Composition of Peel Oil from Citrus Unshu

Constituents of aroma of peel oil (both oleoresin and cold-pressed oil) from Citrus Unshu were isolated by column chromatography and gas chromatography (GLC). and identified mostly by infrared (IR), partially by mass (MS) and nuclear magnetic resonance (NMR) spectroscopy.

One hundred and seven compounds were found in the oil and among them, four sesquiterpene hydrocarbons, five acetates, five carbonyls and five alcohols were identified as a main constituents which contributed to difference in flavor from other citrus peel oils. Characteristics of aroma of C. Unshu was discussed on the basis of quantitative analysis.     

Chemical Structures of New Piericidins Produced by Streptomyces pactum

Chemical structures of new piericidins produced by Streptomyces pactum are elucidated on the basis of mass, PMR and CMR spectral analyses. Consequently, these piericidins were shown to be constructed by a combination of variations in each four functionalities and carbon skeletons.     

Effects of the Storage in an Atomosphere of Carbon Dioxide on Ovomucin

The yolk index of newly laid egg was 0.50, while that of the egg stored at 30°C for 15 days in an atmosphere of carbon dioxide at a pressure of 2 kg/cm² and in air was 0.43 and 0.25, respectively.

The carbohydrate content of ovomucin gel (B) obtained from the eggs stored in an atmosphere of carbon dioxide was higher than that of ovomucin gel (B) obtained from the eggs stored in air.

The free boundary electrophoretic pattern of ovomucin gel (B) obtained from the eggs stored in an atmosphere of carbon dioxide consisted of two peaks, and the relative mobility of each peak showed the same value as that of the corresponding each peak of ovomucin gel (B) obtained from newly laid egg white.

The fractionation pattern obtained by density gradient column electrophoresis of ovomucin gel (B) obtained from the eggs stored in an atmosphere of carbon dioxide showed two peaks, peak-F and peak-S, while that of the eggs stored in air showed a considerable diminution in peak-F.

From these results, discussion was made about the occurrence and mechanism of egg white thinning when eggs were stored in an atmosphere of carbon dioxide.     

Volatile Components of Roasted Shrimp

The components of the strong and favorable aroma obtained from roasted shrimp were investigated. The aroma concentrate of roasted shrimp was isolated by combining the dichloromethane extract and carbon dioxide distillation methods. The concentrate was fractionated into acidic, basic and neutral fractions. Each fraction was analyzed by combined gas chromatography-mass spectrometry. Seventy-seven compounds were identified, among which isovaleric acid, alkyl pyrazines, isovaleramide, ketones and some sulfur-containing compounds were the main and characteristic constituents of the roasted shrimp aroma.

These constituents were compared with those of the volatiles of boiled shrimp, which was prepared by using simultaneous distillation and extraction methods in a modified Likens and Nickerson’s apparatus.     

Colorimetric Determination of Biphenyl in Citrus Fruits

Acylmonogalactosyldiglyceride (acyl-MGDG) was isolated from leaf homogenates of tobacco, and its structure was determined to be 1,2-di-O-acyl-3-O-(6-O-acyl-β-d-galactopyranosyl)-sn-glycerol by decomposition analyses, PMR, CMR and GC-MS. This compound had an identical structure with that found in disrupted spinach leaves, except for a significant difference in fatty acid composition. This compound was detected in disrupted leaves of tobacco but was not found in normal green, senescent and cured leaves. Monogalactosyldiglyceride and digalactosyldiglyceride decreased abruptly during incubation of leaf homogenates, which was accompanied by the rapid formation of acyl-MGDG.     

Synthesis and Toxicity of Allethrin-(Z)-metabolites

(±)-trans-Allethrin-(Z)-ol (IV), (±)-trans-allethrin-(Z)-al (V) and (±)-trans-allethrin-(Z)-acid (VI), the minor components of allethrin metabolites in the insect body, were synthesized. The toxicities of newly synthesized allethrin derivatives (IV, V, VI) and of (±)-trans-allethrin-(E)-acid (Xc) to houseflies (Musca domestica L.) were examined by the injection method. And their low toxicities seem to support the hypothesis that oxidation at the isobutenyl side chain of the acid moiety of the allethrin molecule is a detoxication process in the insect body.     

Simultaneous Determination of Patulin and Penicillic Acid in Grains by Gas Chromatographic Method

Changes in aggregation and properties of alkali-treated soybean 7S and 11S globulins depend upon protein concentration during alkali-treatment. Such variables were investigated by viscosity, electrophoresis, circular dichroism, pulsed NMR, emulsion capacity and CaCl₂ precipitation measurements. In lower protein concentrations, the intrinsic viscosity decreased and the penetrative fractions into electrophoresis gel increased. The reduced contacts of proteins during neutralization resulted in smaller aggregates. Also specific fractions which were more sensitive to protein concentration on aggregation were observed for 11S globulin. The quantity of bound water depended only on pH at 7% concentration treatment. When the gel was formed, the bound water of protein increased, e.g., 0.085 g and 0.135 g/g protein at pH 10.6 and 13.2 treatment, respectively, whereas at 1% treatment, bound water showed almost no pH dependence (about 0.13 g/g protein). Furthermore, proteins prepared at higher protein concentrations were characterized by higher emulsion capacity and CaCI₂ precipitation ability. However, no protein concentration dependence was seen in the secondary structure of the aggregates.     

Functional and Structural Properties of Ovomucin

Relationships between the structural (hydrophobicity and viscosity) and functional (foaming and emulsifying) properties of proteins were investigated by using a polymeric form of ovomucin (soluble type), and dissociated ovomucins which were treated with sonication (sonicated type) and reduction (reduced type). The soluble, sonicated and reduced ovomucins were ascertained to have excellent foaming and emulsifying properties. The foaming properties of the ovomucins decreased in proportion to decreases in the viscosity as the dissociation proceeded, in the order of the soluble, sonicated and reduced types. On the other hand, the emulsifying properties of ovomucins increased in proportion to increases in the surface hydrophobicity as the dissociation proceeded.

Thus, it was suggested that the foaming properties of ovomucins were dependent upon viscosity, and that the emulsifying properties of ovomucins were dependent upon surface hydrophobicity.     

Rate-adjusted cross-linking reaction by photoresponsive α-bromoaldehyde (PBA)-conjugated ODN

We developed a photoresponsive α-bromoaldehyde-conjugated oligonucleotide (PBA-ODN). The PBA-ODN selectively reacted and formed covalent bonds with target oligonucleotides having adenine or cytosine at the frontal position of the aldehyde derivative. Kinetic studies revealed that PBA-ODN has increased kinetic rates for the formation of cross-linked duplexes compared with the corresponding α-chloroaldehyde-conjugated oligonucleotide (PCA-ODN).