• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.220.3-221
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• 2003

유과의 제조과정중 찹쌀의 장기간 수침시 미생물적 효소 작용에 의해 자연적으로 찹쌀 성분이 변화됨으로써 이들 변화가 유과의 독특한 질감 특성에 기여함이라는 사실에 기초하여, 본 연구에서는 효소 처리 및 미생물 접종에 의한 인위적인 방법을 통해 단시간 내에 이들과 유사한 성분 변화를 나타낼 수 있는 변형 찹쌀가루를 개발하여 유과 제조 가능성을 알아봄으로써 유과의 제조공정을 단축시킬 수 있는 방안을 모색하고자 하였다. 1. 각 처리시료에 따른 유과의 팽화도골 비교한 결과, 효소 처리군중 pH6.5$\longrightarrow$3.5, 35$^{\circ}C$(T1) 과 45$^{\circ}C$(T2) 처리군에서 28일간 수침시켜 제조한 유과와 비교될 만한 유사한 팽화도를 나타내었다. 2. 유과의 경도는 효소처리 시킬 경우 pH7.5$\longrightarrow$3.5와 $65^{\circ}C$처리군을 제외하고는 28일간 수침시켜 제조한 유과보다 부드러웠으나 peak 수에 있어서는 pH6.5$\longrightarrow$3.5처리군을 제외하고는 모든 처리군에서 감소하여 아삭아삭한 정도는 다소 떨어지는 것으로 나타났다. 3. 팽화도와 결도 결과와 유사하게 유과의 외관과 미세구조 역시 pH6.5$\longrightarrow$13.5(P1), 35$^{\circ}C$(T2)와 45$^{\circ}C$ (T3) 처리군에서 바람직한 유과의 외관을 나타내었고 미세하고 균일한 기공이 관찰되었다. 4. 유과의 관능검사 결과에서도, volume(용적 증가율), cell uniformity(기포의 균일한 정도)와 overall desirability(전체적으로 바람직한 정도)의 경우 효소처리시킨 시료중 pH6.5$\longrightarrow$3.5, 35$^{\circ}C$(T1)과 45$^{\circ}C$(T3)처리군이 28일간 수침시켜 제조한 유과와 비교될 만한 높은 점수를 보여 이를 처리군에서 바람직한 특성을 지닌 유과 제조가 가능한 것으로 나타났다.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.167-170
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• 2000

Proteolytic hydrolysis is one of the main enzymatic reaction of waste activated sludge (WAS) digestion. Pretense excreted from Bacillus stearothermophilus (ATCC 31197) showed optimum temperature of $75^{\circ}C$ for maxium heat stable proteolytic activity against azo casein. The dependency of $Ca^{2+}$, $Zn^{2+}$ on heat stability of proteolytic enzymes were measured with various concentrations. It was shown that $Ca^{2+}$ ion enhanced heat stability of these enzymes. Then thermophilic aerobic digestion (TAD) was performed using B. sterothermophilus with the addition of divalent ions. Performance of TAD process with ATCC 31197 activated by $Ca^{2+}$, $Zn^{2+}$ions in terms of dissolved organic carbon (DOC) concentration, extracellular protein concentration, and scanning electrion microscopy (SEM) analysis. The best result of protein reduction concentration in digestion test was obtained with the addition of 2 mM $Ca^{2+}$ ion.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 1994.07a
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• pp.15-16
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• 1994

옥수수 전분의 추출공정 개선 연구의 일환으로 메 밀 찰옥수수에 0-10 kGy범위의 감마선을 조사한 후 전분 추출시험과 추출전분의 이화학적 특성을 펴가하였다. 적정선량 범위의 감마선조사는 전분추출을 위한 침지시간을 기존 50시간에서 40시간으로 단축 시킬 수 있었으며, 환경기준 물질인 옥수수침지액(아황산용액)의 농도를 기존 0.8-1.2% 에서 0.2%로 크게 감소시킬 수 있었다. 또한 옥수수전분 추출액에 있어서 감마선 조사된 메옥수수와 찰옥수수는 비조사군에 비해 10-30% 이상의 추출율 증대효과를 나타내었다. 추 전분의 이화학적 특성시험에있어서는 두 시료 모두 감마선조사에 의해 alkaili number와 광투과도가 크게 증가 하였으며, 물 결합능력 및 swelling power는 다소 감소하는 경향이었다.전분의 색도는 조사군과 비조사군 사이에 유의적인 차이가 없었다. 효소반응 시험에서는 감마선 조사량이 증가함에 따라 효소반응 생성물인 포도당과 환원당 함량이 크게 증가하였다. Amylograph에 의한 물성시험에서는 감마선조사에 의해 전분호화액의 점도는 감소되었고, 그 경향은 메옥수수보다 찰옥수수에서 더욱 현저하였다. 또한 감마선의 이용은 옥수수 전분의 breakdown ratio 및 setback ratio를 향상시킬 수 있어 식품가공에서 전분의 고존도 사입 가능성을 시사하였다. 시사하였다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.4
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• pp.663-668
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• 2000

To develop natural intermediate flavoring substances, optimal processing conditions and qualities for two stage enzyme hydrolysate (TSEH) from low-utilized small longfinned squid were investigated. The optimal conditions for TSEH method were found as digestion with Alcalase (0.2% w/w-sample, pH 8.0) at 55$^{\circ}C$ 3 hours at the 1st stage and with Neutrase (exo-peptidase, 0.2% w/w-sample, pH 6.0) at 45$^{\circ}C$ for 2~3 hours at the 2nd stage. Among the method of water extract, autolytic extract and various kinds yields, transparency and organoleptic taste. From the results of chemical experiments and sensory evaluation, longfinned squid TSEH is flavorable as the natural intermediate taste-active substances for fisheries products such as soup base, squid-taste pasty and snacks.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.1
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• pp.83-87
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• 1999

Immobilization of amyloglucosidase (AMG) with chitosan microbead and its possible applications were evaluated. The diameter of chitosan inicrobead was about 1.2 mm and the optimum enzyme concentration for immobilization was 6 mg/ml. The relative activity of the immobilized enzyme was $97.8\%$ at pH 4.2 and $55^{\circ}C$ and the optimum condition for the immobilized enwme was the same to that of free enzyme. In case of temperature above $30^{\circ}C$, the activity of the immobilized enzyme was a little higher than that of free enzyme. The enzyme activities of both free and immobilized were stable for 6 months when stored at $35^{\circ}C$. The optimum temperatures of both enzymes for saccharification of the dextrinized starch were $55^{\circ}C$ while the relative activity of the immobilized enzlme was $62.6\%$.

• KSBB Journal
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• v.15 no.4
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• pp.342-345
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• 2000

A novel pre-purification method was developed for producing peroxidase to guarantee high purity and yield from plant cell cultures in large-scale process. This method was a simple and efficient procedure for the isolation and pre-purification of peroxidase from the biomass consisting of active clay treatment followed by cationic exchange chromatography. The use of active clay in the pre-purification process allows for rapid and efficient separation of peroxidase from interfering compounds and dramatically increases yield and purity of crude peroxidase for purification steps compared to alternative processes. This pre-purification process serves to minimize the buffer usage size and complexity of the HPLC operations for peroxidase purification. This process is readily scalable to a pilot plant and eventually to a production environment where mass production of material are expected to be produced.

• Korean Journal of Food Science and Technology
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• v.36 no.2
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• pp.299-305
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• 2004

Genetically Modified (GM) corn 'Bt11' was developed to promote insect resistance using crylA (b) gene derived from Bacillus thuringiensis. Effects of heat, pressure, and ${\alpha}-amylase$ on DNA fragment degradation in Btll corn were examined through PCR. Whereas DNA fragment degraded completely within 4 min at $150^{\circ}C$ and by autoclave, most remained after oil-frying, boiling, and drying-autoclave. Treatment of ${\alpha}-amylase$ enzyme did not affect DNA fragment degradation. Among 65 corn-processed foods analyzed, 9 were detected as GM corn-containing foods(13.6%).

• Journal of Life Science
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• v.14 no.1
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• pp.131-140
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• 2004

T7 bacteriophage gp4 is the replicative DNA helicase that unwinds double-stranded DNA by utilizing dTTP hydrolysis energy. The quaternary structure of the active form of T7 helicase is a hexameric ring with a central channel. Single-stranded DNA passes through the central channel of the hexameric ring as the helicase translocates $5'\rightarrow3'$ along the single-stranded DNA. The DNA unwinding was measured by rapid kinetic methods and showed a lag before the single-stranded DNA started to accumulate exponentially. This behavior was analyzed by a kinetic stepping model for the unwinding process. The observed lag phase increased as predicted by the model with increasing double-stranded DNA length. Trap DNA added in the reaction had no effect on the amplitudes of double-stranded DNA unwound, indicating that the $\tau7$ helicase is a highly processive helicase. Global fitting of the kinetic data to the stepping model provided a kinetic step size of 10-11 bp/step with a rate of $3.7 s^{-1}$ per step. Both the mechanism of DNA unwinding and dTTP hydrolysis and the coupling between the two are unaffected by temperature from $4∼37^{\circ}C$. Thus, the kinetic stepping for dsDNA unwinding is an inherent property of tile replicative DNA helicase.

• Applied Chemistry for Engineering
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• v.5 no.4
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• pp.681-697
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• 1994

The enzymatic hydrolysate of gelatin extracted from fish skin was fractionated and recycled through the membrane reactor according to the molecular weight for the purpose of using as functional material. In addition, the enzymatic hydrolysis conditions of gelatin, enzyme stability by membrane and mechanical shear, and effect on the long-term operational stability of the recycle membrane reactor were investigated. Using the pH-drop technique, Alcalase, pronase E and collagenase were identified as the most suitable enzymes for the hydrolysis of fish skin gelatin. The optimum hydrolysis conditions in the 1st-step membrane reactor(1st-SMR) by Alcalase were enzyme concentration 0.2mg/ml, substrate-to-enzyme ratio(S/E) 50(w/w), $50^{\circ}C$, pH 8.0, reaction volume 600ml and flow rate 6.14ml/min. In the 2nd-SMR by pronase E were enzyme concentration 0.3mg/ml, S/E 33(w/w), $50^{\circ}C$, pH 8.0, reaction volume 600ml and flow rate 6.14ml/min. In the case of 3rd-SMR, enzyme concentration 0.1mg/ml, S/E 100(w/w), $37^{\circ}C$, pH 7.5, reaction volume 600ml and flow rate 10ml/min. Decreased enzyme activities by mechanical shear and membrane were 30% and 15% in the 1st-SMR, were 14% and 5% in the 2nd-SMR, and 18% and 8% in the 3rd-SMR, respectively. Under the optimum conditions, the degree of hydrolysis in the 1st, 2nd and 3rd-SMR were 3.5%(Kjeldahl method, 87%), 3.1%(77%) and 2.7%(70%), respectively. The productivity of hydrolysate in the continuous three-step membrane reactor was 430mg per enzyme(mg) for 10 times of volume replacements.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.49 no.3
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• pp.277-283
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• 2023

Fraxinus rhynchophylla Hance (F. rhynchophylla) is a traditional medicinal plant that has been widely used in East Asia and has been used for chronic bronchitis, bacterial dysentery and improved eyesight. F. rhynchophylla contains various type of coumarins such as esculin, esculetin, fraxin and fraxetin. Esculetin possesses versatile activities including antioxidant, anti-inflammatory, antimicrobial, anticancer properties and improvement of atopic dermatitis. However, there is no research on the process of increasing active components in F. rhynchophylla. The objectives of the present study were to apply biotransformation technology to F. rhynchophylla for increasing the content of esculetin, and enhancing anti-inflammatory and antioxidant activities. F. rhynchophylla extract (FRE) treated with viscozyme L (FRE-VL) showed 3.1 times higher content of esculetin than FRE, and exhibited effects such as increased anti-inflammatory activity and DPPH radical scavenging activity. Based on the these results, it is concluded that biotransformed FRE-VL could be potentially applicable as a new active ingredient in the cosmetic field.