The effect of the concentration of soybean powder (11-17% (w/w)) on soybean curds prepared from powdered soybean in the presence of glucono-δ-lactone (GDL) were studied by rheological measurement (compression test and dynamic viscoelastic measurement), measurement of amount of syneresis, observation of the network structure by confocal laser scanning microscopy (CLSM) and sensory evaluation of physical properties. Results of rheological measurements of soybean curd indicated that the rupture strain, rupture stress, rupture energy, storage modulus and loss modulus increased with increasing concentration of soybean powder. In the protein concentration range of 4.4-6.9% (w/w), the storage modulus was proportional to 2.3 tH power of protein concentration. The degree of syneresis of this soybean curd decreased with increasing concentration of soybean powders. CLSM data indicate that the network structure of the curd increased concurrently with the concentration of soybean powder. The network structure of the curd was well correlated with the results obtained from rheological measurements. As sensory evaluation indicated that the soybean curd with a higher concentration of soybean powder (15% (w/w) or 17% (w/w)) was observed to be harder, less moist and fuller bodied, it was judged preferable to the soybean curd with lower concentration (11% (w/w)).

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The aim of this study was to produce fermented “Shishibishio” meat sauce from pork and analyze its properties. The fermentation mixtures (moromi) were prepared by mixing ground pork with salt at three different concentrations (15, 20 and 25% w/w) with koji, pepper, water and Alcalase 2.4L. The mixtures were then incubated at 30°C for 6 months. After one month of fermentation, Flavourzyme 500L was added to the moromi mixtures. Bacterial counts gradually decreased during fermentation, and after 6 months the common bacteria count was 3.9-7.0×10²cfu/g, lactic acid bacteria count was below 300, and coliform bacteria were undetected. The recovery percentage of Shishibishio obtained from moromi was between 67.0 and 78.5% with a pH value between 4.76 and 5.01 and protein recovery percentage between 71.9 and 79.8%. Total nitrogen, peptides and free amino acid contents were 1.7-2.0g, 3.5-6.3g and 4.8-7.8g per 100ml, respectively. The addition of Flavourzyme 500L increased the total free amino acid content to 12.2-16.5% (p<0.05). A 15% salt mixture resulted in a 20.5 to 20.8% salt concentration in the product, and 20 and 25% salt mixtures resulted in product salt concentrations of 22.8 and 23.5%, respectively. Results of the sensory evaluation of Shishibishio indicate that 20% salt moromi has a higher sensory evaluation value which is further increased by the addition of Flavourzyme 500L.

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Angiotensin I-converting enzyme (ACE) inhibitory activity in surimi fermented with lactic acid bacteria (LAB) was investigated to facilitate improvements in surimi fish sausage. Arabesque greenling surimi, Besugo surimi, Alaska Pollack surimi and a mixed surimi were fermented with Lactobacillus delbrueckii subsp. lactis 306701 to evaluate the effect of ACE inhibitory activities. High ACE inhibitory activity (90.0%) was observed in Arabesque greenling surimi and no ACE inhibitory activity was found in Alaska Pollack surimi. A salt-soluble protein (SSP) solution of Arabesque greenling surimi was tested and the influences of fermentation temperatures and times on ACE inhibitory activity were also examined using 16 LAB strains. The resulting ACE inhibitory activity of fermented SSP solutions differed. Pediococcus acidilactici ID7 (inhibitory activity, 47.6%) and Lactobacillus plantarum 6214 (inhibitory activity, 40.6%) displayed higher ACE inhibitory activity. The ACE inhibitory activity and amino compound quantity in fermented Arabesque greenling surimi were also investigated, and ACE inhibitory activity appeared to be induced by amino compounds degraded by inoculated LAB and indigenous bacteria.

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The effects of Bunashimeji mushroom (Hypsizigus marmoreus) on serum and hepatic lipid levels were investigated in C57BL/6J mice. The experimental diets were prepared by adding 10% (w/w) Bunashimeji powder to a control diet containing 20% fat and 0.5% cholesterol given ad libitum to male C57BL/6J mice for 6 weeks. Body weight and food intake were recorded every 2 days, and serum and liver levels of triacylglycerols (TG), total cholesterol (TC), and phospholipids (PL) were analyzed at the end of the feeding period. No significant differences were observed in food intake and body weight gains between the control and Bunashimeji groups. Results also indicated that the weight of liver, perirenal and epididymal adipose tissues in the Bunashimeji group was significantly lower than in the control group (p<0.05). Liver triacylglycerols were significantly lower in the mice fed the Bunashimeji diet than in mice fed the control diet. The serum cholesterol level of the Bunashimeji group was also significantly lower than that of the control group (p<0.05). mRNA abundances of acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS), a key enzyme of fatty acid synthesis, were significantly higher in the Bunashimeji group than the control group. Although the mechanism for this mRNA expression has not been fully characterized, these results suggest that Bunashimeji suppresses hepatic triacylglycerols accumulation and lowers blood cholesterol levels.

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The size of bubbles and degree of fat globule aggregation in cream have been reported to influence the shape retention ability of whipped cream. Shape retention ability also changes when whipped cream is stored. In order to investigate bubble size and fat globule aggregation, fresh cream with 45% (w/w) fat was whipped to stiffness at different speeds (140, 180 or 200rpm). Differences in resistivity against deformation during storage were found in whipped cream prepared at different whipping speeds. It appears that the degree of fat globule aggregatation and overrun of the whipped cream influenced resistivity against deformation. Furthermore, higher correlation was found between the overrun and the continuous phase viscosity of the sample whipped at 140rpm, and between the average bubble size and the degree of fat globules aggregation of the sample prepared at 200rpm. The present results suggest that the degree of fat globule aggregation in the continuous phase influence the shape retention ability of cream whipped at 140rpm, and that the presence of aggregates of fat globules on the surface of bubbles influence the shape retention ability of the cream whipped at 200rpm.

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This study investigated the angiotensin I converting enzyme (ACE) inhibitory activity and the anti-hypertensive effect of Enzyme-Modified Cheese (EMC). EMC was synthesized from the hydrolysis of Danish skim milk cheese with the combination of commercial protease, endo-type protease, and exo-type protease. EMC-No. 9 made with Protease N amano, Umamizyme, and Flavourzyme showed the highest ACE inhibitory effect (IC₅₀=36.3μg/ml). Single oral administration of EMC-No. 9 (100, 500 and 100mg/kg) dose-dependently and significantly lowered the systolic blood pressure in spontaneously hypertensive rats for up to 8 hours. Thus, EMC-No. 9 could be useful for the treatment of hypertension.

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The quality of a new surimi-based product (healthy kamaboko) prepared from fish sauce, katsuobushi-kelp extract and yeast extract was compared with that of a commercial control product with chemical condiments, which is commonly eaten in Toyama district. Sensory evaluation revealed that the toughness, elasticity and agreeable fish flavor of the new product were superior to those of the control product, although the external appearance of the new product was judged inferior to that of the control. No difference was found in umami taste strength. Results indicated the following : 1. The values of breaking strength and breaking strain of the new product were slightly higher than those of the control. 2. The free amino acid content, particularly for glutamic acid and glycine, was lower in the new product than in the control. 3. The amount of inosine 5′-monophosphate was lower in the new product than in the control, but adenosine 5′-monophosphate and guanosine 5′-monophosphate were higher in the new product than in the control. These nucleotides were thought to provide sufficient umami taste by synergistic taste effects with glutamic acid. Additionally, the new product contained volatile components found in fish sauce and did not contain the sorbic acid and 2-methylthiophene that was found in the control product. The new product could be stored for 40 days at 5°C without any bacterial proliferation while the control product contained sorbic acid as a preservative.

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Pectin esterase (PE) is a key enzyme for the cloud stability of citrus juice. We found that PE was inactivated by the application of the newly developed high electric field AC (HEF) treatment at 75°C for 0.63sec, which is much shorter than microwave treatment and water-bath heating treatment. HEF treatment inhibits lemon pulp aggregation and maintains lemon juice cloud stability.
Our findings suggest that PE inactivation was not caused by a superimposed electric field, but by rapid heating in 0.05sec of the HEF treatment. Furthermore, this significant rise in temperature allows decreasing the holding time by 0.58sec. Additionally, the heat treatment induced less denaturation of citrus juice components. Therefore, high-quality citrus juice is obtained by PE inactivation with HEF treatment.

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The polysaccharide of Hsian-tsao (HTP), Mesona procumbens Hemsl., does not itself form a gel, but induces gel formation in the presence of added starch, although the mechanism is still unclear. To understand the effect of a HTP on gel formation, we investigated its constituent sugars by methylation analysis. HTP was found to consist of rhamnose, arabinose, xylose, mannose, glucose, galactose, and galacturonic acid. Although methylation may not have proceeded to completion, rhamnose was found as 2-O-, 3-O-, and 4-O-methyl derivatives. Incomplete methylation suggests that HTP has a compact conformation of high heterogeneity.

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[in Japanese]

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