Fukuoka Industrial Technology Center

Anisakis is a parasite that is found in many marine products and can cause anisakiasis when present in fish consumed raw. The most common way to prevent anisakiasis is to freeze the fish, but this causes a noticeable decrease in the quality of the fish when eaten as sashimi. Although no practical method of killing anisakis other than freezing has been found, we have now succeeded in inactivating anisakis inside the fish meat by repeatedly and instantaneously applying electric current to the fish meat using pulsed power technology. The fish meat was placed in buffer saltwater, and pulsed power was applied multiple times. The immobilization rate was highest when the buffer saltwater was 5 mS/cm. The immobility ratio increased as the number of shots increased. Sensory evaluation of the fish meat after the pulse treatment confirmed that it retained its quality as sashimi. Breaking tests and color measurements were also conducted. We believe that this pulsed power treatment is a useful alternative to freezing as a method for killing anisakis.

Introduction: Collagenase plays an important role in the degradation of dermal matrix proteins leading to wrinkle formation. The objectives of this study were to evaluate the inhibitory effect of water-pepper (Polygonum hydropiper L.) sprout extract on the activity of collagenase and to identify the inhibitory compounds.Methods: Collagenase inhibitory activity was measured by spectrophotometric assay. Activity-guided fractionation was performed using liquid-liquid extraction of water and n-butanol and Diaion HP-20 column chromatography, followed by high-performance liquid chromatography (HPLC) fraction collection.Results: A methanolic extract of water-pepper sprout inhibited collagenase activity in a concentration-dependent manner with an IC50 value of 156.7 μg/mL. Collagenase inhibitory activity (IC50 = 23.5 μg/mL) was found in 50% methanol eluate from the HP-20 column chromatography of the n-butanol soluble fraction. The active compound (IC50 = 1.9 μg/mL) in the eluate was isolated by HPLC and identified as quercetin-3-O-galactoside (hyperoside) from comparing retention time, UV-Vis absorption, and mass spectra with those of the standard. Lineweaver-Burk plots revealed that hyperoside was an uncompetitive inhibitor against collagenase. Hyperoside was also the most abundant flavonoid present in the methanolic extract.Conclusion: These results suggest that water-pepper sprouts could be beneficial as a natural source of collagenase inhibitor which might be used for the treatment of skin aging.

We have been developing quick and simple system for detecting food-poisoning bacteria using a combination of an asymmetric PCR and a portable surface plasmon resonance (SPR) sensor. The system would be suitable for point-of-care detection of food-poisoning bacteria in the field of food industry. In this study, we established a novel method for quantifying the amplified forward (F) and reverse (R) chains of Staphylococcus aureus separately by high-performance liquid chromatography (HPLC). The concentration of single-stranded DNA amplicon excessively amplified, which is crucial for the system, could be calculated as the difference between those of the F- and R-chains. For the R-chain, a correction based on the F-chain concentration in the sample was used to obtain a more accurate value, because the determination of the R-chain concentration was affected by that of the coexisting F-chain. The concentration values were also determined by fluorescence imaging for electrophoresis gels of amplicons with FITC- or Cy5-conjugated primers, and they were in good agreement with the values by the HPLC. The measured concentration of the single-strand F-chain correlated well with the value of the SPR response against the probe that was a complementary sequence of the F-chain, immobilized on the sensor chip of the SPR sensor.

The phosphating of Mg alloy was performed in unagitated solutions containing 1 g·dm−3 of Mg, Ca, Sr, and Ba as alkaline earth metals (M) and 50 g·dm−3 of H3PO4 of pH 3 at 40℃ for 3 min. The structure and formation behavior of the phosphate films were investigated. The X-ray diffraction patterns of phosphate films broadened irrespective of the type of alkaline earth metal, which was a characteristic of an amorphous structure. XPS analysis revealed that the valence of P in the phosphate films was pentavalent. The pH in the vicinity of the Mg alloy during the phosphating, as measured using an Sb microelectrode, was approximately 10.4, 11.4, 10.7, and 12.0 in the solutions containing Mg, Ca, Sr, and Ba, respectively. This shows that phosphoric acid dissociates to the third stage during the phosphating, and the phosphate films comprising M3(PO4)2 containing an alkaline earth metal are formed. The phosphating was successively performed in two types of solutions containing different alkaline earth metals, and the cross section was analyzed. As a result, it was determined that the new phosphate films were formed at the interface between the Mg alloy substrate and phosphate films, and the previously formed phosphate films were boosted in the films.

An investigation on the improvement in hysteresis properties of high purity Fe-4 wt% Si prepared by cold crucible levitation melting was presented compared with a Fe-0.1 wt% C- 4 wt% Si alloy formed by the identical process. The results showed that thin elongated carbon compounds were precipitated in both grains and grain boundaries of Fe-0.1 wt% C- 4 wt% Si sample observed by means of Kerr effect microscopy and STEM, leading to an apparent degradation in coercivity, permeability and hysteresis loss. With regard to hysteresis loss in Fe-4 wt% Si, it increases linearly with the increase of maximum magnetic flux density below 1.4 T, whereas for Fe-0.1 wt% C- 4 wt% Si, it behaves nonlinearly even at low maximum magnetic flux density and rises sharply with the increase of maximum magnetic flux density. Additionally, the precipitated carbon compounds in the grain boundaries change the morphology of the grain boundaries.

We report an energy harvesting damper composed of a composite of piezoelectric polyvinylidene fluoride film and silicone rubber for applications in offshore structures. We describe the generation efficiency of sandwiched and coiled sheet geometries. Piezoelectricity was generated by cyclic compressive loading with frequency of 2 Hz and a displacement of 3 mm using a fatigue-testing machine, and the voltage and power were measured. We used digital image correlation and finite element method modeling to investigate the deformation of the silicone matrix. The coiled sheet specimen exhibited higher power with larger and more uniform deformation; however the sandwiched geometry exhibited better durability. The lower power of the sandwiched geometry was attributed to localized deformation because of friction at the interface between specimen and fixture, and the performance of this design was improved via the use of a lubricant. Copyright © 2015 John Wiley & Sons, Ltd.