• Asian-Australasian Journal of Animal Sciences
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• v.20 no.6
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• pp.994-1001
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• 2007

Changes in shear force value, transverse sections, myofibrils and intramuscular connective tissue of bovine skeletal muscle exposed to the combination of high-pressure up to 400 MPa and heat (30 and $60^{\circ}C$) were studied. The shear force value decreased by pressure-heat treatment up to 200 MPa at 30 and $60^{\circ}C$, and then slightly increased over 200 MPa at $30^{\circ}C$. Shear force values of treated muscles were lower than those of untreated ones. Gaps between muscle fibers in the untreated muscle were a little clear, and then they became very clear in the treated muscles up to 200 MPa at 30 and $60^{\circ}C$. However, the gaps reduced significantly over 200 MPa at $30^{\circ}C$. The remarkable rupture of I-band and loss of M-line materials progressed in the myofibrils with increasing pressure applied. However, degradation and loss of the Z-line in myofibrils observed in the muscle treated at $60^{\circ}C$ was not apparent in the muscle treated at $30^{\circ}C$. The length of the sarcomere initially contracted by pressure-heat treatment of 100 MPa at $30^{\circ}C$ seemed to have recovered with increase of the pressure up to 400 MPa. In the muscle treated at $60^{\circ}C$, the length of sarcomere gradually decreased with increase of the pressure up to 400 MPa. In the treated muscles, changes in the honeycomb-like structure of endomysium were observed and accelerated with increase of the pressure. A wavy appearance clearly observed at the inside surface of endomysium in the untreated muscles gradually decreased in the treated muscles with increase of the pressure. Tearing of the membrane was observed in the muscles treated over 150 MPa at $30^{\circ}C$, as observed in the sample pressurized at 100 MPa at $60^{\circ}C$. The roughening, disruption and fraying of the membrane were observed over 200 MPa at $60^{\circ}C$. From the results obtained, the combination of high-pressure and heat treatments seems to be effective to tenderize tough meat. The shear force value may have some relationship with deformation of intramuscular connective tissue and myofibrils.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7227-7236
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• 2015

The survey revealed that, due to the discharge characteristics of seafood wastewater, irregular inflow loads were caused, making it difficult to treat the wastewater safely. It is crucial for the operation of pressure and floating tanks for the treatment of high-concentration organic wastewater such as seafood wastewater. The survey of operation factors for the pressure and floating tanks revealed this: A/S ratio 0.05 (design criteria 0.01), the pressurized air pressure 8bar(design criteria 6bar), the pressure tank pressure 6bar (design criteria 4.5bar), and HRT 60sec(design criteria: 10sec). Also, the recirculation rate was changed to over 40%(design criteria: 30%), and the surface load rate was changed to under $13.7m^3/m^2{\cdot}hr$(design criteria: under $17.7m^3/m^2{\cdot}hr$); thus, compared to the initial design criteria, the operation factors were changed according to inflow characteristics, thus enhancing the pressure and floating tank performance. The survey of inflow load revealed BOD 140.7%, $COD_{Mn}$ 120.32%, and SS 106.3%, compared to the inflow design criteria, as well as T-N 135.5% and T-P173.3%, higher than the design criteria. The survey of the treatment facility annual operation cost revealed high portions in sludge treatment cost(27.7%) and chemicals costs(26.0%), and the sludge treatment cost will likely further increase due to the ban on ocean dumping. The unit cost for the treatment of seafood wastewater was found to be KRW 3,858 per ton, more than 27 times higher than the sewage treatment cost(KRW 142.6/ton), presumably because the seafood wastewater contains high-concentration organic substances and nutritive salts.