The present paper reviews research results mostly related to thermal inactivation reaction kinetics that were emanated from work conducted at the present author's laboratory. After completing the review, discussions and future research needs were presented. Discussions include the examination of a widely accepted approach for thermal process evaluation based on the use of a sterilizing value (Fp) . This examination shows that the approach is not valid when the slope (z) of a phantom thermal death time curve and/or the initial curvilinearity parameter (R) of a survivor curve are temperature dependent. The future research needs include reaction kinetic study on thermal lethality enhancement by the thermal shock of microorganisms.
Fermenter scale-up methods based on industrial manufactured records and numerical flow simulation will be introduced. Firstly, we have surveyed basic specifications of 480 industrial fermenters, and obtained standard specifications and their correlations with the fermenter scales. Subsequently, we have investigated recent computerized fluid dynamics, CFD, and applied it to fermenter performance descriptions and compared the results to actual manufactured records and common empirical equations for clarifying the CFD applicability to fermenter scale-up design. For simulation methods, the k-ε model, the dynamical multi-block method and the drift flux model have been used. Comparing with manufactured records and empirical equations, CFD has given the same qualitative trends in the following phenomena. By keeping a gas flow rate constant, increasing a tank aspect ratio gives higher gas hold up; lower power input decreases gas-holdup and insufficient gas bubble circulation under the bottom impeller; flow interference and a power consumption drop are caused by narrow spaced impellers; a larger impeller diameter gives lower local shear stress along with higher impeller flow rate and average shear stress. Finally, fermenter scale-up design guidelines based on manufactured results and CFD have been proposed.
Using thin discoid and slender cylindrical potato samples, the shrinkage data in all three dimensions were obtained experimentally at a temperature of 60°C, a relative humidity of 5%, and an air velocity of 1.6m/sec. The results are expressed as percentage change of lengths in axis and radius during drying. The relationships between volume and directional shrinkage were discussed. Directional shrinkage was correlated to volumetric shrinkage and moisture removal direction. It was observed that the shrinkage coefficient in the axis was significantly different from that in the radius during air-drying. On the other hand, data describing the mechanical characteristics of cylindrical potato samples were experimentally determined at the above drying conditions. The Young's modulus (E), yield stress (σc), fracture stress (σf) were expressed as a function of bulk moisture content (M) . These data for the moisture ranges used in conventional potato drying can help to optimize the drying conditions and the drier design.
The surface tensions of 6-O-hexanoyl, octanoyl, decanoyl and dodecanoyl L-ascorbates, which were synthesized via the immobilized-lipase-catalyzed condensation of ascorbic acid and the corresponding fatty acids in acetonitrile, were measured at 25°C by the Wilhelmy method at their various concentrations, and the critical micelle concentration, CMC, and the residual area per molecule, a, were evaluated for each acyl ascorbate. The CMC was lower for the ascorbate with a longer aryl chain, while the a values were ca. 0.30 nm2 for all the acyl ascorbates.
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