (%) in emulsion volume. In addition, preliminary investigation of the oxidative and hydrolytic stability was carried out through determination of Peroxide Value and Free Fatty Acids Value after 32 days storage at room temperature and 2ºC, respectively. Oxidative stability of MPL emulsions were also investigated through measurement of secondary volatile compounds by Solid Phase Microextraction at several time intervals at 2°C storage. Preliminary results showed that marine phospholipids emulsion has a good oxidative stability.

The aim of this work was to study which effects protein and lipid source in feed for organic rainbow trout (Oncohynchus mykiss) may have on the sensory quality of the final product after up to 14 days of storage in ice. The protein sources used in the experiment were fishmeal and a mixture of vegetable protein. While the lipid sources were fish, linseed, sunflower, rapeseed and grape seed oil. After slaughtering all fish were frozen (-40°C) until the sensory experiment was performed, for which the trout were thawed and stored for 3, 5, 7 and 14 days in ice respectively. The sensory experiment included objective sensory profiling, of samples which were heat treated in a convention oven at 100°C until the core temperature was 70°C. The sensory panel consisted of 11 assessors which all were tested and trained. The sensory analysis included descriptors related to the odour, appearance, flavour and texture. After 3 days of storage in ice an impact of lipid source is seen. Inclusion of linseed oil resulted in a sensory profile comparable to the use of fish oil in the feed. While some of the other vegetable oils, especially grape seed oil results in a sensory profile rather different from the trout that had fish oil. However, this difference observed after 3 days of storage did not appear after a longer storage time, and consequently no differences in the sensory characteristics is observed after the 5 days of storage in ice. Nevertheless after 7 days in ice some differences are appearing again. Here the trout which have had rapeseed and grape seed oil in the feed has a more neutral flavour and odour compared to the other ones. After 14 days of storage the protein source had an effect, and the trout which received fishmeal in the feed were more tainted. Therefore, it is seen that the shelf-life is increased by feeding the fish with vegetable protein compared to fish meal. The conclusion of the experiment therefore was that both dietary vegetable protein and lipid sources c

Mackerel are usually caught in the autumn and often frozen either on board the fishing vessel or soon after landing. Due to the seasonality of the catching period, mackerel can be stored frozen for a long time period before entering the production chain. However, frozen storage of fatty fish such as mackerel can lead to a significant loss in fish quality primarily due to oxidation of the long chain omega-3 fatty acids. These quality changes results in significant loss for the fish processing industries and in fish with poor eating quality. In order to investigate batch-to-batch variation due to different catching methods and different freezing procedures 6 batches of frozen mackerel were obtained from the local producer of caned mackerel. Fish were processed as soon as possible after landing i.e. headed, gutted and individually frozen at the industry. However, one of the catch was abused and stored on ice for 8 days before entering the production line. Subsequently, samples from the catches were sent to our laboratory where they were stored frozen at -30 °C for a period of 12 months. At intervals of 6 weeks samples were taken and analysed for proximate analysis as well as for oxidative deterioration and texture changes. The aim was to investigate the correlation between the raw material history and the quality loss observed during frozen storage using relevant multivariate data analysis such as Principal Component Analysis (PCA) and Partial Least Square Analysis (PLS). Preliminary results showed that it was possible to differentiate between the different batches depending on their history and that some batches were more oxidised than others. Furthermore, based on the results from the data analysis, critical control points in the entire production chain will be identified and strategies to prevent quality loss proposed.