• Journal of Nutrition and Health
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• 제15권2호
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• pp.119-128
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• 1982

The effect of dietary protein on growth and lipid levels of plasma and liver was studied in weanling male rats fed diets differing protein sources and amino acid balance. Rats were devided into 9 experimental diets which were grouped into 3 categories ; 1) Simple protein category includes gluten-, soy protein isolate-, and casein-containing diet groups, 2) Supplemented category includes casein supplemented with methionine, soy protein isolate supplemented with methionine, and gluten supplemented with lysine and methionine, 3) Mixed protein category includes diet groups containing gluten (2/3), casein (1/3), soy protein isolate (2/3) and casein (1/3), and casein (1/3), soy protein isolate (1/3) and gluten (1/3). The experimental diets composed of 15% protein, 65.8% carbohydrate, 10% fat and 1% cholesterol. The body wt. gain and P.E.R. were greater in rats of supplemented and mixed protein groups than simple protein groups. No statistical differences were found in plasma cholesterol among gluten, soy protein isolate and casein groups. Consumption of diets supplemented with limiting amino acid to gluten or soy protein isolate reduced the plasma cholesterol level by 23.2% and 34.2% respectively. However there was no difference between casein and the supplemented casein groups. The mixed protein groups shows relatively high plasma cholesterol concentration and low liver cholesterol levels. On the other hand gluten group showed low plasma cholesterol and high liver cholesterol levels, which means body cholesterol pool may not have been changed by the dietary protein. Feeding soy protein meal and the supplemented soy protein isolate resulted in lower plasma cholesterol, plasma triglycerides, liver cholesterol and liver triglycerides levels. This hypolipidemic effect is considered to see unique to soy protein isolate. Rats in gluten and the supplemented gluten groups showed lower plasma protein levels and a tendency of fatty liver.

• 한국축산식품학회지
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• 제32권5호
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• pp.627-634
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• 2012

This study was carried out to investigate the physical and thermal properties of ${\kappa}$-carrageenan (${\kappa}$-car) gel added whey protein isolate (WPI) as a cryoprotectant. The concentration of ${\kappa}$-carrageenan was fixed at 0.2 wt%. The mean ice crystal size of the WPI/${\kappa}$-car was decreased according to increasing whey protein isolate concentration. The temperature of gel-sol (Tg-s) and sol-gel (Ts-g) transition of WPI/${\kappa}$-car maxtrix was represented in the order of 3.0, 0.2, 5.0 and 1.0 wt%. In addition, the transition temperature of gel-sol of WPI in sucrose solution were showed in order of 1.0, 5.0, 0.2 and 3.0 wt% depending on whey protein isolate concentration. The shape of ice crystal was divided largely into two types, round and rectangular form. 1.0 wt% WPI/${\kappa}$-car matrix at pH 7 and 9 showed minute and rectangular formation of ice crystals and whey protein isolate in sucrose solution at a concentration of 1.0 wt% WPI/${\kappa}$-car matrix at pH 3 and 5 showed relatively large size and round ice crystals. The ice recrystallization characteristics and cryprotective effect of ${\kappa}$-carrageenan changed through the addition of different concentrations of whey protein isolate. It seems that the conformational changes induced interactions between whey protein isolate and ${\kappa}$-carrageenan affected ice recrystallization.

• 한국식품영양과학회지
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• 제14권1호
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• pp.51-56
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• 1985

옛 부터 부수게 제조시 대두 slurry를 첨가하여온 의미와 최적 대두 첨가 형태 및 최적 첨가량을 규명하고자 대두 제품인 대두 slurry, soy protein isolate, soy protein concentrate, defatted soy flour, soy hot water extract를 첨가하여 부수게 바탕에 미치는 결과를 조사한 바 다음과 같이 요약 할 수 있다. 부수게 바탕은 저수분 ($4{\sim}5%$), 고지방($20{\sim}21%$)식품으로 대두 slurry를 첨가함으로써 단백질 강화와 품질 향상에 효과가 있으며 대두 제품중에서 대두 slurry는 용적 증가율, 경도, panel score에서 유리하였고 soy protein isolate는 단백질 강화를 위해서 가장 유리한 형태 이었다. 또한 이상적인 첨가 형태는 대두 slurry와 soy protein isolate를 병용하는 것이었고 이 경우 soy protein isolate의 첨가량은 10% 전후가 적당 하였다.

• 한국식품과학회지
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• 제24권3호
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• pp.279-283
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• 1992

식물성 식품중의 영양 저해 인자로 알려진 phytate를 제거한 분리 유채단백(low-phytate rapeseed protein isolate)을 제조하여 pH 및 phytate 첨가량이 이들 분리 유채단백의 용해성과 소화율에 미치는 영향을 살펴보았다. 분리 유채단백의 phytate 함량은 1.5%로서 탈지 유채분말보다 66%가 감소되었으며 protein : phytate ratio는 58 : 1이었다. 분리 유채단백의 용해도는 pH 2.0과 pH 11.5에서는 매우 높았으나 pH 5.0에서는 매우 낮았다. 그 용해도에 미치는 phytate 첨가량의 영향을 보면 pH 5.0과 pH 11.5에서는 별 차이가 없었으나 pH 2.0에서는 phytate 첨가량이 많을수록 그 용해도가 감소하였다. 분리 유채단백의 pepsin 소화율에 미치는 phytate의 저해적 영향은 phytate 함량이 증가할수록 더 커졌다. 소화기간 초기에는 그 영향이 매우 컸으나 소화시간이 길어짐에 따라 그 영향은 점점 감소되었으며 평균소화율은 24%가 감소하였다. 따라서 유채단백을 식품소재로 이용하기 위해서는 phytate 함량이 낮은 제품을 제조함으로써 그의 기능성과 영양가를 향상시킬 수 있을 것이다.

• 한국자원식물학회지
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• 제11권3호
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• pp.272-278
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• 1998

This study was carried out to investigate the functional properties such as nitrogen solubility, emulsifying property , foaming capapcity , water and oil absorption of Camellia (Camellia japonica .) seed protein isolate in condition of distilled water and 0.5M NaCl solution at pH 2.0∼10.0. Nitrogen solubility of Camellia protein isolate in distilled water showed the minimum value at pH 4.0 and increased at pH lower or higher than the isoelectric point(pH 4.0). It was 90.0 %at pH 10.0 Nitrogen solubility of 0.5M NaCl solution showed a similar pattern with that of distrille dwater but was higher than that of distilled water except pH 2.0 and pH 10.0. Emulsifying activity of Camellia seed protein islate showed the minimum value at pH 4.0, but was higher at ether value of pH. Emulsifying stability of protein isolate was stable by heat treatment for 30min, at 80℃ and increased in 0.5M NaCl solution more than that of distille dwater. Foaming capacity of Camellia seed protein isolate in distill3ed water showed the minimum value near the isoelectric point, While it changed little at other values of pH. Foaming stability slowly decreased as, but didn't make a significant difference as time was delayed . Oil absorption was 1.4ml per a sample of 1g and water absorption was 0.9ml per a sample of 1g. The former was higher than the latter . The content of total amino acid of Camellia protein isolate was 43.67% and the major total amino acid of Camellia protein isolate was 43.67% and the major total amino acid was in the order of glutamic acid , arginine, aspartic acid, and leucine.

• 한국식품과학회지
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• 제25권4호
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• pp.360-365
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• 1993

Phytate 함량이 다른 두 분리 대두단백(HSPI; high-phytate soy protein isolate, LSPI; low-phytate soy protein isolate)을 제조하여 pH 및 phytate 첨가량이 그들의 용해도와 소화율에 미치는 영향을 알아보았고 분리 대두단백을 용해도에 따라 분별한 후 그들의 특성을 전기영동을 통하여 알아보았다. LSPI와 HSPI 모두 분자량이 $13.6{\sim}81.1kDa$에 이르는 단백질 성분으로 이루어져 있으며 산성 pH에서 $18.0{\sim}35.0kDa$의 단백질은 phytate와 잘 결합하지 않는 특성을 가졌다. LSPI를 용해도에 다라 분별하였을 때 gliadin을 구성하는 단백질은 pH2에서 phytate와 쉽게 결합하지 않았다. 대두 단백질은 pepsin 소화율은 phytate 첨가량이 증가할수록 크게 저하되었다.

• 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 $100^{\circ}C$.

• 한국축산식품학회지
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• 제42권5호
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• pp.849-860
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• 2022

The myofibril protein (MP) isolate-saccharide graft reactions was prepared using the Maillard reaction with saccharides. The effects of various saccharides on protein functionality and quality of the Maillard reaction were investigated and compared with those of MP. The grafting degree of the MP isolate-saccharide graft reaction was significantly higher in the reducing sugar-treated groups (lactose, glucose, fructose, and palatinose). The browning intensity of the MP isolate-saccharide graft reaction with fructose, sucrose, and erythitol was higher than that observed in the control reaction (p<0.05). MP that reacted with reducing sugars (glucose, fructose, palatinose, and lactose) had fainter bands than MP that reacted with non-reducing sugars (sucrose, erythitol, trehalose, sorbitol, and xylitol). MPs conjugated with glucose exhibited higher protein solubility. The palatinose and lactose treatments were maximum in water binding capacity, though no significant difference in oil binding capacity among the saccharide treatments was observed. The emulsion stability of the MP isolate-saccharide graft reaction with palatinose and erythitol was higher than that of the control reaction. Therefore, reducing sugars have good protein functionality in the MP isolate-saccharides graft reaction.

• 한국식품과학회지
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• 제12권4호
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• pp.263-271
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• 1980

피마자박 단백질을 사료 또는 식품화 하기 위하여 탈지 피마자박으로부터 독성분이 완전하게 제거된 단백질을 만들었다. 이 피마자 단백질의 용해도는 ${\varepsilon}$-아미노기의 숙시닐화 및 아세틸화로 $pH\;7{\sim}8$에서 현저하게 증가하였다. 아미노산 분석결과, 황-함유 아미노산과 L-리신이 제한 아미노산이었고, 아실화 과정은 아미노산 함량에 약간의 손실을 주었다. 파파인을 이용한 1 단계법 plastein 반응으로 피마자 단백질 또는 아실화 피마자 단백질과 DL-메티오닌 에틸 에스테르로부터 L-메티오닌 강화 피마자 단백질을 합성하였고, 이 방법으로 L-메티오닌 도입율은 50%였다. 피마자 단백질 및 수식된 피마자 단백질의 펩신에 의한 소화율은 모두 92% 정도였으나, 트립신에 의한 소화율은 숙시닐화 및 아세틸화 단백질이 현저하게 떨어져서 각각 42% 및 26%였다. 피마자 단백질의 단백질 효율은 L-메티오닌 강화로 카제인의 단백질 효율의 90%까지 향상되었으나, 피마자 단백질을 숙시닐화 및 아세틸화 하면 단백질 효율은 감소되어, 각각 카제인의 55% 및 69%였다.

• 한국식품과학회지
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• 제22권5호
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• pp.590-595
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• 1990

미강으로부터 추출한 단백질과 부분 정제한 단백 분해효소에 미강 지질을 산패시킨 과산화지질 및 이들의 분해산물을 반응시킨 model system에서 아미노산과 효소활성의 변화를 살펴보았다. Protein isolate의 아미노산 조성은 반응 후 현저히 파괴되었으며, 특히 염용성 protein isolate의 경우 90% 이상의 파괴가 관찰되었다. 아미노산 중 aspartic acid, cystine, glutamic acid, histidine, methionine, phynylalanine, 그리고 valine 등은 현저히 감소되었다. Protease 활성의 감소는 formaldehyde와의 반응에서 가장 크게 나타났으며, formic acid, 미강의 과산화지방질, 그리고 미강 산화지질의 hydroperoxide의 순으로 영향을 받았다. 미강 protease 활성 저해에 미치는 영향은 과산화 지방질의 2차 생성물의 영향이 1차 생성물의 영향보다 현저하였다.