• 한국수산과학회지
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• 제54권4호
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• pp.543-551
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• 2021

Changes in gluten surface hydrophobicity, which play an important role in the functional characteristics of protein, were measured according to various protein concentrations, pH levels, electrolytes concentrations, and alginate molecular weights using 8-anilino-1-naphthalene sulfonic acid (ANS) as a fluorescent probe. Gluten surface hydrophobicity decreased as gluten concentration increased, reaching a maximum pH of 7.0. The effects of alginate molecular weights and alginate concentration on the surface hydrophobicity, emulsifying activity index (EAI), and emulsion stability index (ESI) of gluten-sodium alginate dispersion (GAD) were measured. Gluten surface hydrophobicity rapidly increased the asl NaCl concentration of gluten solution up to 300 mM and showed no significant increase above 300 mM. However, gluten surface hydrophobicity notably decreased until the concentration of CaCl₂ and MgCl₂ reached 30 mM, indicating no significant variations above 30 mM. GAD surface hydrophobicity increased as the concentration and molecular weight of sodium alginate increased, however, gluten concentration increased as the GAD surface hydrophobicity decreased. The EAI and ESI of GAD increased as both molecular weight and concentration of sodium alginate increased.

• 한국미생물·생명공학회지
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• 제24권2호
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• pp.206-212
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• 1996

The strain producing bioemulsifier was isolated from soil samples. The isolated strain was identified as the genus Acinetobacter through its morphological, cultural and physiological characteristics. The highest emulsification activity and stability by Acinetobacter sp. BE-254 was observed after 5 days of cultivation in the culture medium containing n-hexadecane 4%, NaNO$_{3}$ 0.2%, KH$_{2}$PO$_{4}$ 0.01%, MgSO$_{4}$-7H$_{2}$O 0.01%, CaCl$_{2}$ 0.01%, and yeast extract 0.01%. The optimum pH and temperature for bioemulsifier production were pH 7.0 and 30$\circ$C, respectively. Furthermore the most of bioemulsifier was produced during the exponential growth phase, and this suggested that the bioemulsifier production was growth-associated. The bioemulsifier showed good emulsification activity on various emulsifying substrates such as hydrocarbons, edible oils, and petroleum fractions.

• 한국응용과학기술학회지
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• 제33권1호
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• pp.155-167
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• 2016

Surface-active substances in defatted rapeseed cake were obtained using a supercritical fluid extraction method. Then, it was purified by removing sinapine in the extract through a series of steps using a mixed solvent: diethyl ether and ethyl acetate (1:1, v/v). Emulsifying properties of purified surface-active substances were investigated, including fat globule size, zeta potentials and creaming stability and its antioxidant activity in emulsion systems were also studied by peroxide value and $^1H$-NMR spectrum. It was found that fat globules in emulsions with purified surface-active substances were much smaller than ones with the unpurified. In addition, as pH of the emulsion lowered and with increasing NaCl concentration in the emulsion, they were observed to increase, which led to worse creaming stability. These properties were reflected in changes of zeta potentials of emulsions. The oxidative stability was better in emulsions with purified surface-active substances than ones with Tween 20 or commercial lecithin, possibly resulted from the existence of sinapic acid in the extract. It was concluded that purified surface-active substances from defatted rapeseed cake could be simultaneously used as emulsifier and antioxidant agent in emulsion system.

• 한국수산과학회지
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• 제34권4호
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• pp.320-326
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• 2001

어분단백질의 이용성을 높이기 위한 가식성 혹은 생분해성 필름가공을 목적으로 알칼리 처리하여 제조된 FMPI의 물성과 이물성과 ester 화합물의 필름 투과율과 인장강도에 미치는 영향을 조사한 결과는 다음과 같다. 어분으로부터 알칼리처리하고 추출조건을 달리하여 제조된 FMPI의 추출량은 추출시간이 증가함에 따라 증가하였다. FMPI의 소수성은 추출시간 1시간일 때 가장 높게 나타났다가 그 이상 추출시간이 경과함에 따라 감소하였다 유화활성은 추출시간이 5시간까지 증가함에 따라 급격한 증가를 보였으며, 유화안정성은 추출시간 2시간까지 추출시간의 증가에 따라 급격한 감소를 보여 유화활성과 상반된 결과를 나타내었다. 점도는 pH가 2일 때 가장 높게 나타났고 pH가 4일 때 가장 점도가 낮게 나타났다. 첨가하는 가소제의 농도가 증가할수록 필름의 ethyl acetate의 투과도는 증가하였다. 가소제의 종류별에 따른 ethyl acetate의 투과도는 polyethylene glycol, glycerol 및 sorbitol 첨가 필름 순으로 높게 나타났으며, ester 화합물 중에서는 ethyl formate의 투과속도가 가장 높았다. 온도가 증가함에 따라 ethyl acetate의 필름 투과속도는 증가하였다. FHPI의 표면소수성이 증가하면 필름의 인장강도가 증가하였다. 필름의 신장율은 FMPI의 표면소수성보다 가소제의 종류에 더 큰 영향을 받았다.

• 한국수산과학회지
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• 제20권6호
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• pp.582-590
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• 1987

말쥐치육 단백질의 가수분해물로 합성한 plastein을 식품단백질원으로서 고도이용 가능성을 구명하기 위하여 그의 기능성을 FPC 및 egg albumin과 비교 검토하였으며, 아울러 SEM에 의한 plastein 형상도 관찰하였다. 용해도는 plastein이 FPC 보다 용해도가 월등히 높았고, Glu-papain plastein은 pH변화에 관계없이 용해도가 $95\%$이상으로 높았으나 Leu-papain plastein의 용해도는 매우 낮았다. 가열시간이 길어짐에 따라 FPC는 용해도가 감소하는 경향을 보였으나 Glu-papain plastein은 가열시간에 관계없이 용해도가 $81\%$이상이었다. 분산성은 Glu-papain plastein과 protease plastein이 egg albumin의 그것과 비슷하였으나 ekfms plastein은 다소 분산성이 낮았다. 보수력은 FPC가 egg albumin보다 낮았으며, 지방흡수력은 Leu-papain plastein이 1.88ml/g으로 가장 높았고, 다른 plastein은 egg albumin의 그것과 비슷하였다. 유화성은 Leu-papain plastein이 $61.2\%$로 가장 높았으나 Glu-papain plastein은 $50.7\%$로 가장 낮았다. 유화안정성도 이와 같은 경향이었다. 포말성은 Leu-papain plastein과 Glu-papain plastein이 각각 $373\%,\;360\%$로 egg albumin의 $130\%$ 보다 우수하였다. 포말안정성은 모든 plastein이 50시간 이후에 소실되어 egg albumin의 36시간에 비해 높았다. 점도는 모든 plastein이 egg albumin에 비해 낮았다. SEM을 통해 본 plastein의 형상은 처리한 효소 종류에 따라 다소 차이를 보였으며, Glu-papain plastein과 Leu-papain plastein은 다른 plastein에 비해 특이한 부드러운 형상을 나타내었다.

• 한국식품과학회지
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• 제32권5호
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• pp.1093-1101
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• 2000

잣 단배질 추출물(PNPE)의 유화력은 등전점(pH 3.8 부근)을 전후하여 산성 영역보다는 알칼리성 영역에서 높은 값을 보였으며, 1%의 PNPE를 함유한 경우에 pH 8.0에서 유의적으로(p<0.05) 가장 높은 값 (약 6.44 $m^2/g$)을 나타내었으며, 3% PNPE를 함유한 유화용액의 경우 pH 4.0에서 가장 낮은 유화력 지표(약 0.10 $m^2/g$)를 나타내었다. PNPE의 유화안정성은 3%의 PNPE를 함유한 경우에 pH 8.0에서 약 20으로 가장 높게 나타났으며, 1%의 PNPE를 함유한 경우에는 높은 유화력에도 불구하고 전 pH 범위에서 5 이하의 낮은 값을 나타내었다. 잣 탄수화물 추출물(PNCE)의 경우 유화력은 PNPE와 달리 산성에서 알칼리성 영역으로 갈수록 지속적으로 증가하는 경향을 보였으며 pH 5.0 이후에 급격히 증가하였다. PNCE의 유화안정성은 PNCE의 함유량이 증가할수룩 증가하는 경향을 보였으며, 이들 구성 성분들은 lecithin에 비하여 약 $2.5{\sim}4.5$ 배 정도 낮은 유화특성을 나타내었다. 그리고 PNPE를 함유한 유화용액의 유동특성은 농도에 관계없이 pH 7.0과 8.0에서 뉴우톤성 유체(n=1, $r^2>0.99$)에 가까운 특성을 보였으며, 특히 3%와 5%의 PNPE를 함유한 경우에는 pH 3.0에서도 뉴우톤성 유체에 가까운 특성을 나타내었으나, PNCE를 함유한 유화용액의 경우는 농도 및 pH에 관계없이 의가소성 유체의 특성을 나타내었다. 또한 유화용액의 색도는 PNPE 및 PNCE의 농도에 관계없이 모두 pH 3.0과 7.0 및 8.0에서 유의적으로 (p<0.05) 높은 L값과 b값 그리고 ${\delta}E$값을 보였으며, a값은 이와 반대로 낮은 값을 나타내었다.

• Preventive Nutrition and Food Science
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• 제1권1호
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• pp.53-58
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• 1996

The characterstics of the soy protein curd(eczyme-, HCI- and Ca-surd) were shown by scanning electron micrographs and gel electrophoreis. The emulsion stability of enzyme-curd showed high value in the range of pH 2~10and wide range of temperature(20~8$0^{\circ}C$). While at the isoelectric point(pH5.0), the emulsion stability of the HCI-and Ca-curd was decreased remarkably, and the emulsion stability of temperature was reduced quickly to the 60% and 40% at the 4$0^{\circ}C$. The foam stability of enzyme-curd was slightly higher than that HCI-and CA-curd in all ranges of pH and temperature. The feature of SEM of enzyme-cured produced degradation products faster than that of the HCI- and Ca-curd.

• 한국식품조리과학회지
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• 제5권2호
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• pp.9-17
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• 1989

This study was carried out in order to study the emulsifying properties of kidney bean protein isolate. Kidney bean protein isolate was tested for the purpose of finding out the effect of pH, addition of NaCl, and heat treatment on the solbulity and emulsion capacity, emulsion stability, surface hydropobicity and emulsion viscosity. The results were summarized as follows. 1 The solubility of kidney bean protein isolate was affected by pH and showed the lowest value at pll 4.5 which is isoelectric point of kidney bean isolate. When the kidney bean protein isolate was heated, the highest value observed at pH 2 and pH 7 was 96.11%, 97.41% respectively. 2. The emulsion capacity of kidney bean protein isolate was not significantly different with each pH. With addition of NaCl, emulsion capacity decreased steadily. When heated thr highest value observed at pH 2 and pH 7 was 82.91 ml oil/100 mg protein ($60^{\circ}C$), 82.08 m1 oil/100 mg protein ($80^{\circ}C$) respectively. 3. The emulsion stability was significantly higher at pH 4.5 than that of pH 2 and pH 7 (p 0.05) When NaCl was added, emulsion stability was generally increased after 2hrs. When heated, the highest value observed at pH 2 and pH 7 was 21.25% ($80^{\circ}C$),23.7%($100^{\circ}C$) respectively after 2hrs. 4. Surface hydrophobicity increased sharply as 0.2 M NaCl was added to pH 4.5. When heated, the surface hydrophobicity increased as the temperature increased. 5. The highest value of emulsion viscosity was observed at pH 4.5 and pH 7 when 0.2 M NaCl was added. Under heat treatment, the highest value was 48,000 cps at pH 4.5 ($40^{\circ}C$). In the case of pH 7, the highest value was 105,000 cpa at $100^{\circ}C$.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2001년도 제3회 부산.경남지부 심포지엄
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• pp.14-28
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• 2001

As basic study for purpose bioremedation in oil-contaminated environment, Primarily, we isolated biosurfactant producer- strains utilized of oil-agar plate, and measured surface tension and emulsifying activity. We investigated in oil-contaminated soil and sea water. In this laboratory, Pseudomonas sp. EL-012S strain isolated from oil-contaminated soil was able to product novel biosurfactant under the optimal culture condition. Its condition was n-hexadecane 2.0%, NH$_4$NO$_3$0.4%, Na$_2$HPO$_4$0.6%, KH$_2$PO$_4$0.4%, MgSO$_4$.7$H_2O$ 0.02%, CaCl$_2$.2$H_2O$ 0.001%, FeSO.7$H_2O$ 0.001%, initial pH 7.0 and aeration at 3$0^{\circ}C$, respectively. This biosurfactant was produced in both late-exponential and early-stationary phase. The biosurfactant from Pseudomonas sp. EL-012S was composed of carbohydrate, lipid and protein. The purified-biosurfactant was examined two (biosurfactant type I, II) with the silica gel G60 column chromatography and the purified biosurfactant confirmed thin layer chromatography, high performed liquid chromatography and gas chromatography. The biosurfactant type I involved in carbohydrate-lipid-protein characteristics lowered surface tension of water to 27dyne/cm and interfacial tension 4.5dyne/cm aginst to n-hexadecane and the biosurfactant type B involved in carbohydrate lipid characteristics lowered surface tension of water to 30dyne/cm and interfacial tension 8dyne/cm against to n-hexadecane. Specially type I had the properties such as strong emulsifying activity, emulsion stability, pH-stability, thermo-stability, high cleaning activity and forming ability.

• 한국식품과학회지
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• 제18권6호
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• pp.468-474
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• 1986

대두단백질의 용해도, 소수성, 에멀젼의 유동특성, 물-기름 계면에서의 단백질 흡착 및 계면장력과 유화 특성과의 관계를 연구 검토 하였다. 등전점 부근에서 단백질의 유화능력과 유화안정도가 최소였으며, 단백질 용액의 pH가 이로부터 산성과 알칼리성 쪽으로 갈수록 유화특성이 증가하는 경향으로, 대두단백질의 용해도와 비슷한 경향을 보였다. 에멀젼의 온도가 증가함에 따라 $50^{\circ}C$까지는 유화형성능력이 증가하다가 그 이상에서는 약간 감소하였으며, 유화안 정도는 온도 증가에 따라 계속 감소하는 경향을 보였다. 인산염이 존재할 경우를 제외하고는 전반적으로 염은 유화특성을 감소시켰다. 단백질의 소수성은 온도가 증가함에 따라 증가하였으며, pH가 낮아질수록 약간 증가하는 경향을 보이다가 등전정 이하 산성영역에서 급격히 증가하였다. 기름-물 계면에서 단백질의 최대 흡착량은 pH2.0에서 $0.78mg/m^2$로 가장 높았으며. 다음 pH7이었고, 등전점인 pH4에서 가장 낮았다. 대두단백질이 존재하지 않을때 물-기름 계면장력은 19.76dyne/cm 이었으나 단백질이 존재할 경우 각 조건에 따라 다소 차이는 있으나 11.45-18.08dyne/cm로 전반적으로 저하되었다.