Gas cell distribution (sudachi) of baked cereal products was determined with computer image analysis of a print with China ink (print method) of a cross section of the product and a photograph (photo method) of the cross section stained with China ink. For the"sudachi" of bread, a positive correlation was obtained between the number of gas cell counted manually and the number measured with Image Analyzer (print method). A positive correlation was also obtained between the number of gas cell determined with thephoto method and that determined with the print method. By the photo method, both the specific volume and the ratio of gas cell area to the whole area of the cross section correlated negatively with the number of gas cell. A positive correlation was found betweenthe specific volume and the ratio of gas cell area to the whole area of the cross section. For butter sponge cake, the number of gas cell correlated negatively with the specific volume. Positive correlations were obtained between the specific volume and the ratio of gas cellarea to the whole area of the cross section, and between the number of gas cell and Heywood diameter of gas cell. From these results, it is concluded that computerized image analysis is very available for the investigation of "sudachi" of baked cereal products because of its convenience of measuring procedure.

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Orange pigment was found in the cell of Lactobacillus plantarum L622 (strain L 622) isolated from fermented rice noodle "Khanom Jeen" .The optimum culture condition for pigment formation was incubation at 25°C and pH 7.0 with Na gluconate as carbon source and cystine and methionine as amino acid source. Very little amount of pigment was found in the cell culture with glucose as carbon source. Addition of antibiotics which inhibit the protein synthesis increased the pigment for mation. Pigment formation was related with the rate of growth but not with the amount of intracellular ATP. Pigment forming strain L. plantarum L622 and pigment nonforming strain L 622 CW were not differed in the physiological characteristics. The growh of strain L 622 was stimulated by the addition of cystine or methionine while L622 CW was not. The difference between the strain L622 and strain L622 CW was the pattern of plasmid DNA. Strain L622 retained 5 bands of plasmids, 49kbp. to 12.6kbp. But strain L622 CW had 11.5kbp plasmid instead of 12.6 kbp plasmid. It suggested the pigment production of L622 was related with the plasmid.

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A peptide mixture obtained from enzymatic hydrolysis of milk casein was concentrated by using a low rejection reverse osmosis membrane (LRO membrane, sulphonated polyether sulphone composite membrane, NaCl rejection: 50%). The effect of LRO treatment on the chemical composition and amino acid composition of the peptide mixture was investigated. All samples were concentrated to a CF (concentration factor) of 3 in a batch concentration mode (BC). Furthermore, the only one sample was diafiltrated to a WDR (water dilution ratio) of 3 in a constant volume diafiltration mode (DF). (1) In the BC mode, the ash content of retentate was concentrated more than the nitrogen content. On the other hand, in the (BC+DF) mode, the result was the reverse. (2) In the BC mode, the nitrogen and ash contents and °Bx of the retentate increased with operating pressure. (3) Free amino acids decreased remarkably in the (BC+DF) mode than in the BC mode. However, a small difference between the decreasing rate of the hydrophilic and hydrophobic free amino acids was recognized in both mode. (4) LRO treatment was proved to be effective in eliminating free amino acids, but ineffective in removing bitter peptides.

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It is well known that dietary vegetable proteins lower a level of plasma cholesterol more than animal proteins. The partial hydrolyzates of soybean protein have been shown to have possible hypocholesterolemic effects. In this study, hypocholesterolemic effects of partially hydrolyzed pork meat (PHPM) was examined in cholesterol-fed rats. The effects of pork meat and PHPM on plasma cholesterol, triglyceride, phospholipid, lipoproteins and free amino acids were determined. Plasma cholesterol decreased in rats fed PHPM, more than rats fed intact pork meat. Among the proteases examined, papain was most efficacious and plasma cholesterol became significantly lower by increasing the amount of protease. Rats fed an amino acid mixture prepared by acid hydrolysis did not show reduced level of cholesterol. Plasma free amino acid pattern of rats fed PHPM was similar to that fed soybean protein. PHPM thus apppears to exert a hypocholesterolemic effect depending on peptides in hydrolyzed pork meat. Based on the present results, it should be possible to prepare meat products having hypocholesterolemic effects.

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To estimate rheological changes in food processing, a method for measuring the speed of flowing materials was developed. Changes in electrical impedance at two points 2mm apart from each other in the same direction of a flow were continuously measured. A crosscorrelation function was calculated from signal intensities of impedance. The peak of cross correlation indicates the lag time taken by materials to move from one messuring point to the other. The speed of flowing materials can be calculated from the lag time. This speed is considered to reflect rheological properties of the materials, so the relationship between the speed of flow and viscosity was investigated. A commercial amylograph was used as a food processing machine and a measuring instrument of viscosity. Two electrodes to neasure electrical impedance, which simply consisted of two needles, were installed inside a rotating cup of the amylograph. Model samples with three diflerent levels of viscosity were prepared by mixing flour and water. The speed of flow and viscosity were measured at four step rotating speed. As results of these experiments, it became obvious that for the application of this method, an adequate data length for calculation of cross-correlation and a suitable location of measuring points must be chosen according to a flow-speed level of samples.

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Under the fixed heat flux condition of radiative heating, the effects of radiant characteristics of heaters on crust formation and coloring processes at surfaces of white bread and wheat flour batter have been evaluated using five heaters of different kinds. The radiative heat flux from the heater to the sample surface was maintained constant throughout the experiments to examine the combination effects of the wavelength characteristics of the heaters and the absorptivities of tested foods for radiant heat. Results showed that the crust formation and coloring rate were dependent on the wavelength characteristics of the heater used, and that the radiant heating with shorter wavelength led to a greater heat sink into the food samples forming the relatively wet crust layers compared with the dry layers formed by heating with longer wave. The coloring rates with the infrared heaters emitting the longer wave were faster than those by the shorter one because of the greater increasing rates of temperature at the food sample surfaces. These results confirmed that both crust formation and coloring rates at a heated food surface were mainly interpreted in terms of the variation of wavelength characteristics of radiant heaters.

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To elucidate the hypotensive effect of beni-koji, the interrelationship between this effect of beni-koji and mycelial weight was examined. Mycelial was estimated from the content of glucosamine in koji's cell wall. Male spontaneously hypertensive rats (SHR) were fed on one of the semipurified diets containing 1% sodium chloride with beni-kojis, of which glucosamine contents were different. High concentration of glucosamine had a tendency of stronger hypotensive effects. In another line of experiment, several beni-kojis containing same amounts of glucosamine fermented with different koji-material showed almost same hypotensive effects in SHR. These feeding experiments indicated that the hypotensive effect of beni-koji was almost in proportion to its glucosamine content. Heat-treatment at 90°C for 20 min had no effects on this activity of Beni-hoji, but enhanced hypocholesterolemic activity.

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Ume liquor is made from white liquor by standing with fresh fruits of Ume (Prunus mume Sieb. et Zucc.) and sucrose for about three months. During this time sucrose is completely hydrolyzed to glucose and fructose. In this paper, the presence of invertase in fruits of ume and its some properties were reported. The enzyme extracted from acetone powder of ume fruits hydrolyzed sucrose and had a pH optimum at 3.0. Its activity was almost lost during lh incubation above 70°C. The presence of 20% ethanol instabilized the enzyme activity above 40°C. Km was 4.0×10^-2M. In the presence of 20% ethanol Vmax was 60%, but Km did not change; ethanol behaved as a noncompetetive inhibitor. It was concluded, from these results, that the sucrose in ume liquor was hydrolyzed by the invertase.

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Effects of plastic films on quality stability of broccoli (Brassica oleacea var. italica) were investigated at ambient temperature. The broccolis packaged in perforated low density polyethylene (LDPE), 30μm LDPE, 60μm LDPE and 15μm high density polyethylene (HDPE) pouches were stored at 20°C for 7 days. The broccoli packaged in the perforated LDPE pouch caused yellowing after 3 days and the Hunter L. b/|a| value increased. In the LDPE (30 or 60μm in thickness) pouches, it caused off-flavors after 2 or 3 days storage, and the ethanol and acetaldehyde concentrations in these pouches markedly in creased. The broccoli which packaged in the HDPE pouch comparatively kept quality for 3 days, and kept high levels of both sugar and ascorbic acid contents. The carbon dioxide (CO₂) concentrations in the LDPE (30μm and 60μm) bags were 30% and 22%, respectively. The CO₂ concentration in the 15μm HDPE pouch was 10%. Oxygen permeability of a 15μm HDPE film was 14000ml/(m²·day·atom) and a water vapor transmission rate was 32g/(m²·day).

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The effects of commercial sugar esters of varying hydrophile-lipophile balances (HLB) on the baking properties of frozen dough were studied by test baking, gassing power, dough expansion and determination of tension of the surface membrane of doughs thawed after periods of storage in the frozen state. Loaf baked from a dough mixed with sugar ester (HLB 15) and thawed after fixed frozen storage exhibited better expansion and oven spring than did those from control dough or dough mixed with a suger ester with lower HLB. A suger ester with an HLB value of 15.0 was found to protect dough fron freeze damage in gassing power and dough expansion compared to those with lower HLB. It is suggested that these effects are the result of protecting yeast cells from freeze injury with their surface active properties and binding with wheat porteins to maintain extensibility and higher tension of the surface membrane, even after prolonged storage in the frozen state.

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The survival of yeast in frozen dough in several stages in the baking process up to 10 weeks of frozen storage and the rheological properties of thawed dough were determined to clarify the causes of bread deterioration during long storage. Torulaspora delbrueckii was used as a freeze tolerant yeast and Saccharomyces cereuisiae as a freeze sensitive yeast. The survival yeast counts were constant in several steps of the breadmaking process before baking in non-frozen and frozen dough with both types of yeasts. The frozen dough using T. delbrueckii retained constant survival yeast counts for 10 weeks, but there was a decrease in the fermentative ability per yeast cell during longer storage. With white bread dough using T. delbrueckii, the fermentative ability gradually decreased, and with sweet bread dough, it decreased quickly from 4 weeks on. The survival counts of yeast on S. cereuisiae were 30% for white bread dough after 1 week storage and 70% for sweet bread dough. The changes in the rheological properties started immediately after freezing and the adhesiveness of thawed dough increased with the length of the storage period in every case regardless of the survival ratio of yeast cells. The long storage of frozen dough with T. delbrueckii has a negative effect on the quality of bread and appliable storage period is under 3 weeks.

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A specific method for the determination of pectin using four enzymes, polygalacturonase, pectinesterase, glucuronolactone reductase and ascorbate oxidase, is described. The method was based on the determination of D-galacturonic acid produced during in the hydrolysis of pectin by the action of polygalacturonase and pectinesterase. D-Galacturonic acid was determined by measuring the decrease in the absorbance of NADPH at 340nm with the reaction of glucuronolactone reductase. L-Ascorbic acid in fruits and vegetables that inhibits the activity of glucuronolactone reductase was removed by the action of ascorbate oxidase. Linear relations between the activities of glucuronolactone reductase and concentrations of D-galacturonic acid and pectin were observed in the ranges of 0.039-0.31%(w/v)and 0.050-0.30%(w/v), respectively. A good agreement was recognized between the enzymatic method and a colorimetric method for water soluble pectin prepared from grape and tomato.The value obtained by the enzymatic method for grape juice without a pre-treatment procedure was 1.95 times higher than by Dische's carbazole reaction method For water soluble pectin derived from alcohol insoluble solids (AIS). The difference between them was comparable to the value obtained by the enzymaticmethod for the alcohol soluble fraction that was not recovered as AIS. This suggests that the present method enables us to estimate both pectin and there lated lower molecular weight compounds formed by the action of enzymes during maturing without any complicated pre-treatment procedure.

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We studied the changes in chitin and N-acetylglucosamine(GlcNAc)contents and activities of chitinase and β-N-acetylglucosaminidase(β-GlcNAcase)during the fruit-body development of Flammulina uelutipes (Enokitake) which is one of the important edible mushrooms in Japan. The strain used (IFO7777) formed a matured fruit-body in liquid culture in 25 days. The chitin components of the fungus were 1.0-1.5%in dry mycelia and 2.0-4.0% in dry fruit-bodies, though both components were lower than that of the other fungi of basidiomycotina. The former components linearly increased during the mycelial growth, but when the fruit-body formation began, the increase was considerably suppressed. On the other hand, the amounts of GlcNAc in the culture filtrate and mycelia suddenly decreased at the stage of rapid growth of the fruit-body. It is, therefore, suggested that GlcNAc as a substrate is supplied from them for the synthesis of chitin in the fruit-body. Chitinase activity in mycelia increased at the growing stage of vegetative mycelia, but it was suppressed with the beginning of rapid development of fruit-body. However its high activity continued until the maturation of the fruit-body. The activity in the culture filtrate continuously increased until the maturation of the fruit-body. β-GlcNAcase activity showed a diererent pattern from that of chitinase, that is, the β-GlcNAcase activity in the mycelia decreased with the growth of the fruit-body, whereas that in the culture filtrate increased with the growth. β-GlcNAcase prepared from both mycelia and culture filtrate were partially purified by isoelectrofocusing chromatography and their characteristics were investigated.

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