Properties of Kamaboko Made From Red Hake (Urophycis chuss) Fillets, Mince, or Surimi

Fresh red hake (Urophycis chuss) was randomly assigned to three treatments: whole fillets, minced flesh, and surimi. These treatments were stored at −5°C for 10 wk and tested for salt-extractable protein, actomyosin, and Ca⁺⁺– ATPase activity prior to the manufacture of Kamaboko. Kamaboko quality was determined by the fold test and percent expressible fluid. Salt-extractable protein, actomyosin, and Ca⁺⁺– ATPase activity all decreased throughout the storage period and were found to be good measures of the ultimate quality of Kamaboko. The data suggest red hake is suitable for the manufacture of surimi which can be stored frozen and subsequently manufactured into an acceptable Kamaboko.     

Conversion of Quartz to Tridymite

The conditions under which tridymite becomes a stable phase have been reinvestigated. When quartz was heated with 2% alkali oxide, tridymite formed directly at 872° to 898°C. with Na₂O, at 883° to 902°C. with K₂O, and above 1005°C. with Li₂O. Cristobalite occurred as an intermediate phase above 893°C. with Li₂O, above 898°C. with Na₂O, and above 902°C. with K₂O. When quartz plus sodium chloride was heated in vacuum, tridymite did not form but cristobalite started to appear at 1050°C. The results showed that the formation of tridymite can be strictly a solid-state process. New schematic tentative diagrams for the high-silica region of binary systems are suggested. Quartz and cristobalite are regarded as the only stable crystalline phases of pure silica. Tridymite is pictured as a binary incongruently melting phase.     

Effect of Carbon and Water on Wetting and Reactions of B2O3-Containing Glasses on Platinum

Sessile-drop experiments were conducted to analyze the wetting characteristics of molten B₂O₃ and B₂O₃-containing glasses on Pt. In atmospheres free of carbonaceous gases, the contact angle for all glasses on Pt was small and invariant under ambient pressures of 10^-4 torr to 1 atm for the range 700° to 1000°C. Adsorption of carbon at the metal surface decreased the solid/vapor surface energy and increased the contact angle. Carbon was removed by oxidation at a specific ambient pressure, resulting in a reduction in the contact angle. Temperature-pressure data are reported for Pt. Absorption of water vapor by the glasses resulted in a reaction at the solid/liquid interface, spreading of the glass, and adherence. The possible reactions that can occur are given.     

Reaction Kinetics of Polycrystalline Yttrium Iron Garnet

The formation of yttrium iron garnet, Y₃Fe₂-(FeO₄)₃, starting with (1) Fe₂O₃ and Y₂O₃ and (2) Fe₃O₄ and Y₂O₃, was studied as a function of temperature and time by means of magnetic moment and X-ray measurements. The reaction began at 600°C. and was completed at 1200°C. The perovskite phase appeared only between 600° and 800°C. Above 1200°C. only the garnet phase was present. The microwave line width and g -factor at 9303 mc. per second were also measured and related to the preparation variables.     

Reaction and Diffusion in Silver-Arsenic Chalcogenide Glass Systems

The diffusion of Ag from the metal or Ag₂Se in amorphous As₂S₃ and As₂Se₃ at 175°C is accompanied by the reduction of As from a valence of 3+ to 2+ or 2+ to 1 + to maintain charge neutrality in the glass. Only Ag⁺ diffuses at this temperature; all other ions are essentially immobile. An amorphous reaction-product phase is formed in the diffusion zone with a composition range of 28.6 to 44.4 at % Ag. The lower limit corresponds to all As cations of 2+ valence (equivalent to amorphous Ag₂As₂S₃); the upper limit, the maximum solubility of Ag in these glasses, corresponds to all As cations of 1 + valence (equivalent to amorphous Ag₁As₂S₃). The diffusivity of Ag in these glasses at 175°C for concentrations of 10 to 35 at.% Ag is
Sulfide 4× 10⁻¹⁴ exp[(+0.23±0.01)(at.% Ag)]cm²/s
Selenide 2' 10⁻¹¹ exp[(+0.14±0.01)(at.% Ag)]cm²/s     

Oxygen Ion Activity and the Solubility of Sulfur Trioxide in Sodium Silicate Melts

The solubility of sulfur trioxide in sodium silicate melts was determined from 1150° to 1250°C by equilibrating melts in gas mixtures of known contents of sulfur dioxide and oxygen. Sulfate forms according to the reactions: O^2-+ SO₂+ 1/2O₂= O^2-+ SO₃= SO₄^2-. The data obtained at 1200°C were interpreted by the linear equation: log(SO₄^2-) = log( P so₂½ P o₂^1/2) + log Y in which Y is a function of the soda/silica ratio. A series of parallel lines was obtained. Relative free oxygen ion activities calculated for 1200°C were in good agreement with theoretical values calculated from the thermodynamic model of Toop and Samis.     

Influence of Temperature, pH, Water Activity and Antifungal Agents on Growth of Aspergillus flavus and A. parasiticus

Effect of temperature, pH, water activity, and nine antifungal agents on growth of Aspergillus flavus and A. parasiticus was determined on Sabouraud-Dextrose Agar and on corn. Maximal growth of the two molds occurred at 33°C, the highest temperature used, pH of 5.0 and a_w of 0.99. At 15°C, growth was observed at a_w of 0.95 but not 0.90. Slight growth was observed at an a_w, of 0.85 at 27°C and 33°C. Nine antifungal agents (Botran, Orthocide, Poly-ram 80, Topsin-M, Thiram, Imazalil, sodium propionate, sodium sulfite and DDVP) were tested for inhibition of growth. Activity of the antifungals increased as the a_w was decreased. All antifungals showed inhibitory activity, but Imazalil and DDVP were the most effective agents at the lowest concentrations.