Oxygen-dependent Oxidation of Formaldehyde by Cell-free Extract of a Methanol-utilizing Yeast,Candida sp.

The purpose of this study was to investigate the effects of soy germ protein intake on body composition. Wistar rats were fed experimental diets for 16 weeks. These consisted of soy germ protein, soy protein, or casein. Abdominal adipose tissue weights significantly lower and hindlimb muscle weights were significantly higher in the soy germ protein group than in the casein group.     

Effeet of Metal Ions on Activity of Exopectic Acid Transeliminase of Erwinia sp.

Contrary to the exopectic acid transeliminase of Clostridium multifermentans, that of Erwinia sp. was activated strongly by Na⁺ and to a much less extent by Ca²⁺. K⁺ had a small stimulating effect on the enzyme activity. Mn²⁺ and Co²⁺, like Ca²⁺, activated the enzyme weakly. Ba²⁺ and Mg²⁺ showed no and a slight inhibitory effect, respectively, on the activity.

An almost total loss of activity was caused by the addition of EDTA to the reaction mixture. In the presence of Na⁺ the enzyme activity was restored by addition of divalent cations. Individual monovalent cations or each of the divalent cations was ineffective in restoring the activity.     

Genotyping of a Miso and Soy Sauce Fermentation Yeast,Zygosaccharomyces rouxii,Based on Sequence Analysis of the Partial 26S Ribosomal RNA Gene and Two Internal Transcribed Spacers

We analyzed sequences of the D1D2 domain of the 26S ribosomal RNA gene (26S rDNA sequence), the internal transcribed spacer 1, the 5.8S ribosomal RNA gene, and the internal transcribed spacer 2 (the ITS sequence) from 46 strains of miso and soy sauce fermentation yeast, Zygosaccharomyces rouxii and a closely related species, Z. mellis, for typing. Based on the 26S rDNA sequence analysis, the Z. rouxii strains were of two types, and the extent of sequence divergence between them was 2.6%. Based on the ITS sequence analysis, they were divided into seven types (I–VII). Between the type strain (type I) and type VI, in particular, a 12% difference was detected. The occurrence of these nine genotypes with a divergence of more than 1% in these two sequences suggests that Z. rouxii is a species complex including novel species and hybrids. Z. mellis strains were of two types (type α and type β) based on the ITS sequence. Z. rouxii could clearly be distinguished from Z. mellis by 26S rDNA and ITS sequence analyses, but not by the 16% NaCl tolerance, when used as the sole key characteristic for differentiation between the two species.     

Combined Effects of Dietary Protein Type and Fat Level on the Body Fat-Reducing Activity of Conjugated Linoleic Acid (CLA) in Rats

The interaction of dietary protein type and fat level on the body fat-reducing activity of conjugated linoleic acid (CLA) was studied in male rats fed diets containing casein (CAS) or soy protein (SOY) as a protein source with low fat (LF, 6.0% soybean oil) or high fat (HF, 13.0% soybean oil) combinations for 4 weeks. CLA was added at the 1.0% level to all diets. The weight of perirenal adipose tissue tended to be lower in the SOY groups than in the corresponding CAS groups, and the difference between the LF diets was significant. The weight of epididymal adipose tissue showed a similar but insignificant trend. The weight of brown adipose tissue was heaviest on the SOY-HF diet and lowest on two CAS diets, the SOY-LF diet being intermediate. The concentration of serum leptin was lowest on the SOY-LF diet and was significantly lower than that of the corresponding CAS group, but this difference disappeared when the dietary fat level increased. The serum cholesterol-lowering activity of SOY in relation to CAS was reproduced even when CLA was given. Thus the body fat-reducing activity of CLA was most marked when rats were fed the SOY-LF diet. Although the CAS-HF diet increased body fat deposition, the magnitude of the reduction by lowering dietary fat level was more marked than in the case of SOY. These results indicate a complicated interaction of dietary manipulations with the body fat-reducing effect of CLA, but the combination of CLA with the SOY-LF diet appears to be an appropriate approach.     

Lactones Produced through Thermal Oxidation of Higher Fatty Acids

Inhibitors of plant virus infection with systemic effects were found in the culture filtrates of Basidiomycetes such as Fomes fomentarius and Schizophyllum commune. These inhibitors were widely distributed in Agaricales and Polyporales. The inhibitors designated as BAS (Basidiomycete Antiviral Substance) were highly active against the mechanical transmission of tobacco mosaic virus (TMV). No toxic effect was observed on the host plants. BAS-F, a polysaccharide produced by F. fomentarius, almost completely inhibited infection, when BAS-F at 2 μg/ml was applied to the same surface of leaves of Xanthi-nc tobacco 24 h before TMV inoculation to the upper surface of the leaves, and 500/0 inhibition was shown when BAS-F at 10 μg/ml was applied to the under surface of leaves. BAS-F also induced systemic resistance to the non-treated leaves when it was applied to only one leaf of the plant. BAS-F also had similar effects against the infection of TMV on bell pepper and tomato plants.     

Soymorphins,Novel μ Opioid Peptides Derived from Soy β-Conglycinin β-Subunit,Have Anxiolytic Activities

Based on the amino acid sequence YPFV found in the soy β-conglycinin β-subunit, which is common to an opioid peptide human β-casomorphin-4, peptides YPFVV, YPFVVN, and YPFVVNA were synthesized according to their primary structure. On guinea pig ileum (GPI) assay, they showed opioid activity (IC₅₀ = 6.0, 9.2 and 13 μM respectively) more potent than human β-casomorphins, and were named soymorphins-5, -6, and -7, respectively. Their opioid activities on mouse vas deferens (MVD) assay were less potent than on GPI assay, suggesting that they are selective for the μ opioid receptor. Human β-casomorphin-4 and soymorphin-5 were released from the soy 7S fraction (β-conglycinin) by the action of gastrointestinal proteases. Soymorphins-5, -6, and -7 had anxiolytic activities after oral administration at doses of 10–30 mg/kg in the elevated plus-maze test in mice.     

Cloth-based hybridization array system for detection of transgenic soy and corn by multiplex polymerase chain reaction

A cloth-based hybridization array system (CHAS) was developed for detection of amplicons generated in a multiplex PCR targeting transgenic 35S and NOS sequences, as well as corn invertase and soy lectin genes. The CHAS provided confirmation of each amplicon on the basis of hybridization with specific capture probes, and enabled ease of discrimination of the multiplex PCR products by visualization of the amplicons on the array.     

Metabolism of isoflavones in human subjects

Isoflavones form a group of plant compounds that occur mainly in legumes, soy being the most important source in human diet. The high levels of isoflavones in the diet have been associated with a lowered risk for hormone-dependent diseases, including breast and prostate cancers, osteoporosis and cardiovascular disease. The metabolism of isoflavones in humans has been studied to a certain extent, but detailed studies are lacking. This paper reviews the current knowledge on metabolism of isoflavones and presents some preliminary results of a comprehensive soy feeding study, in which the phase I metabolites of soy isoflavones, daidzein, genistein and glycitein, were identified by GC-MS. This revised version was published online in June 2006 with corrections to the Cover Date.     

Coagulation and rheological behaviors of soy milk colloidal dispersions

Coagulation and rheological behaviors of soy milk are reviewed from the viewpoint of colloidal dispersion system. From the results of relative viscosity in the range of small oil body volume fractions, oil bodies containing oleosin behave as rigid spheres. The Krieger–Dougherty equation was found to describe relative viscosities well under high oil body volume fraction. These results indicate that oil bodies in soy milk behave as though suspended matter. Cross-linking between colloid particles occurs when the coagulant is added, and bulky clusters are formed. The viscosity rises due to the hydrodynamic effects of these bulky clusters. A new viscosity equation that combines the Krieger–Dougherty equation and the effective volume fraction could describe the viscos behavior well for wide range of solid contents. Tofu is made by adding a coagulant to soy milk. For lipid concentrations of less than 2%, rupture stress increases depending on the lipid concentration, whereas at concentrations of more than 3%, rupture stress tends to decline. Kinugoshi tofu samples have a maximum value for rupture stress depending on lipid concentration. Digestion of oleosin in high-fat soy milk using papain treatment results in the centrifugal separation of soy milk cream easily. This result indicates that oleosin let oil bodies in soy milk stable. Therefore, it is important to control the state of soy milk colloidal dispersions.     

近红外光谱技术快速检测原料乳中掺杂物

采用近红外光谱技术结合化学计量学方法,对原料乳中常见的2种掺杂物——大豆分离蛋白与植脂末进行定量分析研究。先通过不同光谱预处理方法结合偏最小二乘法（PLS）建模评价不同预处理方法的效果,结果表明通过平滑处理结合多元散射校正（MSC）进行光谱预处理效果最佳,大豆分离蛋白PLS定量模型相关系数（R2）与交叉验证均方差（RMSECV）分别为0.980 9、0.127 5,植脂末PLS模型分别为0.972 2、0.130 8。随后比较了不同建模方法的效果,结果发现：采用径向基神经网络（RBF）对大豆分离蛋白的建模效果最佳,R2为0.999 4,测试集均方根误差为0.003 1;采用广义回归神经网络（GRNN）方法对植脂末建模效果最佳,R2为0.998 9,测试集均方根误差为0.004 5。因此,合理结合近红外光谱技术与化学计量学方法可快速、准确检测原料乳中大豆分离蛋白和植脂末这2种掺杂物含量。