• 한국작물학회지
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• 제51권2호
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• pp.154-162
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• 2006

Cheese analogs using lipoxygenase-defected soymilk and ${\alpha}$-chymotrypsin modified soy protein isolate (SPI) were prepared. Color, textural properties, sensory attributes and melting spreadability of cheese analogs were evaluated and compared with mozzarella cheese, and relationships between textural properties, sensory attributes and melting spreadability of cheese analogs were analyzed. Off-flavors were not mostly discriminated. Cheese analogs containing 10% SPI untreated and containing 6% and 8% SPI treated by ${\alpha}$-chymotrypsin in ${\Delta}E$ value of color were the most similar to mozzarella cheese. Quality characteristics and melting spreadability of cheese analogs were highly affected and improved by ${\alpha}$-chymotrypsin modification. Sensory attributes and melting spreadability of cheese analogs containing 6% SPI treated by ${\alpha}$-chymotrypsin were the most similar to mozzarella cheese, while in textural properties, cheese analogs containing 10% SPI were the most similar with mozzarella cheese. Hardness in sensory attributes was highly positively correlated with hardness (r>0.65), adhesiveness (r>0.56), chewiness (r>0.77) and gumminess (r>0.76) in textural properties, while it was highly negatively correlated with melting spreadability (r>-0.68).

• 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.

• Asian-Australasian Journal of Animal Sciences
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• 제30권8호
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• pp.1135-1142
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• 2017

Objective: The objective of this study was to evaluate effects of heat treatment and soybean oil inclusion on protein oxidation of soy protein isolate (SPI) and of oxidized protein on redox status of broilers at an early age. Methods: SPI mixed with soybean oil (SPIO) heated at $100^{\circ}C$ for 8 h was used to evaluate protein oxidation of SPI. A total of two hundred and sixteen 1-day-old Arbor Acres chicks were divided into 3 groups with 6 replicates of 12 birds, receiving basal diet (CON), heat-oxidized SPI diet (HSPI) or mixture of SPI and 2% soybean oil diet (HSPIO) for 21 d, respectively. Results: Increased protein carbonyl, decreased protein sulfhydryl of SPI were observed as heating time increased in all treatments (p<0.05). Addition of 2% soybean oil increased protein carbonyl of SPI at 8 h heating (p<0.05). Dietary HSPI and HSPIO decreased the average daily gain of broilers as compared with the CON (p<0.05). Broilers fed HSPI and HSPIO exhibited decreased glutathione (GSH) in serum, catalase activity and total sulfhydryl in liver and increased malondialdehyde (MDA) and protein carbonyl in serum, advanced oxidation protein products (AOPPs) in liver and protein carbonyl in jejunal mucosa as compared with that of the CON (p<0.05). Additionally, broilers receiving HSPIO showed decreased glutathione peroxidase activity (GSH-Px) in serum, GSH and hydroxyl radical scavenging capacity in liver, GSH-Px activity in duodenal mucosa, GSH-Px activity and superoxide anion radical scavenging capacity in jejunal mucosa and increased AOPPs in serum, MDA and protein carbonyl in liver, MDA and AOPPs in jejunal mucosa (p<0.05). Conclusion: Protein oxidation of SPI can be induced by heat and soybean oil and oxidized protein resulted in redox imbalance in broilers at an early age.

• 한국식품과학회지
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• 제9권3호
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• pp.190-193
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• 1977

동방유량(東邦油糧)에서 저변성탈지대두박(低變性脫脂大豆粕)을 공급받아 Soy Protein Isolates(SPI)를 제조(製造)하여 이의 식품학적(食品學的) 특성(特性)을 연구(硏究)한바 있다(Korean J. Food Sci., 9, 123(1977)). 이 SPI의 실제응용성(實際應用性)을 검토(檢討)하고자 12% SPI액(液)을 가열(加熱) gel화(化)시켜 풍건 마쇄한 SPI를 beef patties의 증량제(增量劑)로 사용하였을 때, SPI gel로 30% meat를 대체하여도 관능검사(官能檢査) 결과(結果) 유의성(有意性) 있는 차이(差異)를 나타내지 않았다. 또한 cooking loss도 13.5%(대조구(對照區))에서 2%로 현저히 줄었다. SPI를 milk-Solid-Not-fat(MSNF)와 대체하여 제조한 아이스크림은 관능검사결과(官能檢査結果) texture는 대조구(對照區)과 차이(差異)가 없었으나 향미면(香味面)에서 콩비린내 때문에 전체적(全體的) 품질(品質)이 크게 떨어졌다. 이것은 아이스크림이 향미(香味)가 전체품질(全體品質)에 큰영향을 갖는 그 자체의 특성때문인 것으로 간주된다. 탈지대두박(脫脂大豆粕)에서 추출(抽出)한 분리대두단백(分離大豆蛋白)은 콩비린내 문제만 해결(解決)되면 우수한 식품학적(食品學的) 특성(特性)때문에 동물성(動物性) 단백질(蛋白質)과 대체하여 식품제조시(食品製造時) 첨가제(添加劑)로서 사용이 가능(可能)함을 알았다.

• 한국식품조리과학회지
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• 제15권1호
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• pp.73-80
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• 1999

This study was carried out to investigate the effects of enzyme treatments on the functional properties of soy protein isolate (SPI) and to examine the quality attributes of soy yogurt prepared by different enzyme treatments, sweeteners and starter cultures. Enzyme treatment increased the solubility and emulsifying capacity of soy proteins, but decreased the emulsifying stability; the enzymatic activity of ${\alpha}$-chymotrypsin was higher than that of trypsin. Enzyme treatments decreased the pH of soy yogurts prepared by both culture methods, the culture of L. bulgaricus and S. thermophilus and the culture of L. bulgaricus and K. fragilis, but increased the titratable acidity, total numbers of lactic acid bacteria and yeast. Trypsin was more effective than ${\alpha}$-chymotrypsin in decreasing pH and increasing titratable acidity and total numbers of lactic acid bacteria and yeast. Fructose decreased the pH of soy yogurts more than sucrose in the culture of L. bulgaricus and S. thermophilus, and vice versa in the culture of L. bulgaricus and K. fragilis. Fructooligosaccharides were more effective in the culture of L. bulgaricus and K. fragilis than in the culture of L. bulgaricus and S. thermophilus in increasing the titratable acidity, total count of lactic acid bacteria and yeast. In sensory evaluation, soy yogurts containing trypsin treated SPI, fructose and fructooligosaccharides (75%:25%) were more acceptable than those containing untreated or trypsin treated SPI and fructose. This was because of more smooth and less sour, in which the values of pH, titratable acidity, microbial growth, and viscosity were in the range of commercial yogurts. Soy yogurts fermented by L. bulgaricus and K. fragilis showed more smooth mouthfeel than those fermented by L. bulgaricus and S. thermophilus.

• 한국식품과학회지
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• 제38권4호
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• pp.534-542
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• 2006

본 연구는 아이소플라본 등 여러 생리활성 물질을 가지고 있는 콩 단백질의 섭취를 증가시키기 위하여 분리 콩단백(soy protein isolate)을 첨가한 복합분의 이화학적 특성, rheology특성, 제품적성 등을 검토하였다. 공시된 시료의 단백질 함량은 분리 콩단백이 83.5%로서 박력분보다 9.8배 높았다. 박력분에 분리 콩단백을 3-24% 첨가하였을 때, 단백질 함량은 28.5% 증가하였으며, 침전가는 13.5 mL 감소하였다. 알칼리수 흡수능은 분리 콩단백의 첨가량이 증가함에 따라 증가하는 경향을 보였으며, 알칼리수 흡수능과 단백질 함량과는 고도의 정의 상관이, 그리고 침전가와는 부의 상관이 있었다. Rapid visco analyser(RVA)에 의한 호화특성을 보면, initial pasting temperature는 분리 콩단백 첨가구의 경우 $74.8-84.4^{\circ}C$로서 분리 콩단백 첨가량이 증가함에 따라 증가되었다. 반면에 최대, 최소 및 최종점도는 분리 콩단백의 첨가량이 증가함에 따라서 현저하게 감소되었다. RVA 특성과 단백질 함량, 침전가, 알칼리수 흡수능과는 고도의 정 또는 부의 상관이 있었다. 분리 콩단백의 첨가량에 따른 mixograph 특성을 보면, 분리 콩단백 첨가의 정우 peak 시간은 18% 첨가 시부터, peak 높이는 21% 첨가 시부터 유의적인 차이가 있었다. White layer cake batter의 pH와 비중은 분리 콩단백 첨가량이 증가함에 따라 다소 증가하는 경향을 보였다. White layer cake의 부피와 비용적은 분리 콩단백의 첨가량이 증가함에 따라 감소하는 경향을 보였으나 그 변화폭은 크지 않았다. White layer cake의 부피지수는 분리 콩단백의 첨가량이 증가함에 따라서 감소하였으며, 대칭지수도 분리 콩단백을 첨가함으로써 감소하는 경향을 보였다. Mixograph peak 시간과 케이크의 부피와는 정의 상관$(r=0.738^{**})$이 없었다. Cake crust $L^*$값은 분리 콩단백 첨가군이 57.7-51.4로서 분리 콩단백 첨가량이 증가함에 따라서 감소하는 경향을 보였으며, $a^*$값과 $b^*$값은 분리 콩단백의 첨가량이 증가함에 따라 증가하였다. White layer cake의 관능검사 결과 케이크 제조 시 분리 콩단백의 첨가량은 9%가 가능할 것으로 사료되며, 케이크의 전체적인 기호도와 케이크의 부피와는 고도의 정의 상관이 있었다. 케이크의 경도는 분리 콩단백 첨가량이 증가함에 따라서 증가하였다.

• 한국식품과학회지
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• 제23권3호
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• pp.286-290
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• 1991

대두의 영양 저해인자로 알려진 phytic acid를 pH를 조절하는 각기 다른 방법으로 제거할 low-phytate soy protein isolate(SPI)와 high-phytate SPI를 얻어 이들 분리 대두단백의 용해도와 소화율에 미치는 phytic acid 함량의 영향을 조사하였다. 분리 대두단백의 phytic acid 함량은 high-phytate SPI에서 2.48%이었고, low-phytate SPI에서는 0.72%이었다. 분리 대두단백의 용해도는 모든 pH에서 low-phytate SPI가 high-phytate SPI 보다 높았으며 phytic acid의 첨가량이 많을수록 용해도가 떨어져 침전되었다. 분리 대두단백의 소화율에 미치는 phytic acid의 저해적 영향은 phytic acid 첨가량이 증가할수록 더 컸으며, low-phytate SPI 보다 high-phytate SPI에서 그 저해효과가 약간 크게 나타났다.

• 한국식품과학회지
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• 제17권5호
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• pp.383-388
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• 1985

분리대두단백질을 succinic anhydride 및 acetic an-hydride와 반응시켜 화학적으로 변형시켜 기능성을 조사한 결과, 대두단백질의 등전점이 pH4.5에서 4.0으로 내려가면서 등전점이상의 영역. 특히 PH4.0-6.0영역에서 용해도가 크게 증가하였다. $Ca^{2+}$이 존재할 때 용해도는 변형시킨 경우 분리대두단백질에 비하여 4배 이상으로 증가하였다. 유화특성 및 기포특성 또한 크게 향상되는 결과를 보였다. 대두단백질의 고유점도를 측정한 결과 변형에 의하여 전반적으로 증가하였으며 희석용액으로부터 추정되는 입자간의 interaction coefficient는 감소하였다.

• Journal of Applied Biological Chemistry
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• 제55권1호
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• pp.27-34
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• 2012

Soy protein isolate (SPI)-based edible coating, with and without carboxymethyl cellulose (CMC), were used to reduce oxidative degradation of cut pork stored at $4^{\circ}C$ for 5 days. The SPI coating reduced (p<0.05) thiobarbituric acid-reactive substances (TBARS) and peroxide value (PV), compared with controls. The inhibition of TBARS and PV for SPI-coated porks with and without CMC, compared with the control was 19.1 and 23.9, and 25.7 and 37.7%, respectively. The SPI coating prevented loss of $L^*$ and $a^*$ values of porks compared to the control. The ability of the SPI coating to provide a moisture barrier for the porks was reduced (p<0.05). The SPI-coated porks with and without CMC reduced moisture loss by 37.3 and 44.6%, respectively, over the control. However, SPI coating of porks did not inhibit the growth of either total plate counts or L. monocytogenes. The result revealed that SPI can effectively be used as a natural antioxidative coating to extend quality and shelf life of pork.

• 한국식품영양학회지
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• 제7권3호
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• pp.177-182
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• 1994

The effect of phosphate salt (NafHP04) and sodium citrate on the emulsion stability of soy protein isolate (SPI) in the presence of calcium was investigated in terms of salt concentration and addition order. Both phosphate and citrate salts decreased the solubility of SPI despite their pH enhancing effects. Addition of calcium chloride (CaCl2) significantly decreased ES, which showed nearly negligible at more than 3 mM CaCl2 concentration. When Na2HP04 were added in the presence of 5 mM Cac12, 55 greatly increased up to 20mM concentration, above which however ES decreased. It was found that the addition order of Na2HPO4 and CaCl2 affected ES. The addition of phosphate and subsequent CaCl2 exhibited the higher 55 than the reverse order. In both cases, the overall ES profile was found to be nearly similar to the solubility profile of SPI, indicating the positive relationship between solubility and emulsion stability of SPI in the presence of calcium. Similar trend to the phosphate effect on ES was also observed for sodium citrate in the presence of calcium.