The present paper reviews the results of research work conducted by the present author's group in the area of thermal process lethality estimation and of heat transfer in food undergoing thermal processes. The reviewed work includs: F_p estimation based on the application of two theorems, process variability estimation, empirical temperature history and heat transfer in a food particle and liquid mixed package. The paper ends with discussions and concluding remarks by highlighting reviewed results of potentially wide interests.

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Mid infrared (MIR) spectroscopy theoretically has advantages with respect to spectral information in comparison with near-infrared spectroscopy, though it has been very difficult to obtain the useful spectrum from wet materials such as foods because of the strong absorption of MIR radiation by water. In parallel with the development of Fourier transform infrared (FT-IR) technology, various sampling techniques, for example; attenuated total reflection (ATR), diffuse reflection, and photoacoustic methods, have evolved, and provide FT-IR spectroscopy with substantial potential as a qualitative and quantitative analytical tool for food processing. In this review, recent developments in mid-infrared spectroscopy, particularly FT-IR/ATR methods, have been taken an overview of sugars focusing on its applications to qualitative and quantitative analysis of foods and agricultural products. In addition, this paper reviews the applications of FT-IR/ATR methods to monitoring metabolisms of cultivation processes and these studies represented an important step in the development of nonintensive on-line monitoring devices for food processing and bioprocesses. Furthermore, we survey the importance of infrared spectroscopic characteristics of foods in order to evaluate the effects of application of infrared irradiation to thermal operations in food process such as heating and drying.

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An empirical equation is available for predicting apparent water diffusivity in rice starch/water system in arbitrary moisture content and at arbitrary temperature. In the present paper, water diffusivity in wheat starch (wheat flour) /water system was measured by PFG-NMR (pulsed field gradient-nuclear magnetic resonance) . The result of experiment suggested that the predicting equation for water diffusivity in rice starch/water system could be applied for that in wheat starch (wheat flour) /water system.

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Methods for pressure drop estimation of non-Newtonian power law fluids in tube flow are reviewed. Pressure gradients and the corresponding mass flow rates of five different non-Newtonian fluid foods: 1% solutions of sodium alginate and CMC, 1.5% CMC solution, two different tomato ketchups, oyster sauce, in four different diameter stainless steel tubes ranging from 7.51 to 16.34 mm i.d. were recorded using a continuous flow tube viscometer capable of operating in both transient and continuous flow modes. The fluids were pseudoplastic in nature and followed the power law model. The flow was confined to the laminar flow regime and appreciable slippage occurred in all cases. Power law parameters, based on tube flow and low shear rate rotational viscometer were determined and compared. These power law parameters failed to give the classical relationships proposed by Dodge and Metzner [1] . Empirical equations were developed to correlate power law parameters based on low shear rate rotational viscometer to the ones based on tube flow viscometer. Pressure drop estimations based on the empirical equations followed the experimental values with 13% average absolute error.

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The effects of added salts on the solution properties of silk Fibroin in water were investigated by the static light scattering method. Silk Fibroin was extracted from sericin-removed yarn by 35% calcium chloride at 98°C for 6 h. Fibroin solution was obtained by dialysis of the resultant extract against distilled water at 4°C. All the experiments were done using 6% Fibroin solutions at 25°C. Monovalent salts such as NaCl and KCl induced the formation of disorderly structure via the aggregation of Fibroin molecules. On the other hand, the phase separation was observed in the presence of divalent salts such as CaCl₂ and MgCl₂. This phase separation may be attributed to the intermolecular interaction of Fibroin strengthened by the bridging effects of divalent salts. The relative viscosity of fibroin solution depended on the salts, but did not correspond to the difference in the valence of salts and the solution properties of fibroin. These results indicated that the divalent salts-induced phase separation of fibroin solution occurred in the micro-region within colloidal particles thereby not affecting viscosity strongly.

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