For the purpose of constructing rational design method for food manufacturing processes, three types of research works have been done. The first type was enzymatic syntheses of food related materials in organic solvent including sweetener, oligo-peptides, and edible surfactants, which might contribute to up stream treatment for the process. The second type works were for down stream treatment. Those were designing of liquid chromatograph as separation operation and of freeze concentration as concentration operation. In the third, target oriented research work was proceeded on. The target was the further enhancement of high functionality of liquid lipids that possess it already by encapsulation into polymer wall materials. The oxidation of lipids composed of poly unsaturated fatty acids were retarded and the encapsulated W/O/W emulsion with glycerides composed of medium chain fatty acids as oil phase enhanced the absorption of hydrophilic physiological substances dissolved in inner water phase. Finally, the common physico-chemical phenomena encountered during the long research works were described. Those were the kinetic model of the chemical reaction with variety of interactions with surrounding molecules or functional groups and the enthalpy-entropy compensation.

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Enthalpy relaxation behavior of Katsuobushi (dried glassy bonito meat) during several storage conditions below its T_g was studied by differential scanning calorimetry (DSC) . The magnitude of the relaxed enthalpy (Δ H) became larger with the increase in aging time, and the relaxation speed became faster with the increase in aging temperature. This tendency was quite similar to other amorphous materials. The process of the ΔH change during aging could be fitted successfully to the Kohlrausch-Williams-Watts (KM/WI) equation, which was often used to describe the kinetic process of enthalpy relaxation for many amorphous polymers. The mean relaxation time constant that was calculated through the fitting process suggested that the glassy state of Katsuobushi was easy to relax as compared with sucrose and starch. Furthermore, it was observed that aging process reduce the water sorption ability of Katsuobushi. This suggested that physical properties of food could be changed even if it is stored in the glassy state.

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Using FT-IR spectrometer and attenuated total reflection techniques, we provided three midinfrared spectral extraction methods of ionic dissociative metabolites by focusing our attention on the mixture of glucose 6-phosphate (G6P), fructose 6-phosphate (F6P) and Tris buffer, in which the phosphoglucose isomerase reaction was assumed. The extraction method 1 was based on the spectra for the mixtures, and considered the possible interaction between the metabolites. The method 2 used the spectra for the independent aqueous solutions. The method 3 was based on the spectra for the mixture, from which the spectra of the Tris buffers were subtracted, and might be applicable to the quantification for the system in which almost all the components except for the objective ones could not be specified. By using the spectra of the ionic species extracted by the three methods, we could accurately estimate the pH value and each reagent concentration in the G6P-F6P-Tris mixture.

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Characteristics of a spiral electrode sterilizer by applying high voltage pulse were studied experimentally. The reactor was consisted of two spiral wires that were connected to pulse source and ground. The survival ratios of Escherichia coli K-12 were obtained with varying applied pulse peak voltage, capacitance of pulse forming capacitor, electric conductivity of suspension, reactor volume, and electrode material. The survival ratios were decreased with increasing pulse peak voltage and capacitance value, however, they were dependent on the input electrical energy calculated by applied voltage and pulse forming capacitor. When 300 J/mL of electrical energy was applied, 10^-5 of survival ratio could be achieved, independent of the applied voltage and pulse forming capacitor. Electrical conductivity of the liquid greatly affected to the survival ratio where the sufficient inactivation was achieved less than 4 mS/cm. Reactor volume and electrode connection of the reactor did not affect to the survival ratio.

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The hyaluronidase-mediated degradation of hyaluronic acid to hyaluronic acid oligosaccharides was investigated. The final products of the batch reaction were the tetrasaccharide and hexasaccharide only. In the reaction solution containing an inorganic salt such as NaCl, the yield of hexasaccharide was higher than that of tetrasaccharide. However, in the absence of inorganic salt, the tetrasaccharide was generated preferentially. The yield of each oligosaccharide depended on the nature of the inorganic salt used. In the batch reaction, the product yield was approximately 60%. However, a continuous reaction increased the yield to about 85% within the first 200 h of operation.

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