Ayumi Takemoto

Development of the rice-powder manufacturing system using underwater shock wave

Self-sufficiency in food is very low (about 40%) in Japan. Therefore, the rice powder is paid to attention because it can be processed to the udon (noodle) and bread etc. We has already developed the rice-powder disintegrator using the underwater shock wave by the electrode. But it has not been cleared what is the most suitable pressure vessel. The purpose of this study is to investigate the most suitable configuration of the pressure vessels for manufacturing the rice-powder using the underwater shock wave. Experimental conditions to manufacture the rice-powder (particle size is 100 μm) is clarified using this device. Moreover, the manufacturing efficiency of the rice-powder, the relation between the number of the shock wave generation and the grain degree of rice-powder is clarified.

A New Processing of Ginger Using the Underwater Shock Wave

In this study, a new processing technique of ginger using underwater shock wave has been studied. The extraction efficiency of ginger using controlled and shock wave method has been compared. The shock wave shows good improvement in the extraction efficiency of ginger.

On Sterilization Using the Underwater Shock Wave Under Non-Heating Environment

The establishment of the sterilization technology in non-heating environment is requested in the food industry and a lot of other fields. The existing sterilization technology using the high pressure is mainly liberating rapid pressure and a lot of loadings. In this research, the sterilization by a high pressure was tried by using the underwater shock wave caused by explosive. The detonating fuse was detonated with the percussion cap, and the shock wave was generated. Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Saccharomyces cerevisiae were used. The underwater shock wave barely causes heat. An excellent bactericidal effect of 100% was obtained in the maximum in the experiment that used S. cerevisiae.Copyright

Experimental Verification of the Softening of the Pork Using Underwater Shock Waves Generated by Wire Electrical Discharges

The National Institute of Technology, Okinawa College (OkNCT) has developed a food processing machine that generates underwater shock waves through wire electrical discharge. The machine can used for sterilization, milling flour, softening, and extraction among others. In this study, we experimentally examined the conditions for food softening using pork as the food material in experiments. Softness was revealed to be related to the distance of shock wave generation point from meat and the number of shockwave processing.

Effects of improving current characteristics of spark discharge on underwater shock waves

We have been developing a food-processing device that uses underwater shock waves generated by spark discharges at an underwater spark gap. Underwater shock waves can be used in food processing for softening, fracturing and sterilization. These technologies are attracting attention because the food is not heated during processing, so it does not change flavour. In this study, we develop a rice-powder manufacturing system using the fracturing effect provided by underwater shock waves. Because rice grains are very hard, the process must be applied repeatedly using a momentary high pressure to fracture the grains. The fast repeated generation of shock waves should provide high pressures from low energies. Therefore, we aim to achieve higher pressures from low energies expended by the underwater gap discharge. We increase the pulse compression rate by decreasing the circuit impedance of the device and increasing the charging voltage. Using optical observations and a pressure sensor, we measure the high pressure developed by the underwater shock wave and the rise time of the discharge current. We find that we can decrease the rise time of the discharge current by 17% while maintaining the peak current, and simultaneously increase the high pressure of the underwater shock wave by 135%.

Improvement of Extracted Volume of Sugarcane Using Underwater Shock Wave

The productivity improvement of food is necessary because the rate of food self-sufficiency of Japan is low. And then, the high efficient food processing is developed in Japan. On the other hand, the ratio of the production of sugarcane is high in the primary industry in Okinawa Prefecture. The rate of profit in the sugar manufacturing by sugarcane is lower than other primary industry goods, because the production cost is high. In this research, the sugar manufacturing method by sugarcane in high efficiency was developed using underwater shockwave. In this paper, to crush hard food like sugarcane, the pressure vessels of three dimensional oval structure is proposed. It is clear that the effect of the improvement of the juice extraction rate using the pressure vessel.Copyright

Basic Study on Pre-Processing by the Shock Wave for Freeze-Drying

In the food industry, it is hoping high value-aided product and the increase in efficiency of food processing. On the other hand, we get an experimental result that the load of the shock wave improves an extraction of food, and soften food. We tried to examine the effectivity of the shock wave as pre-processing for freeze-drying from the result in permeation character seen in the radish and so on. In the case of freeze-drying, the object tends to be limited to the small or thin one with size, from the sublimability in processing, the performance in case of the restoration and the viewpoint of the cost performance ratio. We report the result that shock wave loading was done to various food as pre-processing of freeze-drying.Copyright

Research on Sessile Organism Removal from Metal Using the Underwater Shock Wave

The sessile organism of the oyster and the barnacle, etc. causes friction between the surface of the ship and the water. Friction causes the deterioration of fuel cost. In addition, dry dock operation with putting the ship on the land or the diving operation, are needed for the removal of the sessile organism. These works require a very high cost. Various techniques for reducing friction resistance have been proposed. On the other hand, the method for the practical use is not popular still now. Authors tried to perform an experiment to remove the sessile organism on surface of the metal by using the underwater shock wave.

Extraction From Coffee Beans Using the Underwater Shock Wave

The coffee beverage widely liked all over the world as articles of taste is extracted from roasted and milled coffee beans. The aroma with volatility compounds is a feature of coffee. A lot of extraction methods of coffee were researched. In this research, the underwater shock wave loading was tried to the roasted coffee bean to improve the extraction efficiency. The coffee extracted from the hot water by the filter method after the underwater shock wave loading compared the amounts of the extraction by the freeze-drying processing. In addition, extracted the volatility compounds were compared by the gas chromatography analysis. As a result, the change in the content of an excellent effect of the extraction and a volatility compound was confirmed.Copyright

Exfoliation of Marine Organisms Technology by Using Underwater Shock Wave

Adhesion problem of marine organisms often becomes a problem, in the case of ship, marine floating construction and sluice gate of power plant. These make fluid resistance of a hull increase, cause a buoyancy fall, or cause reducing coolant etc. Although these are chiefly removed by manual operation now, immense expense and immense labors, such as personnel expenses and time and effort, are needed. We tried application of an underwater shock wave, in order to solve these problems. Interference of a shock wave and the mechanism of marine organisms exfoliation were explored using the explosive and PMMA plate, which imitated a marine organisms adhesion. The process of exfoliation of organisms from PMMA plate was observed by using of the high-speed camera.Copyright