• 한국식품조리과학회지
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• 제9권1호
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• pp.43-51
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• 1993

Buckwheat protein isolate was tested for the effects of pH, addition of sodium chloride and heat treatment on solubility, emulsion capacities, emulsion stability, surface hydrophobicity, foam capacities and foam stability. The solubility of buckwheat protein isolate was affected by pH and showed the lowest value at pH 4.5, the isoelectric point of buckwheat protein isolate. The solubility significantly as the pH value reached closer to either ends of the pH, i.e., pH 1.0 and 11.0. The effects of NaCl concentration on solubility were as follows; at pH 2.0, the solubility significantly decreased when NaCl was added; at pH 4.5, it increased above 0.6 M; at pH 7.0 it increased; and at pH 9.0 it decreased. The solubility increased above $80^{\circ}C$, at all pH ranges. The emulsion capacity was the lowest at pH 4.5. It significantly increased as the pH approached higher acidic or alkalic regions. At pH 2.0, when NaCl was added, the emulsion capacity decreased, but it increased at pH 4.5 and showed the maximum value at pH 7.0 and 9.0 with 0.6 M and 0.8 M NaCl concentrations. Upon heating, the emulsion capacity decreased at acidic pH's but was maximised at pH 7.0 and 9.0 on $60^{\circ}C$ heat treatment. The emulsion stability was the lowest at pH 4.5 but increased with heat treatment. At acidic pH, the emulsion stability increased with the increase in NaCl concentration but decreased at pH 7.0 and 9.0. Generally, at other pH ranges, the emulsion stability was decreased with increased heating temperature. The surface hydrophobicity showed the highest value at pH 2.0 and the lowest value at pH 11.0. As NaCl concentrationed, the surface hydrophobicity decreased at acidic pH. The NaCl concentration had no significant effects on surface hydrophobicity at pH 7.0, 9.0 except for the highest value observed at 0.8 M and 0.4 M. At all pH ranges, the surface hydrophobicity was increased, when the temperature increased. The foam capacity decreased, with increased in pH value. At acidic pH, the foam capacity was decreased with the increased in NaCl concentration. The highest value was observed upon adding 0.2 M or 0.4 M NaCl at pH 7.0 and 9.0. Heat treatments of $60^{\circ}C$ and $40^{\circ}C$ showed the highest foam capacity values at pH 2.0 and 4.5, respectively. At pH 7.0 and 9.0, the foam capacity decreased with the increased in temperature. The foam stability was not significantly related to different pH values. The addition of 0.4 M NaCl at pH 2.0, 7.0 and 9.0 showed the highest stability and the addition of 1.0 M at pH 4.5 showed the lowest. The higher the heating temperature, the lower the foam stability at pH 2.0 and 9.0. However, the foam stability increased at pH 4.5 and 7.0 before reaching $80^{\circ}C$.

• 한국건축시공학회지
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• 제9권4호
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• pp.63-73
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• 2009

최근 건설생산현장에서는 경제가 성장함과 동시에 사회적으로 급격하게 증가하는 건축물의 수요를 충족시키기 위해서 표준화, 대량 생산화가 가능한 건식 공법이 각광을 받고 있다. 이러한 현실에 부응하여 에너지 절감효과 및 공사기간 단축, 다양한 형태로 적용이 가능하고 경제성을 가지는 샌드위치 패널이 많이 사용되고 있다. 샌드위치 패널의 형태는 양면 도장 강판 사이에 유기계 및 무기계 단열재를 합성한 복합 자재이다. 유기계 단열재는 PUR(Poly-uretane foam) 및 EPS(Expanded poly-stylene foam) 등이 사용되며, 무기계 단열재는 Glass wool 및 Mineral wool 등이 사용된다. 유기계 단열재는 화재 시 불이 잘 붙어 대피할 수 있는 시간 부족과 유독가스의 발생으로 인명피해가 크게 발생할 수 있지만, 무기계보다 가격이 싸서 유기계 재료를 사용한 샌드위치 패널이 많이 사용되고 있다. 반면, 무기계 단열재 중 경량기포콘크리트는 단열성과 내화성, 경량성 등이 뛰어나기 때문에 샌드위치 패널에 적용하여 유기계의 단점을 해결하기 위한 많은 연구가 수행되어져 왔다. 단열성 및 내화성, 경량성이 뛰어난 경량기포콘크리트는 기포제를 활용하여 시멘트 경화체 내에 다량의 공극을 발생시켜 제조한 것으로서 역학적 특성은 사용되는 기포제와 발포제의 종류에 따라 많은 영향을 받게 된다. 기포제는 계면활성작용에 의해 물리적으로 기포를 도입하는 것으로써 공기량은 최고 85%까지 생성될 수 있으며, 크게 계면활성제계, 가수분해 단백질계로 구분될 수 있다. 계면활성제계 기포제는 수용액 상에서 기포시키면 안정되고, 점성이 높은 기포가 생기지만 시멘트 슬러리와 혼합 시 안정성이 저하되어 서로 연속된 형태의 기포를 형성한다. 가수분해 단백질계 기포제는 계면활성제계 기포제와는 달리 시멘트 슬러리와 혼합 시 안정되고 서로 독립적인 형태의 기포를 형성하게 된다. 발포제는 금속분말이 알칼리 용액과 접촉하여 수소가스를 발생시키는 원리를 이용하는 것으로써 현재 Autoclaved Light-Weight Concrete(ALC)의 제조에 사용되고 있다. 이와 같이 경량기포콘크리트 제조에 사용되는 기포제 및 발포제는 특성이 각기 다르기 때문에 내부 공극이 변화되고 이에 따라 경량기포콘크리트의 물리적, 단열특성이 변화될 것으로 예상된다. 따라서 본 연구에서는 기포제와 발포제를 사용한 경량기포콘크리트를 샌드위치 패널의 내부 단열재로 활용하는 기초적자료를 제공하기 위한 실험적 연구를 수행하였다. 즉, 경량기포콘크리트를 제조하는데 가장 일반적으로 사용하고 있는 기포제 및 발포제를 대상으로 하여 각각의 첨가량에 따른 경량기포콘크리트의 기포구조 및 열적특성을 검토함으로써 경량기포콘크리트의 높은 단열성능을 확보하기 위한 최적조건을 제시하기 위한 실험 실증적 연구를 수행하였다.

• 한국식품조리과학회지
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• 제7권2호
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• pp.97-104
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• 1991

This study was carried out in order to study the protein functionality such as foaming and emulsifying properties by succinylation of peanut protein isolates. Succinylated and unsuccinylated peanut protein isolate was tested for to find out the effect of pH, heat treatment and sodium chloride concentration on the solubility, foam expansion, foam stability, emulsion capacity and emulsion stability. The results are summarized as follows; 1. Succinylation enhanced the solubility of peanut protein isotate (PPI). The solubility of succinylated PPI markedly increased at pH 4.5. When the protein solutions was heated, the solubility of succinylated PPI greatly increased than PPI at pH 3. With addition of NaCl, solubility of succinylated PPI increased at pH 7 and pH 9. 2. The foam expansion of PPI and succinylated PPI on pH was no difference between both proteins. Addition of NaCl and heat treatment caused steeply increased in foam expansion at pH 3. 3. The foam stability of PPI and succinylated PPI showed the lowest value at pH 4.5. When PPI and succinylated PPI was heated, foam stability of two proteins incensed at pH 3 and showed similar aspects between PPI and succinylated PPI. However, at pH 9 stability of succinylated PPI decreased by heat treatment over $60^{\circ}C$. 4. Emulsion capacity of succinylated PPI on pH was markedly increased and showed the highest value at pH 11. At pH 4.5 which is isoelectric point of PPI, emulsion capacity of PPI by succinylation improved than that of PPI. When succinylated PPI was heated, emulsion capacity was greatly increased at pH 2 and pH 7. With NaCl was added, emulsion capacity of succinylated PPI increased than that of PPI. 5. Emulsion stability of PPI and succinylated PPI was affected by pH and showed its highest value at pH 11. At pH 4.5, emulsion stability of succinylated PPI increased than that of PPI. Addition of NaCl and heat treatment caused slightly increased in emulsion stability of succinylated PPI.

• Preventive Nutrition and Food Science
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• 제20권4호
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• pp.284-291
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• 2015

In this study, we attempted to enrich cyclo-His-Pro (CHP) using enzymatic hydrolysis of yeast and to evaluate the functionality of yeast hydrolysate (YH)-enriched CHP. Flavourzyme offered a better performance in enhancing CHP content than other proteases. The CHP enrichment conditions were optimized as follows: addition of 1% Flavourzyme, 48-h incubation at 60oC, and pH 6.0. The CHP content significantly increased by 20-fold after ultra-filtration (UF). Maximal CHP translation was obtained after heating for 8 h at 50oC and pH 7.0. YH showed poor foaming capacity between pH 3.0 to 9.0. The emulsifying activities of YHs were slightly higher at near acidic pH. Increase in heating temperature and time resulted in decreased CHP content. The results indicate that YH is more heat stable after UF. Therefore, the CHP in YH after UF can be used as a food additive with physiological CHP activity and high heat stability.

• 동아시아식생활학회지
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• 제18권1호
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• pp.1-8
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• 2008

In this study the rheological properties of Jeung-pyun prepared with soybean protein isolate (SPI) were investigated. SPI Jeung-pyun samples were manufactured with 3% whole protein, 7S protein, or 11S protein (w/w). In terms of moisture content the Jeung-pyun samples prepared with soybean flour had greater moisture contents than the control group. With the addition of SPI water binding capacity solubility and swelling power increased. Dough pH decreased during the fermentation, but increased after steaming and the SPI Jeung-pyun samples presented higher pH levels han the control group. Foaming ability was significantly strong in the 7S, 11S and whole protein groups. The surface structures of the 7S, 11S and whole protein Jeung-pyun samples displayed small uniform pores when examined by SEM. Overall, the results suggest that SPI can contribute to quality improvements in Jeung-pyun through effects on dough fermentation.

• 한국수산과학회지
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• 제51권4호
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• pp.351-361
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• 2018

This study investigated the potential of collagenous protein fractions (CPFs) as functional foods. The specific CPFs studied were recovered from the roe of bastard halibut (BH), Paralichthys olivaceus; skipjack tuna (ST), Katsuwonus pelamis; and yellowfin tuna (YT), Thunnus albacares through the alkaline solubilization process at pH 11 and 12. The buffer capacity, water-holding capacity and solubility of CPFs with pH-shift treatment were significantly better at alkaline pH (10-12) than at acidic pH (2.0). At pH-shift treatment (pH 2 and 12), the foaming capacities of CPFs from ST and YT were improved compared to those of controls, but they were unstable compared to BH CPFs. The emulsifying activity index (EAI, $m^2/g$ protein) of CPFs (controls) was 16.0-21.1 for BH, 20.1-23.9 for ST and 9.3-13.7 for YT (P<0.05). CPFs adjusted to pH 12 showed improved EAI and YT CPFs showed significantly greater emulsifying ability than those from BH and ST. CPFs recovered from fish roe are not only protein sources but also have a wide range of food functionalities, confirming the high availability of fish sausage and surimi-based products as protein or reinforcing materials for functional foods and alternative raw materials.

• 한국식품과학회지
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• 제18권3호
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• pp.204-209
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• 1986

번데기 단백질의 이용성을 증진시킬 목적으로 농축 단백질을 조제하여 중요한 성질인 기능성을 대두 단백질과 비교하였다. 번데기 농축단백질은 대두 농축단백질보다 지방 흡수력이 더 높았으며, 용해도와 수분 흡수력은 낮았다. 유화성은 62.8%로 번데기 농축단백질이 더 높았으며, 유화력도 307ml/g으로 역시 높게 나타났다. 또한 $80^{\circ}C$로 가열한 후의 유화안정성도 번데기 농축단백질이 65.8%로 대두 농축단백질보다 더 높게 나타났다. 포말성은 번데기 농축단백질이 더 낮았으며 포말안정성은 달걀알부민보다, 번데기, 대두 농축단백질이 더 낮았고, $5{\sim}7%$사이에 점도 증가 현상이 크게 나타났다. 이상의 실험결과에서 나타난 번데기 농축단백질의 높은 지방 흡수력과 유화성은 유화력을 이용한 식품제조에 좋은 단백질원으로서 이용이 가능하리라고 사료된다.

• 한국축산식품학회지
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• 제39권4호
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• pp.643-654
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• 2019

The amino acid composition, protein quality, and protein functionality of protein solution extracted from three edible insect species were investigated. We used 0.02% ascorbic acid and 0.58 M saline solution to extract water-soluble and salt-soluble proteins from the three insect species. Extracted protein solutions of Tenebrio molitor (TM), Allomyrina dichotoma (AD), and Protaetia brevitarsis seulensis (PB) were divided into six groups, according to species and solubility: WTM, WAD, WPB (water-soluble), and STM, SAD, and SPB (salt-soluble). Defatted TM had the highest protein content, but its protein solubility was the lowest, for both water and saline solutions. Amino acid composition differed by edible insect species and buffer type; SPB had the highest protein quality, followed by WPB. PB had a higher pH than the other species. Color values also differed among species. SPB had abundant high molecular weight proteins, compared with other treatments; and also had the highest foaming capacity, foam stability, and emulsifying capacity. In conclusion, PB is a good source of functional protein compared with the other studied species. Additionally, protein extraction using saline solution is promising as a useful method for improving edible insect protein functionality.

• 한국축산식품학회지
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• 제41권2호
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• pp.185-195
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• 2021

The objective of this study was to determine the effects of high pressure to investigate the technical functional properties of the protein solution extracted from an edible insect, Protaetia brevitarsis seulensis. High pressure processing was performed at 0 (control), 100, 200, 300, 400, and 500 MPa at 35℃. The essential amino acid index of the control was lower (p<0.05) than that of the P. brevitarsis seulensis extract treated with 100 MPa. The SDS-PAGE patterns tended to become faint at approximately 75 kDa and thicker at approximately 37 KDa after high pressure treatment. The protein solubility and pH of the protein tended to increase as the hydrostatic pressure levels increased. The instrument color values (redness and yellowness) of the P. brevitarsis seulensis protein treated with high pressure were lower (p<0.05) than those of the control. The forming capacity of the protein solution with P. brevitarsis seulensis treated with high pressure was higher (p<0.05) than that of the control. In conclusion, we confirmed that the technical functional properties of edible insect proteins extracted under high pressure of 200 MPa are improved. Our results indicate that high pressure can improve the technical functional properties of proteins from edible insects.

• 한국식품영양과학회지
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• 제17권4호
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• pp.312-319
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• 1988

정어리 단백질의 가수분해물로 합성한 plastein을 새로운 식품소재로서 고도이용 가능성을 구명하기위해 그의 기능성을 FPC 및 egg albumin과 비교검토하였으며, 아울러 소화율과 소화액의 관능검사도 실시하였다. 용해도는 plastein 제품이 FPC 보다 높았으며 glu-papain plastein은 pH변화에 관계없이 용해도가 84%로 높았으나 leu-papain plastein은 용해도가 매우 낮았다. 분산성은 plastein 제품이 egg albumin의 분산성에 비해 낮았으나 FPC보다는 월등히 높았다. Glu-papain plastein이 70.8%로 분산성이 가장 높았으나 pepsin plastin은 58.0%로 가장 낮았다. 보수력은 plastein제품이 FPC보다 약간 낮았으나 egg albumin보다 높았다. 지방흡수력은 leu-papain plastein이 2.2m1/ g 로서 가장 높았으나 glu-papain plastein이 1.6m1/ g 로 가장 낮았다. 유화성은 leu-papain plastein이 66.4%로 가장 높았으나 glu-papain plastein 51.2%로 가장 낮았다. 유화안정성도 이와 비슷한 경향이었다,. 포말성은 leu-papain plastein이 460%로서 egg albumin보다 4.6배 이상이었으며, 다른 plastein도 FPC보다 월등히 높았다. 포말안정성도 plastein이 egg albumin보다 좋았다. 점도는 glu-papain plastein을 제외한 plastein이 egg albumin에 비해 낮았다. In Vitro소화율은 $68.4{\sim}78.0%$였으며 glu-papain plasteul의 경우, molsin과 pretense같은 미생물 효소에 의한 plastein 소화액은 감칠맛이 매우 강하여 맛 강화제로서 이용이 가능할 것으로 판단되었다.