Changes in Some Properties of Starch Granules of Maize Having Amylose-extender Gene by Amylase Attack

Properties of residual starch by glucoamylase attack were investigated in starch granules of maize (Zea mays L.) of amylose-extender (ae) type (commercial “High Amylose-7”; HA-7). As increasing extent of hydrolysis, the amylose and amylopectin fractions decreased and low-molecular-weight materials were accumulated. Decrease in absorption intensity and sift to a range of shorter wavelength in γmax. of absorption spectra of iodine-starch complexes were observed. The minified fractions had a peak of about 22 average glucose-units and were nearly linear chains. It was suggested that the minified materials consisted of portion resisted to amylases in starch granules according to hydrolysis curves by glucoamylase. The fractions concerned to crystalline area of ae starch were suggested from X-ray diffraction patterns.     

Inter-laboratory study for validation of a Japanese official analytical method for determination of patulin in apple juice

To validate a modified version of AOAC official method of analysis 995.10 as an official standard in Japan for determination of patulin in apple juice, an inter-laboratory study was performed in 11 laboratories using a non-contaminated sample, 2 naturally contaminated samples and 2 spiked samples of apple juice. For naturally contaminated apple juices, the relative standard deviations for repeatability and reproducibility were 3.2, 7.1% and 10.0, 21.7%, respectively. HORRAT values were 0.4, 0.9. The average recovery of patulin from spiked sample was 83.7%. The limit of quantification was calculated as 10 microg/kg. From these results, the method was thought to be suitable as an official standard for determination of patulin in apple juice in Japan.     

Simultaneous determination of 7 kinds of preservatives and saccharin in foods with HPLC, and identification with LC/MS/MS

A simultaneous determination method of saccharin (SA), sorbic acid (SOA), benzoic acid (BA), p-hydroxybenzoic acid ethyl (PHBA-Et), p-hydroxybenzoic acid isopropyl (PHBA-isoPr), p-hydroxybenzoic acid propyl (PHBA-Pr), p-hydroxybenzoic acid isobutyl (PHBA-isoBu) and p-hydroxybenzoic acid butyl (PHBA-Bu) in foods by HPLC was examined. A mixture of acetonitrile-water (1:1) was used to extract these additives from foods excluding liquid foods, while acetonitrile was used to extract them from liquid foods. HPLC was performed using a TSKgel ODS80Ts (4.6 mm i.d. x 150 mm) column with a mobile phase of 0.01% formic acid solution containing 2 mmol/L-di-n-butyl (or amyl) ammonium acetate (A) and acetonitrile (B) under the following conditions: A/B = 8: 2 (0-8 min) --> 6: 4 (15-32 min). Recoveries of these additives spiked in foods were 78-120%. The determination limits were 10 microg/g. As the identification method, examination by liquid chromatography with electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) was used. Unknown compounds were identified by detection of product ions from their precursor ions in the negative mode with multiple reaction monitoring, m/z 182 > 106 for SA, m/z 121 > 77 for BA, m/z 111 > 67 for SOA and m/z 165 > 92 for PHBA-Et. Ratios of intensity of m/z 179 > 137 to m/z 179 > 92 were used for identification of isomers PHBA-isoPr and PHBA-Pr, and the ratios of intensity of m/z 193 > 137 to m/z 193 > 92 were used for isomers PHBA-isoBu and PHBA-Bu, because these isomers have very similar (Received December 12, 2006)     

Characterization of miRNAs in Milk Small Extracellular Vesicles from Enzootic Bovine Leukosis Cattle

Enzootic bovine leukosis (EBL) is a B-cell lymphosarcoma caused by the bovine leukemia virus (BLV). Most BLV-infected cattle show no clinical signs and only some develop EBL. The pathogenesis of EBL remains unclear and there are no methods for predicting EBL before its onset. Previously, it was reported that miRNA profiles in milk small extracellular vesicles (sEVs) were affected in cattle in the late stage of BLV infection. It raised a possibility that miRNA profile in milk sEVs from EBL cattle could be also affected. To characterize the difference in milk of EBL cattle and healthy cattle, we examined the miRNA profiles in milk sEVs from four EBL and BLV-uninfected cattle each using microarray analysis. Among the detected miRNAs, three miRNAs—bta-miR-1246, hsa-miR-1290, and hsa-miR-424-5p—which were detectable using quantitative real-time PCR (qPCR) and are associated with cancers in humans—were selected as biomarker candidates for EBL. To evaluate the utility of these miRNAs as biomarkers for EBL, their levels were measured using milk that was freshly collected from 13 EBL and seven BLV-uninfected cattle. bta-miR-1246 and hsa-miR-424-5p, but not hsa-miR-1290, were detected using qPCR and their levels in milk sEVs from EBL cattle were significantly higher than those in BLV-uninfected cattle. bta-miR-1246 and hsa-miR-424-5p in sEVs may promote metastasis by targeting tumor suppressor genes, resulting in increased amounts in milk sEVs in EBL cattle. These results suggest that bta-miR-1246 and hsa-miR-424-5p levels in milk sEVs could serve as biomarkers for EBL.     

Thermal and magnetic properties of copper potassium tutton salt below 0.15 K

The specific heat and the ac susceptibility of copper potassium tutton salt have been measured between 0.01 and 0.15 K. The magnetic phase transition from the paramagnetic to the canted ferromagnetic state was observed at 29.5 mK in zero field. From the obtained electronic entropy curve this salt is considered to be a Heisenberg-type ferromagnet. The copper nuclear specific heat of the hyperfine splitting is estimated to beC _N =1.1×10^–5 R/ (T ²/[K²]), which is one order smaller than the value calculated from previous results of the paramagnetic resonance.     

The self-assembled monolayer of saccharide via click chemistry: Formation and protein recognition

We prepared the saccharide-immobilized substrate via click chemistry. The azide-terminated saccharides were reacted by a facile metathesis reaction. The density of saccharides was controlled by the incubation time of SAM preparation. The saccharide-protein interaction was analyzed using the saccharide substrate. The interaction of the saccharide substrate with protein was strong and specific due to the glyco-cluster effects. The interaction with amyloid β was analyzed by the monosaccharide-immobilized substrate, and the sulfonated saccharides showed strong interaction.     

Mycological examination of domestic unpolished rice and mycotoxin production by isolated Penicillium islandicum

Fungi growing on domestic rice were examined from April to June, 2003. One hundred samples of rice, which had been harvested in the autumn of 2002, were collected from the local market, and 15 samples of stored rice, which had been harvested in 2001 and stored in warehouses under government control, were used as samples. From each sample, 50 grains (100 grains in total) were plated on potato-dextrose agar (PDA) and malt yeast 40% sucrose agar (M40YA) containing chloramphenicol after being washed with sterile distilled water to remove any microorganisms on the surface, and incubated at 25 degrees C for a week. For most of the rice samples harvested in the preceding year, the proportion of grains infected with fungi was less than 20% of the total grains tested. In about half the samples of rice stored for one and half years, more than 80% of the grains were infected with fungi that grew on M40YA. The major genera of fungi isolated from the rice harvested in the preceding year were Penicillium and Alternaria, and those from the rice stored for one and a half years were Aspergillus, Penicillium and Eurotium. P. islandicum, A. versicolor, A. ochraceus and others were isolated as possible mycotoxin-producers in the mycoflora of domestic rice. P. islandicum was isolated from 3 samples, and 82% of the grains were infected with this fungus in one sample. All three isolates from these samples appeared to produce luteoskyrin on Czapek yeast extract agar, based on TLC and HPLC analysis.     

A simple combinatorial method to discover Co-Mo binary catalysts that grow vertically aligned single-walled carbon nanotubes

A simple yet versatile combinatorial method to discover binary metal nanoparticle catalysts was developed. In this method, the nominal thickness of component metals can be independently screened for a wide range by simply setting a mask with a slit above a substrate during sputter-deposition. Using this method, we prepared a catalyst library with Mo (0.2-4 nm) and Co (0.2-8 nm) thickness profiles on a SiO₂/Si wafer and discovered active catalysts that grow vertically aligned single-walled carbon nanotubes by alcohol catalytic chemical vapor deposition.     

Effects of membrane charges and hydroperoxides on Fe(II)-supported lipid peroxidation in liposomes

The processes in producing a lag phase in Fe²⁺-supported lipid peroxidation in liposomes were investigated. Incorporation of phosphatidylserine (PS) or dicetyl phosphate (DCP) into phosphatidylcholine [PC(A)] liposomes, which have arachidonic acid, produced a marked lag phase in Fe²⁺-supported peroxidation, where PS was more effective than DCP. Phosphatidylcholine dipalmitoyl [PC(DP)] with a net-neutral charge was still effective in producing a lag phase, though weak. Increasing concentrations of PS, DCP, and PC(DP) prolonged the lag period. Initially after adding Fe²⁺, slight oxygen consumption occurred in PC(A)/PS liposomes including hydroperoxides, followed by a lag phase. An increase in the hydroperoxide resulted in a shortening of the lag period. The initial events of Fe²⁺ oxidation accompanied by oxygen consumption were dependent on the hydroperoxide content, but significant changes in diene conjugation and hydroperoxide levels at this stage were not found. The molar ratios of both dis-appeared Fe²⁺ and consumed O₂ to preformed hydroperoxide in liposomes with or withouttert-butylhydroxytoluene were constant, regardless of the different amounts of lipid hydroper-oxides. The antioxidant completely inhibited the propagation of lipid peroxidation in the lipid phase, following a lag phase. In a model system containing 2,2′-azobis (2-amidinopropane) dihydrochloride, Fe²⁺ were consumed. We suggest that Fe²⁺ retained at a high level on membrane surfaces play a role in producing a lag phase following the terminating behavior of a sequence of free radical reactions initiated by hydroperoxide decompositin, probably by intercepting peroxyl radicals.     

Electroantennogram responses of grape borerXylotrechus pyrrhoderus bates (Coleoptera: Cerambycidae) to its male sex pheromone components

Electroantennograms were recorded from the grape borerXylotrechus pyrrhoderus in response to serial dilutions of male sex pheromone components, (2S,3S)-octanediol and (2S)-hydroxy-3-octanone, and to 100 g of their optical isomers and host plant substances. Female antennae always responded more strongly than male antennae. Antennae of both sexes were highly sensitive to (2S)-hydroxy-3-octanone. F/M ratio (female to male EAG value) was greater for male sex pheromone components, especially (2S,3S)-octanediol, and their optical isomers than plant substances. Antennal sensitivity to optical isomers (2R,3R-octanediol and 2S,3R-octanediol) was lower than true pheromone components.