To confirm the formation process of three coffee brown pigments A, B and C, which were produced by thermal reaction between chlorogenic acid and sucrose during roast, the pigments B and C were isolated by Sephadex G-25 column chromatography from roasted coffee beans or the brown product obtained by heating the mixture of chlorogenic acid and sucrose using the model roast method. Pigment B or C was heated at 170°C by the improved model roast method and analyzed to clarify the time course of the change of B or C. Dark brown pigment A was formed from red brown pigment B and B was from yellow brown pigment C. These results show the formation process of three pigments as follows: Moreover, it has been observed that (i) the interconversion of the pigments was ceased when the reaction mixture dried, (ii) retention time of C produced by the model roast method on the Sephadex G-25 column chromatography became smaller as the roast proceeds, and (iii) citric acid in Mcllvain buffer promoted the browning but was not necessary for the formation of three pigments.

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"N-Material"is a proteinaceous substance which has the appearance of turbidity when soysauce is diluted and successively heated. This material appears in case of improper cooking treatment of soybeans. Conventionally, an amount of "N-Material" in an enzymatic digest of cooked soybeans or in soysauce has been assayed by turbidimetry after being diluted with water and then heated. The application of this method to a filtrate of Moromi-mash or unpasteurized soysauce has been impossible because of the formation of heat coagula. We proposed a new assay method for "N-Material" in any sample obtained during soysauce manufacturing process including a filtrate of Moromi-mash and unpasteurized soysauce. This method is more rapid and more sensitive than the conventional one, and can be effectively used in the process control of soysauce manufacturing. For preparing the enzymatic digest of cooked soybeans, the test sample was incubated in 0.2M phosphate buffer (pH 7.0) with the crude protease (300PU/ml) of koji-mold, Asperqillus sojae, at 40°C for 2h followed by filtration. The "N-Material" in the each sample was assayed by a high-speed gel filtration method under the following conditions: column; TSK-G 3000SW (7.5×600mm)×2, elution; 10mM phosphate buffer (pH 6.5), and expressed as a peak height (mm). One millimeter of a peak-height corresponded to 0.0123 mg of "N-Material". By using the new assay method it was shown that an amount of "N- Material" at the beginning of brine fermentation, if it existed, decreased to the one-third at the final stage of fermentation after six months.

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Functional properties, especially emulsifying properties of plasma protein and globin obtained from slaughtered porcine blood were investigated. The plasma protein showed higher emulsifying activity than the whole whey protein or casein. The emulsifying activity was paticularly high in the acidic pH region and in the presence of NaCl. Globin also showed an increase in emulsifying activity under acidic conditions. The amount of plasma proteins adsorbed on the emulsified oil surface was greater than that of whey proteins, and plasma proteins was adsorbed more tightly than whey proteins. These suggest that adsorption mechanism of plasma proteins to the emulsified oil surface is different from that of whey proteins. Addition of palmitic acid to the plasma protein caused no significant changes in their emulsifying activity. Emulsifying activity of the plasma protein which was treated with charcoal to remove residual fatty acid was markedly reduced, suggesting that this plasma protein preparation contained some component having good emulsifying activity in itself or some factors affecting the emulsifying activity of coexisting proteins. Unique and good functional properties of blood proteins will be beneficial for their utilization in food processings.

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To estimate the activity of soybean lipoxygenase using a small amounts of sample in a short time, a novel optical electronic system as a single photon counting method was tried. One hundred milligrams of powdered soybean were mixed with 1 ml of 0.2M borate buffer (pH 9.0) containing 1.6mM of luminol and 22.5mM of sodium linoleate in a stainless steel tray (d 50mm, depth 15mm), and placed in a photon counting oven maintained at 27°C. The emission curve obtained was presumed to originate in the reaction of lipoxygenase with linoleic acid, because the addition of erucic acid, an inhibitor of lipoxygenase, abolished the emission, which was restored by the addition of lipoxygenase-I preparation. The order of emission intensity among 4 kinds of soybean breed agreed with the result of the determination of conjugated diene content. These results suggest the possibility of applying the photon counting method for the determination of soybean lipoxygenase activity.

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Effect of the addition of egg white (EW), egg albumin (EA) and soy protein isolate (SPI) on quality of sponge cakes was studied in relation to their concentration. With the increase of protein concentration, air content of batter decreased and viscosity increased in all cases. This tendency was more remarkable in SPI than in EW or EA. Specific volume of the SPI-cakes decreased progressively with increasing protein concentration, while that of EW-or EA-cakes had the maximum value at 7.5% of protein concentration. Through factor analysis, it was suggested that the correlation between attribute in sensory and instrumental evaluation of the EW-cakes was one-dimentioral and texture of the cakes was perceived as a relatively simple system. On the contrary, that of the EA-and SPI-cakes was two-dimentional and texture of the cakes was perceived as a complex system.

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The kinetic determination of ascorbic acid was investigated by using ascorbate oxidase. The initial rate, υ, for 0.1mM ascorbic acid was obtained with ascorbate oxidase on pH 5.6 at 25°C, which was different from those obtained with other reductones (erythorbic acid, reductic acid and triose reductone). Ascorbic acid can be determined kineticaly even in the presence of erythorbic acid, glucose, fructose, sucrose, sodium Lglutamate, glycine, KCI, CaCl₂, FeCl₃, MgCl₂ and NaCl. The sensitivity is estimated to be 0.03mM on pH 5.6 at 25°C.

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Changes of aroma components in the course of processing and with different stewing time in the commercial cooked curry were examined by gas-liquid chromatography. The results obtained were as follows : (1) The aroma components in processing curry, such as β-pinene, cineole, p-cymene and acetoin were rich in low volatile components, linalool and borneol in medium volatile components and cumin aldehyde, anethole, eugenol, iso-thymol and eugenol acetate in high volatile components. The amount of aroma components were found to decreased as the processing time went on. (2) A long time of stewing decreased the amount of low volatile components, while increased the amount of high volatile components. On the contrary, stewing time did not affect the amount of medium volatile components.

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Sugars and starch were analyzed during 6 month' storage (at 13°C) of low β-amylase activity Kyushu No. 98 sweet potato. The following results were obtained. (1) Reducing sugar content remarkably increased from 1.5% (dry basis) to 6.9% during storage of the first one month, and through the remaining storage period, showed high accumulation above 5.0%. (2) Non-reducing sugar content increased linearly from 4.4% to 14.2% during storage. (3) Starch content conversely decreased from 76.8% to 66.7%. (4) These results suggested that changes in sugar and starch content of low β-amylase activity sweet potato during storage were approximately similar to those of old type sweet potatoes. (5) The content of reducing sugar highly accumulated in roots stored for a long period didn't decreased by reconditioning under 20-30°C for 14d ays. (6) β-amylase activity in roots was invariably low during storage therefore, in this sweet potato maltose were not increased by cooking at all times.

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Near infrared reflectance spectra of caffeine and its related compounds such as xanthine, theophylline and theobromine were studied in connection with their chemical structures. A major difference in the spectra was characterized with a difference in the number of CH3 groups contained in the compounds. It has been verified that the near infrared reflectance spectroscopy can be applied to the quantitative analysis of caffeine in green tea.

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Edible protein fibers were produced by a wet Spinning technique from dopes, containing antarctic Krill (Euphausia superba) muscle proteins and Na-alginate, prepared at neutral pH. Spinnability of dopes was closely related to the composition of dopes. For the dopes with low protein contents, good spinnability was only observed when protein/Na-alginate ratios were low. But when protein contents increased, an increasing protein/Na-alginate ratio was required to keep the dopes within the good spinnability zone. As protein/Naalginate ratios were 4/1 and 5/1, fibers produced from spinning dopes containing 7% protein showed adequate strength. Variations of fiber strength due to changes in such process variables, as protein and Na-alginate contents in the dopes, CaCl₂ concentration and pH of the coagulation solution, were monitored. Results predicted by Sheffe's Simplex Lattice Design showed that satisfactory products were acquirable by extrusion of the dope, containing 7% protein and 1.8% Na-alginate, into a weak basic coagulation solution of 3.8% (w/v) CaCl₂. Addition of reducing agents to the dopes lowered the fiber strength. Recovery of proteins increased with the increases of Na-alginate content in the dope and CaCl2 concen-

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