Comparison of Transparent Gels with Turbid Gels Prepared from Egg White: Creep Analysis of Gels

Egg white from which the precipitate occurring during dialysis against water had been removed gave a transparent gel on heating at lower salt concentrations and pH 3.54. The addition of NaCl or a shift of pH from 3.54 to 4.50 brought about the turbid gels. Creep analyses of these transparent and turbid gels were done using a four-element mechanical model. The instantaneous elastic modulus, E₀, Newtonian modulus, ηn and retarded viscoelastic moduli, E₁ and η₁ increased with NaCl up to 125 mM and then decreased with increase in NaCl concentration at pH 3.54. At 125 mM NaCl and pH 3.54, a translucent gel was obtained. E₀ and η₁ decreased with the temperature of the gel, while E₁ and η₁did not change depending of temperature.     

Mass Production Method for Rice Protein Isolate and Nutritional Evaluation

We developed a method for mass production of rice protein isolate (RPI) and evaluated its nutritional quality in rats. To obtain thick slurry, rice flour was mixed with a 0.6% Termamyl 120L-solution (1:2, w/v) at room temperature (～23°C). The slurry was heated at 97°C for 2 hr with stirring. Gelatinization and liquefaction occurred simultaneously. RPI obtained by filtration and washing with boiling water, was more than 90% pure protein (dry matter basis). It also contained 6.4% dietary fiber, 1.3% ash, and 1.1% carbohydrate. RPI diets (40–50%) allowed the maximum growth in rats comparable to that with 25% casein diet.     

Binding of Taurocholate by Pectin in the Presence of Calcium Ions

Binding of taurocholate by pectin was examined in vitro, using low-methoxyl pectin and calcium lactate. Water in calcium pectate gel was partially separated from the gel by filtration through a glass-filter. Taurocholate bound by pectin was calculated after measurement of taurocholate in the filtrate by the UV absorption method. The amount of taurocholate bound by pectin increased linearly with increase in pectin concentration but independent of time. One gram pectin bound a maximum of 6.0 μmole of taurocholate.     

Toxic Compounds Formed on Prolonged Heating of Citrinin under Watery Conditions

Citrinin was partially decomposed by heating under aqueous conditions at 90°C for > 10 min and a group of degraded compounds (Group I) was detected by TLC. At 100°C and 110°C, citrinin disappeared rapidly, and the cytotoxicity of the samples increased with prolonged heating. At 120°C, citrinin disappeared more rapidly while TLC spots of Group I compounds also diminished upon >20 min heating and a new group of compounds (Group II) appeared. Cytotoxicity decreased rapidly at > 120°C and was eliminated after 10 min at 130°C. Group I appeared to contain toxic compound(s) but Group II did not. Heating citrinin under conditions similar to cooking may cause formation of additional cytotoxic compounds.     

High surface area solids obtained by intercalation of iron oxide pillars in montmorillonite

When montmorillonite is dispersed in aqueous solutions of trinuclear acetato-hydroxo iron(III) nitrate, [Fe₃(OCOCH₃)₇OH]NO₃, the interlayer cations of the montmorillonite are exchanged with the partially hydrolyzed trinuclear acetato complex ions. On heating the exchanged complex ions are converted into iron oxide pillars which keep the silicate layers apart and form micropores between the layers. The resulting product has a basal spacing of 16.7 Å and a specific surface area of about 300 m²/g at 500°C. Adsorption isotherms for various vapors on the product have been measured.     

EFFECTS OF DIETARY PLANT CEREBROSIDE ON GENE EXPRESSION IN THE LARGE INTESTINE OF 1,2-DIMETHYLHYDRAZINE (DMH)-TREATED MICE DETERMINED BY DNA MICROARRAY ANALYSIS

The effects of dietary plant cerebroside on colon gene expression by DNA microarray analysis in 1,2-dimethylhydrazine (DMH)-treated mice were investigated. After 9 weeks of feeding with DMH, decreases and increases in the levels of expression of 110 and 145 genes were detected, respectively. Especially, the expression of Soggy-1, which suppresses the Wnt signaling pathway, was increased, while that of Ras-associated protein, which induces the mitogen-activated protein (MAP)-kinase pathway and is responsible for the development of aberrant crypt foci (ACF), was decreased. The results of the present study indicated that dietary cerebroside in DMH-treated mice regulates the Wnt signaling and MAP-kinase pathways, and prevents the development of ACF in the large intestine.

PRACTICAL APPLICATIONS

Dietary plant cerebroside increased expression of Soggy-1 mRNA, which suppresses the Wnt signaling pathway, and decreased expression ofRas-associated protein, which induces the MAP-kinase pathway in 1,2-dimethylhydrazine (DMH)-treated mice. The results of the present study indicated that dietary cerebroside in DMH-treated mice regulates the Wnt signaling and MAP-kinase pathways, and prevents the development of aberrant crypt foci in the large intestine, thus being of potential use for nutraceutical applications.     

Nature and Thermal Evolution of Amorphous Hvdrated Zirconium Oxide

The thermal behavior of amorphous hydrated zirconium oxide and its coprecipitates with other oxides was studied. Solid solution with a limit of solubility seems to exist in the amorphous coprecipitates. A relation with the high-temperature solid solution was established. The structure of the amorphous zirconia was studied by X-ray and neutron diffraction; a thin plate model related to the structure of tetragonal zirconia is proposed. Heating the precipitates in an oxygen-free atmosphere produced a black nonstoichiometric oxide and stabilization of the tetragonal form.     

Quality Evaluation of Fish Meat by 31 Phosphorus-Nuclear Magnetic Resonance

³¹Phosphorus-Nuclear Magnetic Resonance (³¹P-NMR) was used to evaluate degree of freshness of loach muscle depending on metabolic changes of high energy phosphate compounds. The phosphocreatine ([PCr])/inorganic phosphate ([Pi]) ratio was found to be a sensitive index of early metabolic hypofunction. Ratios of [PCr]/β-phosphate of ATP ([β-ATP]), and [Pi]/[β-ATP] were demonstrated to be appropriate indexes to estimate such metabolic changes in fresh fish. The intramuscular levels of creatine phosphate, ATP and pH were maintained at higher levels in blood-drained loach than in untreated fish. The freshness of fish which were bled and washed at lower temperatures were better preserved.     

A Proposal of Identifying Optimized Layout of Devices in Electromagnetic Resonant Coupling Type Wireless Power Transfer System

Recently, a system for wireless power transfer (WPT) using electromagnetic resonant coupling has been evaluated and developed for practical applications such as a wireless charge system for automobiles or electronic devices. However, the efficiency of an electromagnetic resonant coupling type WPT system with LC resonators is greatly affected by the layout of the LC resonators allocated in the system. This means that there is an optimum layout for the LC resonators for transferring wireless power at higher efficiency. This paper presents a new method for identifying the optimum layout for the LC resonators in a WPT system. One of the key ideas is that the problem of finding the optimum layout is replaced by the problem of calculating the equivalent current sources in the LC resonators. The amplitude of the equivalent current sources can be calculated to solve ill‐posed system equations by using inverse analysis. First, the proposed method is described. The system equations to be solved are formulated by means of equivalent circuit techniques. Second, the proposed method is applied to a simplified model to identify the optimum layout for the LC resonators in a WPT system. Then, the results found using the proposed method are verified by comparing the ratio of receiving power with the identified layout and without the LC resonator. Finally, in order to verify the validity of the proposed method, the calculated results are compared with the experiment results using the same model.     

High Precision On‐Line Offset Correction for Motor Angle Sensors

In this paper, an angle detecting system is proposed that calculates the offset correction values for the sine and cosine signals of angle sensors. The offset correction values are calculated not from the offset errors of the sine and cosine signals but from the 1f angle error (the fundamental frequency component of the sine and cosine signals) of the angle signals. Therefore, the system can correct the 1f angle error even when the sine and cosine signals contain the double‐frequency components of the sine and cosine signals, as well as the dc offset errors. Moreover, it is possible to use low‐cost microcomputers with low computing speed, because the offset correction values are dc quantities.