<i>In Vitro</i>Antioxidative Activity and Antihypertensive Activity of Soy Sauce Cake Derived from the Manufacturing of Japanese Style Fermented Soy Sauce

As the manufacture of soy sauce produces a large quantity of soy sauce cake as one of food processing waste, it is necessary to search for possible ways for their utilization. Chemical composition of soy sauce cake was analyzed to use as a material of high-value functional ingredients. The results showed that soy sauce cake could be potentially used as functional ingredients rich in proteins, with high antioxidative activitiy, free radical scavenging activity, and antihypertensive activity. Based on their IC50 values, the hydrolysates from soy sauce cake were more significantly effective against superoxide anion radicals and ACE, compared with hydroxyl radicals and DPPH radicals. The present study indicates that a large amount of soy sauce cake can be used as source of proteins with good antioxidative activity, free radical scavenging activity, and antihypertensive activity. The utilization of soy sauce cake may be also to contribute to reduce food processing wastes and to resolve an environmental problem.

The Influence of Phlorotannins and Bromophenols on the Feeding Behavior of Marine Herbivorous Gastropod <i>Turbo cornutus</i>

The influence of phlorotannins and bromophenols on the feeding behavior of marine herbivores was determined using bioassay of Turbo cornutus. It was found that phloroglucinol and its oligomers isolated from the brown alga Eisenia bicyclis (eckol, fucofuroeckol A, phlorofucofuroeckol A, dieckol, and 8,8’-bieckol) had a deterrent effect against feeding behavior of T. cornutus in the concentration of algal body, respectively. In the case of the examination of 0.1 mM concentration, although fucofuroeckol A and phlorofucofuroeckol A significantly reduced feeding by T. cornutus, phloroglucinol and 8,8’-bieckol did not show any significant influence on feeding behavior, and eckol and dieckol had stimulating activity. 2,4-Dibromophenol and 2,4,6-tribromophenol, which are major components of extracellular secretions from Eisenia and Ecklonia species, caused the death, the torpidity, and the decreased appetite of T. cornutus at the concentration of 0.1 mM. In addition, 2,4-dibromophenol had strong feeding deterrent activity at the concentration of 1 μM. These results indicate that phlorotannins and bromophenols act as chemical defense agents of brown algae against environmental stresses such as the herbivore attack.

Functional Property of Honey from <i>Echium vulgare</i>

Chemical property of honey from Echium vulgare was investigated. In comparison with other honey species, the con-tents of total phenolic compounds and total flavonoids were the highest. α-Amylase activity was also extremely high: about three to nine hundred times as much as those of other honey species. The antioxidative activity of honey was investigated using four different methods. Honey from E. vulgare showed the best performance in inhibiting lipid peroxidation and scavenging superoxide anion radicals, hydroxyl radicals, and DPPH radicals. Moreover, it exhibited stronger inhibition activity of ACE. It is known that higher antioxidative activity and scavenging activity against active oxygen species in honey species related to their colour. In the present study, however, it suggests that the phenolics in honey from E. vulgare with yellow gold colour might be the major active component responsible for the strong antioxidative activity and radical scavenging activity.

Static and dynamic evaluations of acoustic positioning system using TDMA and FDMA for robots operating in a greenhouse

Acoustic positioning system has great potential to be applied in a greenhouse due to its centimeter-level accuracy,low cost,and ability of extensive greenhouse coverage.Spread Spectrum Sound-based local positioning system(SSSLPS)was proposed to be a navigation tool for multiple agricultural robots by the authors'research team.However,to increase the system capacity for positioning multiple robots in a greenhouse,the near-far problem caused by the interference between speakers needs to be overcome.The use of different access methods,Time Division Multiple Access(TDMA)or Frequency Division Multiple Access(FDMA),is essential in the SSSLPS system for solving the near-far problem.The static positioning in a greenhouse was first evaluated by setting different parameters to determine the optimal signal setting for a dynamic experiment.From that,the moving robot tests were added with a motion capture system and tested the performance of TDMA and FDMA.The results demonstrated that TDMA can be used in a stationary sound-based positioning system with 12.2 mm accuracy,but it has a time delay problem in dynamic positioning.A simulation was designed to mimic the position error increases with different moving speeds.Although FDMA has the sound damping problem in high-frequency regions creating a peak detection issue,it achieved a higher accuracy with an average position error of 62.1 mm compared to 180.3 mm of TDMA.This study shows that the TDMA method is suitable for static measurements,while the FDMA method is suitable for measuring dynamic objects and controlling mobile robots.

The Effect of Spherical Surface on Noise Suppression of a Supersonic Jet

Experiments were carried out to eliminate the screech tone generated from a supersonic jet. Compressed air was passed through a circular convergent nozzle preceded by a straight tube of same diameter. In order to reduce the jet screech a spherical reflector was used and placed at the nozzle exit. The placement of the spherical reflector at the nozzle exit controlled the location of the image source as well as minimized the sound pressure at the nozzle exit. The weak sound pressure did not excite the unstable disturbance at the exit. Thus the loop of the feedback mechanism could not be accomplished and the jet screech was eliminated. The technique of screech reduction with a flat plate was also examined and compared with the present method. A good and effective performance in canceling the screech component by the new method was found by the investigation. Experimental results indicate that the new system suppresses not only the screech tones but also the broadband noise components and reduces the overall noise of the jet flow. The spherical reflector was found very effective in reducing overall sound pressure level in the upstream region of the nozzle compared to a flat plate. The proposed spherical reflector can, accordingly, protect the upstream noise propagation.