Purification and Characterization of Chinese Cabbage Pectinesterase

박관화,고영환 ( Kwan Hwa Park,Young Hwan Ko ) 한국토양비료학회 1982 한국토양비료학회 학술발표회 Vol.1982 No.28

Papaya중의 단백질 분해 효소와 Peroxidase의 열 불활성화

박관화(Kwan Hwa Park),김재욱(Ze Uook Kim),신재두(Jae Doo Shin),노봉수(Bong Soo Noh) 한국식품과학회 1979 한국식품과학회지 Vol.11 No.3

히드록삼酸 變法에 의한 牛乳脂肪定量

朴官和(Kwan Hwa Park),吳太廣(Tae Kwang Oh),盧奉洙(Bong Soo Noh) 한국식품과학회 1981 한국식품과학회지 Vol.13 No.2

무증자 (無蒸煮) 전분법에 의한 알코올생산 화학적 호화법 (糊化法)

박관화(Kwan Hwa Park),오병하(Byung Ha Oh),이계호(Ke Ho Lee) 한국응용생명화학회 1984 Applied Biological Chemistry (Appl Biol Chem) Vol.27 No.1

Ethanol fermentation from the chemically gelatinized starchy material was examined. The critical concentration of sodium hydroxide solution for gelatinization was dependent on the species of starch; 0.4M for potato and 0.6M for tapioca at room temperature. For alcohol fermention the starchy material was gelatinized by addition of sodium hydroxide solution, neutralized by sulfuric acid, and then yeast was added. The amount of CO₂ evolved during ethanol fermentation indicates that non-fermentable material was not produced from the starch by chemical gelatinization. In ethanol fermentation of potato and tapioca starch no significant difference was observed between the thermal and the chemical gelatinization.

Purification and Characterization of Chinese Cabbage Pectinesterase

고영환,박관화,Ko, Young-Hwan,Park, Kwan-Hwa Korean Society of Food Science and Technology 1984 한국식품과학회지 Vol.16 No.2

배추로부터 얻은 펙틴에스테라제 조효소액을 DEAE-셀를로오스 이온교환 수지를 통과시켜 두개의 분획F-A와 F-B를 분리했으며. 그중 주종을 이루고 있는 F-A는 DEAE-셀룰로오스 이온교환수지. CM-셀를로오스 이온교환수지를 통과시켜서 약 340배 정제하였다. F-A와 F-B는 비슷한 염효과를 나타내었는데, 최적 염농도는 $Ca^{++}$ $Mg^{++}$등 2가 양이온의 경우 $20{\sim}50mM$ $K^{+}$, $Na^{+}$등 1가 양이온의 경우 250mM부근이었다. 최적pH는 F-A와 F-B에 대해서 각각 8.0 및 $7.5{\sim}8.0$이였으며. 이들 두 분획은 pH $5.0{\sim}8.0$에서 적어도 한 시간동안 안정했다. F-A에 대한 Km은 펙틴기질에 대해서 0.01%이었다. F-A와 F-B의 최적온도는 각각 $48^{\circ}C$와 $55^{\circ}C$이었으나 $55^{\circ}C$에서 급격히 역가가 감소되었다. 열불활성화 경향은 1차반응을 나타내었으며 $35^{\circ}C{\sim}55^{\circ}C$사이에서 F-B의 D-Value는 F-A보다 커서 F-B가 F-A보다 열에 더 안정한 것으로 나타났다. 한편 Z-value는 F-A 의 경우 $10.5^{\circ}C$, F-B의 경우 $8.3^{\circ}C$이었다. Two fractions of pectinesterase from Chinese cabbage were isolated by ammonium sulfate fractionation, ion exchange chromatography on DEAE-cellulose and Sephadex G-150 gel filtration. The fraction F-A and F-B were purified approximately 340- and 10-fold. The similar salt effects and pH optima (pH 7.5-8.0) were obtained for the two pectinesterase fractions. The maximum activity of both two. fractions were obtained at 20-50mM of divalent rations and at 250mM of monovalent rations. The apparent Michaelis constant of the F-A was 0.01% for citrus pectin. The temperature optima for F-A and F-B were $48^{\circ}$ and $55^{\circ}C$, respectively and both fractions were stable in the region of pH 5.0-8.0 at room temperature. The thermal inactivation of the two fractions followed the first order reaction kinetics. From D and Z-values obtained the thermal resistance of the two fractions were characterized.

Papaya Latex에 있는 단백질분해효소(蛋白質分解酪素)들의 열불활성(熱不活性)에 관하여

노봉수,박관화,Noh, Bong-Soo,Park, Kwan-Hwa 한국식품과학회 1980 한국식품과학회지 Vol.12 No.3

파파이야 라텍스를 $(NH_4)_2SO_4$,분획 및 CM-cellulose column을 통과시켜 두개의 획분으로 분리하고 각 획분 별로 pH 7.0, $60{\sim}90^{\circ}C$에서 열 불활성 실험을 행하고 다음과 같은 열역학적인 자료를 얻었다. 1. fraction I 의 z-value는 $25^{\circ}C$이었고 $70^{\circ}C$에서 활성화 엔탈피 (enthalpy of activation) 89.5 kJ/mol, 활성화엔트로피 (entropy of activation) -44.0 kJ/mol K, 활성화 자유에너지(free energy of activation) 104.6 kJ/mol이었다. 2. fraction II 의 z-value는 $23^{\circ}C$이고 $70^{\circ}C$에서 활성화 엔트로피 -22.0 kJ/mol K, 활성화 자유에너지 104.2 kJ/mol이었다. 3. fraction I과 fraction II를 혼합한 경우의 z-value는 $24.6^{\circ}C$, $70^{\circ}C$에서 활성화 엔탈피 90.9 kJ/mol, 활성화 앤트로피 -38.8 J/mol K, 활성화 자유에너지 104.2 kJ/mol이었다. 4. 조 추출액의 z-value는 $23.2^{\circ}C$이고 $70^{\circ}C$에서 활성화 엔트로피 113.8 kJ/mol, 활성화 엔트로피 22.0 kJ/mol K, 활성화자유에너지 106.2 kJ/mol이었다. 이상의 결과에서 fraction I 이 fraction II 보다 열에 안정하다고 볼 수 있었고 파파이야 라텍스에 있는 단백질 분해 효소의 열 안정성은 주로 fraction I 에 기인하는 것 을 알 수 있었다. Proteases from papaya latex were partially purified by ammonium sulfate precipitation and separated into two fractions (Fraction I and II ) by carboxymethyl cellelose column chromatography. Each fraction, mixture of the two fractions, and crude extract of the papaya latex at pH 7.0 were inactivated at the range of $60{\sim}90^{\circ}C$ and thermal properties of the enzymes were investigated. In the thermal inactivation of fraction I, the enthalpy of activation was 89.5 kJ/mol; the entropy of activation, -44.0 J/mol K; the free energy of activation, 104.6 kJ/mol; z-value, $25^{\circ}C$. For fraction II, the enthalpy of activation was 96.5 kJ,/mol; the entropy of activation, -22.0 J/mol K; the free energy of activation, 104.0 kJ/mol; z-value, $23^{\circ}C$. For the mixture of fraction I and II, the enthalpy of activation was 90.9 kJ/mol; the entropy of activation, -38.8 J/mol·K; the free energy of activation, 104.2 kJ/mol; z-value, $24.6^{\circ}C$. For crude extract, the enthalpy of activation was 113.8 kJ/mol; the entropy of activation, 22.0 J/mol·K; the free energy of activation, 106.2 kJ/mol; z-value, $23.2^{\circ}C$. It was indicated that the fraction I was more heat-stable than the fraction II and this suggested that the thermal stability of the proteases in papaya latex is probably due to the fraction I.

쌀전분(澱粉) 분해물(分解物) 분석(分析)에 의한 세균성(細菌性) ${\alpha}-Amylase$의 작용(作用) 특성(特性)

김해영,박관화,Kim, Hae-Yeong,Park, Kwan-Hwa 한국응용생명화학회 1986 Applied Biological Chemistry (Appl Biol Chem) Vol.29 No.3

쌀의 생전분(生澱粉) 상태와 호화전분(糊化澱粉) 상태에 대한 전분분해효소의 작용특성과 이용방법(利用方法)을 조사하기 위하여 생전분과 호화전분에 세균성 ${\alpha}-amylase$ 및 glucoamylase를 처리하고, 생성되는 당의 종류를 정량하였다. 생전분에 ${\alpha}-amylase$를 작용시켰을 때에는 glucose(45%), maltese(33%), maltotriose(19%), maltotetrose 이상의 당류(3%) 등의 순서로 생성되었고, 호화전분에 작용(作用)했을 때에는 maltotriose(31%), maltose(31%), maltotetrose 이상의 고당류 (22%), glucose (15%)의 순서로 생성(生成)되었다. 한편 glucoamylase를 처리하였을 때에는 생전분과 호화전분에서 다같이 주로 glucose가 생성되었다. 전자현미경으로 분해된 상태를 확인한 결과, 생전분은 ${\alpha}-amylase$에 의하여 pinhole이 생성되고 전분입자의 표면침식이 잘되있고, 호화전분은 입자의 중앙부위에 공동(空洞)이 생성(生成)되었다. 이상의 결과(結果)로 보아 세균성 ${\alpha}-amylase$는 생전분 입자의 표면에 작용하여 말단기부터 glucose 및 maltose 단위로 분해하며 호화된 전분입자에는 임의의 장소에서 전분을 가수분해함을 알 수 있었다. The product specificity of Bacillus ${\alpha}-amylase$ on raw rice starch has teen studied by using HPLC and scanning electron microscopy (SEM). Analysis of starch degradation products digested by ${\alpha}-amylase$ showed considerable differences between raw and gelatinized rice. The hydrolysis of raw rice starch resulted in formation of more glucose and maltose than those of gelatinized starch. SEM revealed characteristic enzyme degradation patterns. Hollow curvatures were observed in gelatinized starch, indicating the substrate is hydrolyzed in the interior of the starch chain by Bacillus ${\alpha}-amylase$. In contrast, raw starch were hydrolyzed from the end of the substrate, resulting in pinholes over the surface of the starch granules.

하이드록시프로필화 옥수수 전분의 이화학적 특성

육철,백운화,박관화,Yook, Cheol,Pek, Un-Hua,Park, Kwan-Hwa 한국식품과학회 1991 한국식품과학회지 Vol.23 No.2

옥수수 전분을 propylene oxide와 반응시켜 치환도가 $0.031{\sim}0.147$되는 hydroxypropyl 옥수수 전분을 제조하여 물리화학적 특성을 규명하였다. Hydroxypropylation에 의하여 팽윤력, 용해도 및 물결합 능력이 증가하고 생전분의 효소 분해력이 높아졌으며 요오드 흡착강도가 낮아졌다. 아울러 hydroxypropylation에 의하여 전분의 결정화도도 감소되었다. 한편, 옥수수 전분을 hydroxypropylation시켰을 때 분자량 $1.34{\times}10^7$ 이상의 큰 분자는 감소하였고 $1.34{\times}10^7{\sim}1.18{\times}10^5$의 전분 분자는 증가하였다. Hydroxypropylation에 의하여 옥수수 전분 입자의 형태에는 별 변화가 없었으나 입자크기는 평균입경이 $13.9\;{\mu}m$에서 $16.0\;{\mu}m$로 증가하였다. Hydroxypropylated starches were prepared by reaction of corn starch with propylene oxide and their physicochemical properties were compared with those of the native starch. Swelling power, solubility and water binding capacity increased with the increase of hydroxypropylation. The hydroxypropylation of corn starch significantly reduced the extent of digestion and iodine absorption. Starch molecules larger than $1.34{\times}10^7{\sim}$ decreased whereas molecules ranging from $1.34{\times}10^7{\sim}1.18{\times}10^5$ increased by hydroxypropylation. Granule size increased by hydroxypropylation but this did not significantly affect the granule surface appearance by SEM. The hydroxypropylation improved the solubility and water binding capacity of corn starch.

저장 중 시금치의 클로로필 색소 성분에 영향을 주는 요인

이상화(Sang Hwa Lee),최은옥(Eun Ok Choe),이현규(Hyeon Gyu Lee),박관화(Kwan Hwa Park) 한국응용생명화학회 2001 Applied Biological Chemistry (Appl Biol Chem) Vol.44 No.2

Factors such as temperature (20, 60℃), pH (4.5, 7.0), gaseous phase (N₂, O₂), and light (0 lux, 5,000 lux), antioxidants and packaging conditions were investigated to study the effects of above factors on the chlorophyll components in spinach during storage. Regardless of other factors, as the storage temperature increased from 20℃ to 60℃ and pH decreased from 7.0 to 4.5, the contents of chlorophyll a and chlorophyll b in spinach decreased significantly (P$lt;0.05). The amounts of chlorophyll a and chlorophyll b in spinach stored in nitrogen gas were significantly (P$lt;0.05) lower than those in sample in oxygen phase. As the light intensity increased from 0 lux to 5,000 lux during storage, the contents of chlorophyll a and chlorophyll b in spinach significantly (P$lt;0.05) decreased. The antioxidants reduced the degradation of chlorophyll a in a model system during dark storage by minimization of free radical oxidation. The effectiveness of antioxidants decreased as following orders; α-tocopherol$gt;ascorbic acid$gt;β-carotene$gt;catechin$gt;quercetin$gt;rutin$gt;kaempherol$gt;caffeic acid$gt;chlorogenic acid$gt;ρ-coumaric acid$gt;ferulic acid. The degradation of chlorophyll a in a model system during light storage was minimized by antioxidants due to the reduction of singlet oxygen oxidation. The antidiscoloring potential of antioxidants decreased as following orders; β-carotene$gt;α-tocopherol$gt;ascorbic acid$gt;catechin$gt;quercetin$gt;rutin$gt;kaempherol$gt;caffeic acid$gt;chlorogenic acid$gt;ρ-coumaric acid$gt;ferulic acid. The amounts of chlorophyll a and chlorophyll b in freeze dried spinach packed with polyethylene bag were significantly (P$lt;0.05) lower than those in non-packed freeze dried spinach. The package of spinach in polyethylene bag with the combination of antioxidants could be used to minimize the degradation of chlorophyll components in spinach during storage.

예비열처리(豫備熱處理)에 의한 무우김치의 연화방지(軟化防止)

육철,장금,박관화,안승요,Yook, Cheol,Chang, Koom,Park, Kwan-Hwa,Ahn, Seung-Yo 한국식품과학회 1985 한국식품과학회지 Vol.17 No.6

숙성중 무우 김치 조직의 연부현상을 방지하기 위하여 예비열처리와 $CaCl_2$의 효과를 조사하고 이를 이용하여 무우조직의 경도가 높은 김치를 제조하였다. 무우조직중의 펙틴분해효소인 폴리갈락투로나제(PG)는 펙틴에스테라제(PE)보다 더 낮은 농도의 $CaCl_2$에서 저해되었고, PE의 최적온도는 $50{\sim}55^{\circ}C,$ PG는 $45^{\circ}C$이었다. 따라서 0.05M $CaCl_2$용액에서 $55^{\circ}C$로 2시간동안 열처리 하여 PE는 활성화 시키고 PG는 억제시킬 수 있었다. 최적조건하에서 예비열처리를 하여 김치를 제조한 후 냉장고($4{\sim}10^{\circ}C$에서 저장하려면 pH, 환원당, 경도, 펙틴분해효소의 역가 그리고 펙틴물질의 변화를 측정하였다. 처리구의 무우김치는 비교구보다 숙성중 계속해서 높은 경도를 유지하였고 조직내에 있는 PE는 숙성중 계속 감소하였으며 PG는 초기에는 감소하다가 저장 말기에 가서는 증가하였다. 저장중 펙틴물질 조성의 변화는 비교구가 처리구에 비해 열수가용 펙틴질이 더 많이 증가하였으며 Sodium hexa meta phosphate soluble 펙틴은 더 많이 감소하였다. The effects of preheating and calcium chloride on prevention of tissue softening was examined during fermentation and storage of radish root kimchi. In order to find the optimum condition of preheating treatment, activities of pectinesterase (PE) and polygalacturonase (PG) in radish root were measured with respect to $CaCl_2$ concentration and temperature. A maximum firmness was obtained with treatment in 0.05M $CaCl_2$ at $55^{\circ}C$ for 2hr which was optimum conditions for PE activity, while PG was inhibited at the $CaCl_2$ concentration of 0.05M. Firmness of radish root kimchi prepared by preheating treatment was decreased little during fermentation and storage for 25 days.