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Seafoods possess high nutritional value and moreover offer functional properties. However, fish products do not contain fibre. Fibre is an essential compound in the diet, which has health benefit effects in certain disorders. At the same time, dietary fibres can be an effective tool in seafood processing for improving functional properties such as water binding, gelling, etc. This paper offers a general view of the role of dietary fibres in a food system and discusses the technological and functional roles of different types of fibres of vegetable origin (cereal, fruits) and animal origin (chitosan), with different characteristics, when they are used as ingredients in the development of restructured fish products. WHAT IS DIETARY FIBRE? The way food is perceived in developed countries has changed in the last twenty years, bringing new life to the Hippocratic principle "Let food be thy medicine and medicine be thy food" and following the tradition in oriental cultures of attributing curative and "therapeutic" properties to foods. The upshot has been awareness of the need to use diet as a means of staying healthy. This tendency has brought with it the concept of functional

Low field NMR T2 transverse relaxation measurements were performed on muscle samples from sixty hake (Merluccius merluccius, L.). Fish fillets from hake stored in ice for 3 and 14 days were subjected to different freezing methods (air blast, liquid nitrogen or walk-in freezer) and storage conditions (-20 and -10°C for 5 days, 8 and 18 weeks). Distribution analysis of T2 data of unfrozen muscle displayed a major band (T21), accounting for 90-92% of the total signal, with a relaxation time centred at 47-60 ms and a broad band with protons of higher mobility between 300 and 800 ms, accounting for 3-5% of the signal. Upon freezing, T21 became wider and an extra band appeared within the range 120-360 ms. Whereas no changes were detected at -20°C, the T21 time constant decreased during frozen storage at -10°C in a similar way for all three freezing methods. The relative abundance of T21 declined with storage time but differences were found as a function of freezing. Results are discussed in the light of morphological alterations and protein denaturation, and it is concluded that LF NMR relaxometry is sensitive to different freezing and frozen storage conditions which can have important implications for the quality of fish muscle.

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