The purpose of this study was to analyze the effect of 10-min continuous pressure and pulsed pressure in two 5-min steps (400 MPa at 7 degrees C) on the microbial flora, total volatile bases, pH, and texture of purified and unpurified oysters. High-pressure treatment reduced the number of all the target microorganisms (total viable count, H2S-producing microorganisms, lactic acid bacteria, Brochothrix thermosphacta, and coliforms), in some cases by around 5-log units. The difference between the counts in the control and the pressurized oysters remained stable throughout 41 days of storage at 2 degrees C. No Salmonella spp. were detected in either the control batch or the pressurized batches during this storage period. Deterioration of the oyster was accompanied by increased total volatile bases, mainly in the nonpressurized samples. The pH was practically constant in the pressurized oysters and fell slightly in unpressurized samples. As for mechanical properties, shear strength values were higher in pressurized than in unpressurized oysters. Step-pulse pressurizing (400 MPa at 7 degrees C in two 5-min pulses) produced no apparent advantages over continuous pressurizing based on any of the indices used.

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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

Heat-and high-pressure-induced gels were prepared from blue whiting muscle (Micromesistius poutassou R.). Minced muscle was homogenized with salt (1% NaCl), and response surface methodology was used to determine the influence of pressure, time, and temperature on the work of penetration. Two combinations of pressure−time−temperature were chosen to give the highest work of penetration, and samples were compared with a heat-induced gel. The following lots were subjected to chemical and rheological analysis: 200 MPa, 3 °C, 10 min (lot L); 375 MPa, 38 °C, 20 min (lot H); and atmospheric pressure, 37 °C, 30 min/90 °C 50 min (lot T). Breaking force, deformation, and cohesiveness were greater in gels of lot L. Hardness and water holding capacity were greatest in gels of lot T. Elasticity was greater in high-pressureinduced gels. The percentage of hydrophobic interactions, essentially linking actin molecules, was greater in gels of lot H than in gels of lots T and L. There were more cross-linkages in the heat-induced gels (lot T).

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