• Korean Journal of Food Science and Technology
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• v.7 no.4
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• pp.229-237
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• 1975

An attempt was made to utilize the enzyme produced by Asp. oryzae as meat tenderizer. The production, purification, and various properties of proteinase produced by Asp. oryzae were investigated. Results obtained are as follow; 1. A strain which had the highest proteolytic activity was selected among 9 Aspergillus species. 2. Culture medium consisted of wheat bran 10g, 2% glucose, 0.03% urea and 0.1% $MgSO_4$ (pH 6.5). Mold was incubated at $30^{\circ}C$ for 3 days. 3. Enzyme extract from culture medium were fractionated with ammonium sulfate and purified by Sephadex G-75 column chromatography. 4. When pH of reaction mixture was controlled, maximal activity of proteinase by Asp. oryzae was obtained at pH 3, pH 6.6, $8.4{\sim}8.5$ and pH 10.0 to 10.5. Those results were interpreted to show that enzyme consists of acid proteinase, neutral proteinase and alkaline proteinase. Enzyme was stable at pH 6 to 10. 5. Opt. temperature for proteinase activity was $50^{\circ}C$, but enzyme was stable up to $40^{\circ}C$. 6. The proteinase was inhibited by $Ag^+$. It was also inhibited by EDTA. 7. When myofibrillar proteins were treated by proteinase from Asp. oryzae, ATPase activities of myofibrillar proteins changed remarkably. Accordingly, it was concluded that proteinase produced by Asp. oryzae were able to be used as meat tenderizer.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.3 no.3
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• pp.107-116
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• 1983

This paper is concerned with the permeability through a decomposed granite soil layer which is influnced by change of grain sizes and crushed soils made by varied compaction energy. The change in the content of crushed soils can be described in terms of the ratio of surface area ($S_w{^{\prime}}/S_w $). The experiments were carried out to obtain the relationships of the coefficient of permeability(K) versus the optimum moisture content($w_{opt}$) by the variable head permeability test with the samples that were preapared by compaction test. The results are found as follows; (1) By the change in compaction energy, the crush ratio increased whereas the void ratio decreased with a larger maximum dry density running in parallel with the zero air void curve. (2) The ratio of surface area was $0.33(P)^{0.96}$ in $S_w{^{\prime}}/S_w $ with no relation to the compaction energy. (3) The grain size which produced the largest crush of soil particles ranged from 0.5 to 1 millimetre (4) The relationship of K versus $e^3$/1+e appeared as a straight line on the full-log-scale paper under the optimum moisture state. (5) As the compaction energy was larger, the passing percentage of #200-sieve grains increased linearly. The increment in the surface area ratio was deemed to have been caused by the decreased in the permeability.