The effects of shortening and monoglyceride on bread staling were investigated using white bread made by a straight dough method. In order to elucidate staling mechanism more precisely, a kinetic model was applied to analyze the staling rate of bread and retrogradation rate of amylopectin. The results were summarized as follows : (1) Shortening had no influence on the staling rate constant in bread. However, monoglyceride decreased the staling rate to about 60% of the control. (2) The effect of shortening on the reduction of crumb firmness was due mostly to a decrease in the difference between limiting value (F_L) and first value (F₀) in crumb firmness, which was caused by an increase of loaf volume and fine crumb structure. (3) The effect of monoglyceride on the decrease of staling rate was mostly resulted in a decrease of retrogradation rate constant of amylopectin. The extreme decrease of crumb firmness was due mainly to the more decrease in the difference between FL and Fo than that of retrogradation rate. The main factor governing the decrease in the difference between FL and Fo was due to the reduction of starch gelatinization and elution in bread.

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Effects of sucrose, glucose, urea and guanidine hydrochloride on dynamic elasticity of gellan gum gels, with and without potassium chloride or calcium chloride, were studied. The dynamic Young's modulus E' of gellan gum gels without and with the salts decreased with increasing concentrations of sucrose or glucose. Urea weakened the gelling ability by breaking hydrogen bonds. Urea strengthened the gel-forming ability of gellan gum gels containing excessive potassium chloride or calcium chloride. Guanidine hydrochloride promoted the gel-forming ability by the aggregation of double or single helices of gellan gum molecules, up to a certain amount, but excessive addition of guanidine hydrochloride weakened the gelling ability of gellan gum gels with and without potassium chloride. Guanidine hydrochloride weakened the gelling ability of gellan gum gels with calcium chloride. It is suggested that a small amount of guanidine hydrochloride shields the electrostatic repulsion between carboxyl groups in gellan gum molecules and increases the number of junction zones. However, higher excessive amount of guanidine hydrochloride disrupts hydrogen bonds and weakens the gel-forming ability.

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Black spots are often developed on the surface of frozen pie sheets during refrigeration before using. Investigation on the nature and the mechanism of the appearance of the black spots showed the following results: no typical microorganisms were observed, but wheat bran was observed in every black spots by an electron microscope, and inhibitors of polyphenol oxidase enriched in wheat bran could delay or inhibit the appearance of the black spots. These results show that polyphenols and polyphenol oxidases contained in the bran contaminated in wheat flour are the cause of the black spot formation. Furthermore, one isozyme of polyphenol oxidases in the bran was determined as a causative enzyme from the inhibitory pattern of various inhibitors on polyacrylamide gel electrophoretic analysis of bran extracts. Several inhibitors containing cysteine and an extract of garlic were efficient for use in inhibiting the formation of black spots without impairing taste and texture of baked pies.

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The change of content and component of dietary fiber in onion (Allium cepa L.) during storage was studied. The relationship between dietary fiber content and hardness of onion was also researched. Dietary fiber was determined by two different methods. Fresh onions were dried to about 92% moisture suspending in the shade and stored at 0°C for 5 months. The following results were observed; The value of total dietary fiber by the PR0SKY's method was 1.2-1.3 times higher than that by KAINUMA'S modified method, and there was correlation between these values. A negative correlation existed between the total dietary fiber content and penetration force, as the onions with higher total dietary fiber content being harder. The dietary fiber changed during storage. For example, the dried-onion (after suspension) concluded higher pectin and cellulose, and the pectin in stored-onion at 0°C changed to insoluble.

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In order to recover glutaminase added to koji hydrolysate before alcohol fermentation through bioreactor, we investigated the enzyme immobilized on a magnetic support prepared from partially deacetylated chitin (PDAC), chitosan and Fe3O4. The magnetic support (MC4P) was superior in endurance to high salt concentration in the solution over a long period. The MC4P was easily recovered by magnetic force. Glutaminase (15 U) immobilized on MC4P (1g) under suitable preparation condition expressed 100% enzyme activity compared to free enzyme. Glutaminase activity immobilized on MC4P was stable in the 15% NaCl solution for 36 days.

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The promoting effect of chicken egg yolk lipoprotein (YLP) on the growth of a human histocytic lymphoma cell line (U-937), a human monocytic leukemia cell line (THP-1), a U-937-derived macrophage-like cell line (U-M), and three human-human hybridomas was examined. YLP was found to have the promoting activity on the growth of U-937, THP-1, U-M and hybridomas. YLP was separated into four fractions by an ultracentrifugation. Among them, YS-1 fraction which was shown to be composed of LDL and a small amount of protein promoted the growth of U-937 cells most significantly. From these results, one of promoting principles of YLP on the growth of human lymphocytic cell lines was suggested to be LDL fractions of YS-1.

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The keeping quality of shredded cabbage was attempted by preserving it in air-exposure at low temperature (1°C) after processing. (1) The weight of shredded cabbage decreased 2, 3, 4 and 5% after the treatment for 1, 2, 3 and 4 hours, respectively. According to a sensory test for appearance of shredded cabbages, after the treatment for 2 hours the evaluation of air-exposure treated samples was lower than control (untreated samples) on wilting. However, overall evaluation was almost same. There was little appearance change until 7day, but on the 15day the evaluation of treated samples stored at 1°C was higher than the control in browning, rot, off-flavor and overall. Appearance deteriorated remarkably during storage at 20°C, but the evaluation of treated samples was higher than the control through the storage period. (2) Changes in contents of phenolic substances, sugars, free amino acids and ascorbic acid were a little, and no differences in their content were observed between the control and the treated samples during storage at 1°C or 20°C. (3) Respiration rate of the control increased until 12 hour, after that it decreased and kept constant. Respiration rate of the treated samples was similar to the control. Ethylene production of the control increased until 12 hour, after that it decreased and became scarcely. On the other hand the ethylene production of the treated samples was smaller than the control. These results suggested that air-exposure at low temperature retarded the deterioration of appearance of shredded cabbages and moreover ethylene production was slightly reduced, though effects of this treatment on chemical components and respiration rate in shredded cabbage were not distinct.

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Glycine-rich protein (GRP) which is known as structural protein of plant cell walls was investigated on the distribution in soybean seed coat and adjacent tissues because of high level of glycine content. Soybean seed coat and adjacent tissues were separated into three parts, palisade and hourglass layers, spongy parenchyma layer, and aleurone and endosperm layers. The glycine molar percentage, 37%, in aleurone and endosperm layers was higher than those in the other layers. Although GRP in aleurone and endosperm layers was scarcely extracted with both of alkali and acid solutions at 4°C, it was effectively extracted with hot water at higher temperature than 80°C. GRP fraction was separated by gel fltration on Sephadex G-100 offraction extracted with hot water. The fraction contained approximately 50% of glycine and 13% of serine. The estimated molecular weight of GRP was approximately 30kDa.

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The relation between the heating temperature and Jelly strength(J.S) of the gel made from fish meat pastes of 46 Walleye pollack frozen surimis (SA grade, FA grade and 2nd grade) was examined. It was found that J.S. of the gel increased once and subsequently decreased with the heating time at a temperature between 40°C and 90°C. The rate constant of the gel-disintegration (KG) was estimated from J.S. of the gel after being heated for 20 minutes, and KG of the gel which was different due to grade of surimi at a heating temperature below 60°C was arranged in the following order; 2nd grade >FA grade>SA grade. It was suggested that KG of the setting temperature could be used as one of the quality indexes of frozen surimi.

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Using a pilot-scale methane fermentor incorporating an ultrafiltration membrane separator, we studied on Shochu distillery wastewater treatment. In order to avoid inhibition by NH₄⁺, the fermentor was fed with diluted wastewater. When the membrane separator worked effectively, a high concentration of microorganisms in the fermentor was maintained and the performance of the fermentor was stable to obtain a digested gas yield from 0.4 to 0.6m³/kg-VS and a VA concentration of the efnuent from 1000 to 2000mg/l. However, when the filtration rate of the membrane (flux) did not correspond to the increase of the feeding rate, the membrane flushing was frequently conducted, which resulted in drainage of the fermented liquid in the separator's pipe lines. Consequently the concentration of microorganisms decreased and the methane fermentation process was inhibited by the accumulation of VA. On the other hand, it was shown that the NH₄⁺ concentration was maintained at ca. 2000mg/l to avoid NH₄⁺ inhibition by feeding diluted wastewater. As a result, this fermentor showed that the design value of the loading rates of VS was determined to be between 4.8 and 8.0kg-VS/m³·d for obtaining a high yield or production rate of gases and 2.5 and 4.8kg-VS/m³·d for a high VA removal ratio, respectively.

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Characteristics of the absorption at 2170nm, which is due to peptide bonds, were investigated using various proteins. The intensities of the absorption due to peptide bonds were different depending on the kinds of proteins examined. The absorption of bovine serum albumin at 2170nm decreased by reducing its disulfide (S-S) bonds. The absorption of poly-L-glutamic acid in the a-helix state at 2170nm was stronger than that in the random coil state. These results suggest that the secondary structures of proteins affect the absorption at 2170nm. The extent of contribution of the secondary structures to the absorption intensity was statistically predicted using 9 proteins which have different contents in secondary structures such as α-helix, β-sheet and random coil structures. It was found that the relative extent of the α-helix, β-sheet and random coil structures to the absorption at 2170nm was approximately 2:1:1.

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