THE FREEZING OF WATER IN FISH MUSCLE AND IN GELATIN

Abstract

From the calorimetric measurements of Chipman and Langstroth (4) an estimate is made of the percentage of water frozen at temperatures down to − 20 °C. in samples of muscle from different species of fish. It is pointed out that if such measurements are to be used for the estimation of "bound" water, it must be known what portion of the water is kept from freezing by any inorganic salts that are present. Heat-capacity measurements on a 1.7% sodium chloride solution are given, and are shown to agree well with values calculated from available thermal data with the aid of the freezing-point curve. Heat-capacity curves for dry gelatin and 20, 40 and 66% gels are given. The unfrozen water in these gels at temperatures down to − 20 °C. is estimated and compared with results obtained by other methods.