• Journal of Applied Biological Chemistry
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• 제42권3호
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• pp.125-129
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• 1999

The changes in gel characteristics of soy protein and succinylated soy protein due to various specific interaction-altering reagents which affect the formation and textural properties of gels, were studied. The reagents were added to 15% soy protein solutions prior to heat treatment. Succinylated soy protein formed harder gel without the addition of reagents. Hardly no gels were formed with urea, indicating that hydrogen bonds significantly contributed to the formation and hardness of the gel and the effects of urea on the hardness of succinylated soy protein gel were more significant. Disulfide bonds were important in the formation of hard gels whether they were succinylated or not, but the contributions of hydrophobic interactions to gel hardness were relatively insignificant. The hardness reducing effects of NaCl and NaSCN were more significant in succinylated soy protein gel. As such, electrostatic interactions were important for succinylated soy protein to form hard gel but not for unmodified soy protein.

• 한국축산식품학회지
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• 제43권6호
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• pp.1031-1043
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• 2023

The purpose of this study was to investigate the functional properties of salt-soluble proteins obtained from Protaetia brevitarsis (PB) and Tenebrio molitor (TM) larvae, the interaction between these proteins and pork myofibrillar protein (MP) in a gel system. The gel properties of salt-soluble protein extracts showed that the PB had a higher viscosity than the TM protein. However, the TM protein had higher gel strength compared with the PB protein. The gelation characteristics of the pork MP gel systems added with lyophilized insect salt-soluble protein powder showed to decrease slightly viscosity compared with MP alone. Adding the TM or PB protein powder did not affect the pork MP's hydrophobicity and sulfhydryl group levels. Furthermore, the protein bands of the MP did not change with the type or amount of insect salt-soluble protein. The cooking yields of the pork MP gels containing PB or TM protein powder were higher than those without insect protein. Regardless of the type of insect salt-soluble protein added, the pork MP's gel strength decreased. Furthermore, as the level of insect powder increased, the surface protein structure became rough and porous. The results demonstrated that proteins extracted from PB and TM larvae interfered with the gelation of pork MP in a gel system.

• 한국식품저장유통학회지
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• 제5권1호
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• pp.65-71
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• 1998

The changes in gel characteristics of soy protein as a result of various reagents that alter specific interactions which affect the formation and textural properties of gels, were studied. The reagents were added to 15% soy protein solutions prior to heat treatment. The gels were not formed with urea, indicating that hydrogen bonds significantly contributed to the formation and hardness of soy protein gel. Hydrophobic interactions and disulfide bonds compensated for hydrogen bonds and the contributions of electrostatic interactions to gel hardness are relatively insignificant. The farce primarily responsible for gel cohesiveness appeared to be disulfide bonds, because a significant decrease in cohesiveness was found only with the presence of N-ethylmaleimide. Adhesiveness decreased only with the addition of urea, and thus the contribution of hydrogen bonding to adhesiveness of gel could be concluded to be resent. However, adhesiveness was suggested to be interpreted not only wile molecular forces involved in gel formation but also with hydration properties of protein.

• 한국식품과학회지
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• 제23권4호
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• pp.428-432
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• 1991

본 연구는 식품산업 특히 육가공산업에 돈혈액의 이용을 위하여 NaCl, pH, phosphate가 혈장단백질과 근원섬유단백질 혼합물의 기능성에 어떠한 영향을 미치는지를 규명하고자 실시하였다. 각 단백질의 용해성은 NaCl 농도($1{\sim}4%$)와 $pH(4{\sim}8)$가 증가함에 따라 증가하였다. 혼합물(plasma+myofibrillar)의 용해성, 유화활성, 유화력은 혈장단백질 보다는 낮았으나 근원섬유단백질 보다는 높았다. 혼합물과 근원섬유단백질은 NaCl 농도가 2%에서 3%로 증가할 때 gel 강도가 현저히 증가하였다. 0.3%, polyphosphate를 첨가시 근원섬유단백질의 gel 강도는 약 4배 증가하였으며, 근원섬유단백질과 혼합물의 수분손실량이 크게 감소하였다. $3{\sim}5%$ 단백질농도에서 각 단백질의 gel 강도는 서서히 증가하였으나 $5{\sim}9%$에서는 단백질농도가 증가함에 따라 gel 강도가 크게 증가하였다.

• 한국식품과학회지
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• 제2권2호
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• pp.49-55
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• 1970

대두단백육(textured soybean protein food)의 제조 과정에서 분리한 대두단백의 건조공정은 단백 gel의 성질과 보수력, 점성도 같은 단백질 특성에 영향을 미쳤다. 모델시스템의 실험에서 질소용해계수로 표시한 대두단백의 변성도는 분리대두단백 gel의 강도의 중요한 변수로 나타났다. gel strength는 질소용해계수가 43이었을 때 최대가 되었고 질소 용해계수가 그보다 증가할 때나 감소할 때는 gel strength가 감소되었다. 이러한 사실은 분리대두단백의 건조공정 중 적당한 단백의 변성은 단백육제조에 필요하며 그 이상의 높은 질소용해계수를 갖도록 할 필요는 없다.

• 약학회지
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• 제35권6호
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• pp.461-465
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• 1991

Silica-based gel filtration chromatography has been used to characterize molecular weight of proteins. However, the molecular weight measured by this method was distorted by protein-silica interactions like hydrophobic and electrostatic forces. Therefore, we characterized protein-silica interaction using two forms of phytochrome (124 kDa) having different hydrophobicity and surface charge. PH and ionic strength affected the retention time of phytochrome suggesting that electrostatic force is the major interaction between protein and silica surface.

• 한국식품과학회지
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• 제25권3호
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• pp.295-298
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• 1993

식품산업 특히 육가공산업에 돈혈액의 이용을 위하여 가열온도 가열시간 및 단백질 농도가 혈장단백질과 근원섬유단백질 혼합물의 gel 특성과 열안정성에 어떠한 영향을 미치는지를 규명하기 위하여 실시되었다. 혈장단백질과 혼합물(plasma+myofibrillar protein)의 용해성은 가열온도가 $70^{\circ}C$에서 $90^{\circ}C$로 증가함에 따라 크게 감소하였으며, 근원섬유단백질은 $40{\sim}60^{\circ}C$에서 용해성이 서서히 감소하였다. 또한 gel 강도와 혼탁도는 이 온도범위에서 크게 증가하였다. 가열온도 $75^{\circ}C$에서 가열시간이 경과함에 따라 혈장단백질과 혼합물의 용해성은 감소하였으나 gel 강도와 혼탁도는 증가하였다. 근원섬유단백질은 $75^{\circ}C$에서 가열시간이 경과함에도 용해성, 혼탁도, gel 강도의 변화가 거의 나타나지 않았다. 근원섬유단백질, 혈장단백질, 혼합물의 gel 강도는 단백질 농도가 5%에서 9%로 증가함에 따라 증가하였다.

• 한국응용곤충학회지
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• 제37권1호
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• pp.59-64
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• 1998

꿀벌부채명나방 종령유충의 whole body에서 gel filtration 방법으로 유약호르몬 결합 단백질을 분리, 정제하였다. 분리된 단백질은 column chromatography법과 전기영동법에 의해 등가성을 확인하였다. 이 결합단백질은 전기 영동법에 의해 32K, gel filtration 에 의해 28K의 상대적 분자량을 나타냈다. 또한, JH III에 대한 해리도는 3.9$\times$${10}^{-7}$M로 확인되었다.

• Journal of Applied Biological Chemistry
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• 제51권3호
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• pp.88-94
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• 2008

Three different protein extraction methods-phenol extraction, trichloroacetic acid (TCA) precipitation, and desalting/TCA precipitation-were compared to determine the optimal reproducible high resolution 2-dimensional (2-D) electrophoresis for each chungkugjang, doenjang, and kochujang samples. The soluble proteins from Chungkugjang extracted by phenol were separated with high reproducibility and resolution, and gained 1.75- to 3-fold more protein spots on 2-D gel than those from the other methods. On the contrary, the extracted proteins from doenjang and kochujang treated by desalting/TCA precipitation method showed about 1.5- to 3.3-fold more protein spots on 2-D gel. Using the established methods, the changes in the protein profiles of the fermented soy foods were monitored during the fermentation period by 2-DE. One of the major proteins in soy, $\beta$-conglycinin $\alpha$-subuint, and some proteins with unknown functions were localized on 2-D gel as the protease-resistant proteins throughout the fermentation period of doenjang. Changes in the protein profile monitored by the established methods can provide basic information on unfolding the mechanisms of the generation of biofunctional activity in the fermented soy foods.

• 한국식품조리과학회지
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• 제12권4호
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• pp.571-576
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• 1996

The moisture-dependent gelation characteristics of five different proteins are evaluated to understand the modification of gel strength when they are added in surimi gel. Compressive force and penetration force of protein gels gradually decreased with increase of moisture level, with showing markedly decrease at certain point of moisture level called critical moisture level. The critical moisture level for gelation of SPI-1, SPI-2, EW, WPC and LA were 79.4%, 81.6%, 91.4％, 87,8% and 84.7%, respectively. Beyond this critical level of water, protein gel matrix begins to lose its water binding and structural integrity. The mnisture that was not re tained by a protein was available to diluting the protein matrix and eventually weakened the overall gel strength. EW and MPI showed higher water retention than those of SPI, WPC and LA. The compressive force of SPI, WPC and LA-incorporated surimi gel at the varying moisture levels strongly correlated with the amount if water retained at corresponding moisture level within those protein (r=0.99).