• 한국식품과학회지
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• 제31권6호
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• pp.1488-1494
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• 1999

감마선 조사가 상업적 등급의 SPI와 WPC의 SDS-PAGE 헝태와 이차구조 함량, 용해도 등 이화학적 변화에 미치는 영향을 조사하였다. 감마선이 조사된 SPI와 WPC의 SDS-PAGE 형태은 SPI 용액의 경우 5 kGy 이상 조사에서 단백질의 degraded pattern과 아울러 중합이 나타난 반면에 WPC 용액에서는 단백질이 절단된 형태로 나타났다. 반면에 감마선이 조사된 SPI와 WPC 분말의 경우 분자량 분포에는 큰 변화가 없었다. Circular dichroism 연구에서 감마선이 조사된 SPI와 WPC용액의 이차구조의 변화는 감마선 조사에 의하여 단백질의 구조 변화를 나타내는 random coil함량이 증가하였다. 또한, SPI와 WPC 분말의 경우에는 감마선 조사에 의한 용해도의 차이가 있었다.

• 한국작물학회지
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• 제51권2호
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• pp.148-153
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• 2006

Effects of ${\alpha}$-chymotrypsin modification on degree of hydrolysis (DH), solubility, emulsifying capacity and thermal aggregation of laboratory-purified soy protein isolate (SPI) using a lipoxygenase-defected soybean (Jinpum-kong) and commercial soy protein isolate (Supro 500E) were compared. SPIs were hydrolyzed by ${\alpha}$-chymotrypsin at pH 7.8 and $37^{\circ}C$ for 30 min. DHs of Supro 500E and Jinpum-kong SPI were increased by ${\alpha}$-chymotrypsin modification, and DH of Supro 500E was higher than that of Jinpum-kong SPI. DH of ${\alpha}$-chymotrypsin treated Jinpum-kong SPI was similar with untreated Supro 500E and DH of treated Supro 500E was the highest. Solubility, emulsifying capacity and thermal aggregation of SPIs were increased by ${\alpha}$-chymotrypsin modification, and these changes were highly related to changes in DH. Functional properties of Supro 500E were higher than Jinpum-kong SPI in both of untreated and ${\alpha}$-chymotrypsin treated SPIs.

• Food Science and Biotechnology
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• 제15권4호
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• pp.631-634
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• 2006

Soy protein isolate (SPI) films were supplemented with cinnamaldehyde (CA) at concentrations of 0.1-0.5 mL/5 g SPI. The effects of CA on film color, tensile strength (TS), percent elongation at break (E, %) and water vapor permeability (WVP) of SPI films were investigated. Generally, total color difference (${\Delta}E$), WVP, and TS of SPI films increased gradually, while E and TSM decreased significantly (p<0.05) as the amount of cinnamaldehyde in the SPI films increased. Cinnamaldehyde can be used as a potential cross-linking agent for preparing SPI films by improving mechanical strength and water resistant properties.

• 한국식품저장유통학회지
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• 제8권2호
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• pp.181-186
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• 2001

The objective of this study is to determine the effect of soy protein isolate (SPI) film coating on the color, firmness, viscosity and weight loss of Rice Cake stored at 15, 20 and $25^{\circ}C$ (RH 50%) for 30 days. Raw materials mixed with SPI and cocoa powder (10:0, 7:3, 5:5, 3:7, w/w) were prepared. After adding sugar and shortening to raw materials, the mixture were refined to 25 micron of particle size. Coating of Rice Cake were carried out at $65^{\circ}C$. SPI coated Rice Cake had higher internal and external firmness comparing to the control at $25^{\circ}C$. SPI coated Rice Cake showed smooth surface morphology and had 0.71-1.01 mm of thickness. SPI coated Rice Cake showed less weight loss for 30 days compared to controls. SPI coating solution was successfully coated on Rice Cake and extended shelf-life over 15 days at room temperature.

• 한국식품영양과학회지
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• 제45권9호
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• pp.1285-1292
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• 2016

분리콩단백질(SPI, soy protein isolate) 농도, pH, 전해질의 종류와 농도, alginates의 농도와 분자량이 SPI의 표면소수성에 미치는 영향을 조사한 결과는 다음과 같다. SPI 농도가 증가할수록 표면소수성은 감소하였다. SPI의 표면소수성이 pH 7.0에서 최대값을 나타내었다가 pH가 7.0을 기준으로 증가 혹은 감소함에 따라 표면소수성이 감소하는 경향을 나타내었다. SPI의 표면소수성은 NaCl의 농도가 100 mM까지 증가함에 따라 급격히 증가하지만 더 이상의 농도에서는 변화가 없었다. $CaCl_2$와 $MgCl_2$의 농도가 각각 50 mM과 30 mM까지 증가할수록 SPI의 표면소수성이 급격히 감소하였지만, 그 이상의 농도에서는 큰 변화가 없었다. Na-alginate의 농도와 분자량의 증가함에 따라 SPI의 표면소수성이 감소한 것으로 나타났다. Na-alginate의 분자량이 증가함에 따라 표면소수성의 증가속도가 감소하였다.

• Preventive Nutrition and Food Science
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• 제21권4호
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• pp.338-347
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• 2016

The present study investigated the volatile compound, physicochemical, and antioxidant properties of beany flavor-removed soy protein isolate (SPI) hydrolyzates produced by combined high temperature pre-treatment and enzymatic hydrolysis. Without remarkable changes in amino acid composition, reductions of residual lipoxygenase activity and beany flavor-causing volatile compounds such as hexanol, hexanal, and pentanol in SPI were observed after combined heating and enzymatic treatments. The degree of hydrolysis, emulsion capacity and stability, 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity, and superoxide radical scavenging activity of SPI were significantly increased, but the magnitudes of apparent viscosity, consistency index, and dynamic moduli (G', G") of SPI were significantly decreased after the combined heating and enzymatic treatments. Based on these results, it was suggested that the enzymatic hydrolysis in combination with high temperature pre-treatment may allow for the production of beany flavor-removed SPI hydrolyzates with superior emulsifying and antioxidant functionalities.

• 한국식품영양과학회지
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• 제35권9호
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• pp.1251-1255
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• 2006

대두단백 필름을 코팅한 라이너지의 효과를 알아보기 위하여 대두단백 $2\sim8%$의 농도 범위에서 필름을 제조하였다. 필름 제조시 친수성 소재인 대두단백의 불용화를 위하여 모든 필름은 formaldehyde로 포화된 데시케이터에서 2시간 동안 흡착하여 사용하였다. 필름의 연신강도, 연신율, 투습도 및 수분용해도를 측정한 뒤 최적 농도를 5%로 판단하였다. 필름의 제조적성을 위해 첨가된 가소제 glycerol은 대두단백 대비 40% 농도에서 필름제조에 가장 적합하였다. 앞의 조건을 이용하여 제조된 용액을 라이너지에 코팅하여 그 물성과 수분저항성을 측정하였다. Formaldehyde 처리된 대두단백 코팅 라이너지는 미처리 라이너지에 비하여 연신강도는 15 에서 21 MPa로 증가하였고, 수분용해도와 투습계수는 1.17%와 $2.06ng{\cdot}m/m^2{\cdot}s{\cdot}Pa$로 감소하여 물리적 성질과 수분저항성 모두 증진된 것을 알 수 있었다.

• Composites Research
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• 제27권5호
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• pp.196-200
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• 2014

A novel, simple and totally recyclable method has been developed for the synthesis of nontoxic, biocompatible and biodegradable bio-composite films from soy protein and silk protein. Bio films are defined as flexible films prepared from biological materials such as protein. These materials have potential application in medical and food as a packaging material. Their use depends on various parameters such as mechanical (strength and modulus), thermal, among others. In this study, prepare and characterization of bio films made from Soy Protein Isolate (SPI) (matrix) and Silk Fiber (SF) (reinforcement) through solution casting method by the addition of plasticizer and crosslinking agent. The obtained SPI and SPI/SF composites were subsequently subjected to evaluate their mechanical and thermal properties by using Universal Testing Machine and Thermal Gravimetric Analyzer respectively. The tensile testing showed significant improvements in strength with increasing amount of SF content and the % elongation at break of the composites of the SPI/SF was lower than that of the matrix. Though the interfacial bonding was moderate, the improvement in tensile strength and modulus was attributed to the higher tensile properties of the silk fiber.

• 대한가정학회지
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• 제28권4호
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• pp.41-50
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• 1990

Soy protein was isolated from Korean soy bean 'Chang ryub' and chemically modified with succinic anhydride. Functionality of the soy protein isolate(SPI), succinylated SPI(SPPI), and PP590(commercial) at various pH were investigated. The mechanical and sensory properties of soy bean curds made from several mixing ratio of succinylated soy bean milk were observed. The solubility of SPI significantly increased with succinylation. The solubility of PP590 was lower than that of SSPI. The solubility of SPPI increased significantly in 0.03M CaCl2 solution. The emulsifying activity of SSPI increased. On the range of pH above pI the emulsifying activity of PP590 was higher than that of SPI. There was no difference in emulsion stability among the groups. The foam expansion capacity of SPPI increased at higher pH than pI but the foam stability decreased significantly above pH 9. Mechanical texture profile analysis revealed the modified soy bean curds had the lower hardniss, chewiness and cohesiveness with increased modification. The mechanical characteristics of modified soy bean curds revealed generalized Maxwell Model of 7-elements or 5-elements. In sensory evaluation, the hardness, the springiness and acceptability of modified soy bean curds were lower significantly than those of control soy bean curd.

• Advances in materials Research
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• 제11권3호
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• pp.191-209
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• 2022

Very slow degradation of synthetic based polymers has created a severe environmental issue that increased awareness towards research in polymers of biodegradable property. Soy protein isolate (SPI) is a natural biopolymer used as matrix in green composites but it has limitations of low mechanical properties and high water sensitivity. To enhance mechanical properties and reduce water sensitivity of Jute-SPI composites, SPI was modified with pine rosin which is also a natural cross-linking agent. 30% glycerol on the weight basis of a matrix was used as a plasticizer. The fibre volume fraction was kept constant at 0.2 whereas the pine rosin in SPI ranged from 5% to 30% of the matrix. The effects of pine rosin on mechanical, thermal, water sensitivity and surface morphology have been characterized using various techniques. The mechanical properties and water absorbency were found to be optimum for 15% pine rosin in Jute-SPI composite. Therefore, Jute-SPI composite without pine rosin and with 15% pine rosin were chosen for investigation through characterization by Fourier transforms infrared spectroscopy (FTIR), Thermo-gravimetric analysis (TGA), X-Ray diffraction (XRD) and Scanning electron microscope (SEM). The surface morphology of the composite was influenced by pine rosin which is shown in the SEM image. TGA measurement showed that the thermal properties improved due to the addition of pine rosin. Antimicrobial test showed antimicrobial property in the composite occurring 15% pine rosin. The research paper concludes that the modification of SPI resin with an optimum percentage of pine rosin enhanced mechanical, thermal as well as water-resistant properties of jute fibre reinforced composites.