• Asian-Australasian Journal of Animal Sciences
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• v.24 no.5
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• pp.670-677
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• 2011

The growth rate of the young pig is generally much less than it's potential and may be constrained by endocrine status as well as nutrient intake. Growth factors are present in relatively high quantities in colostrum and play an important part in gut development. It is possible that supplementation of colostrum protein isolate may stimulate gut and whole body growth in the pig. Eight male and 8 female (Large Whitex${\times}$Landrace) piglets were weaned at 1 d of age after each pig had obtained colostrum from their dam, and were trained to consume one of two liquid diets. The two diets were based on either a colostrum protein isolate (n = 4 males and 4 females) or whey protein concentrate (n = 4 males and 4 females) and were formulated to contain equal levels of crude protein and amino acids. Pigs were fed their diets ad libitum for 28 days after which time 12 pigs were euthanised and various tissues and organs weighed. Pigs were bled for IGF-I analyses at 21 and 28 days of age. Daily gain was higher in pigs consuming the colostrum isolate (171 vs. 216 g/d, p = 0.010), particularly between 2 and 4 weeks of age (212 vs. 298 g/d, p = 0.010). Pigs tended to consume more of the liquid feed containing colostrum isolate (25.5 vs. 29.1 kg, p = 0.074) and gained more live weight per unit of liquid feed (0.203 vs. 0.223 g/g, p = 0.056). There were no effects of sex on growth performance. Pigs consuming the diet supplemented with colostrum isolate had higher (p<0.05) full gut weight (445 vs. 554 g, p = 0.026), empty gut weight (356 vs. 463 g, p = 0.008), stomach weight (42.2 vs. 54.4 g, p = 0.001), small intestine weight (222 vs. 275 g, p = 0.025) and large intestine weight (63.7 vs. 98.0 g, p = 0.005). Plasma IGF-I (99 vs. 150 ng/ml, p<0.001) and IGF-II (265 vs. 406 ng/ml, p<0.001) were higher in pigs fed colostrum isolate. Pigs consuming colostrum protein isolate ate more, grew faster and had higher plasma IGF-I concentrations than pigs consuming a diet with similar macronutrient content but devoid of growth factors.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.2
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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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• v.15 no.4
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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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.1
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• pp.8-13
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• 2010

The angiotensin converting enzyme (ACE) inhibition effect of soybean protein isolate hydrolysate was studied using protease. Soybean protein isolate was hydrolysed by seven enzymes (Alcalase 2.4 L, Flavourzyme 500 MG, GC 106, Multifect Neutral, Neutrase 0.8 L, Papain 30,000 and Protamex), enzyme concentrations (0, 0.5, 1.0 and 1.5%), at various hydrolysis times (0, 1, 2, 3, 4, 5 and 6 hr) and suspension concentrations (1, 5, 7, 10 and 15%). Absorbance at 280 nm, brix and ACE inhibitory activity of soybean protein isolate hydrolysates were investigated. Absorbance at 280 nm and brix of Alcalase 2.4 L treatment were higher than other enzyme treatments. The optimum condition of hydrolysis was Alcalase 2.4 L, 1% enzyme concentration, 5% suspension concentration for 4 hr. $IC_{50}$ value of ACE inhibitory activity of soybean protein isolate hydrolysate was $79.94 {\mu}g/mL$. These results suggest that soybean isolate protein hydrolysate from Alcalase 2.4 L may be of benefit for developing antihypertensive therapeutics.

• Journal of Nutrition and Health
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• v.36 no.6
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• pp.549-558
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• 2003

The purpose of this study was to determine which differences in the source of protein (soy vs casein) and isoflavones in soy protein are responsible for the differential effects of bone marks and hormones in growing female rats. Forty-two 21-day-old Sprague-Dawley female rats were randomly assigned to one of three groups, consuming casein (control group), soy protein isolate (57 mg isoflavones/100 g diet), or soy protein concentrate (about 1.2 mg isoflavones/100 g diet). All rats were fed on experimental diet and deionized water ad libitum for 9 weeks. Bone formation was measured by serum osteocalcin and alkaline phosphatase (ALP) concentrations. And bone resorption rate was measured by deoxypyridinoline (DPD) crosslinks immunoassay and corrected for creatinine. Serum osteocalcin, growth hormone, estrogen and calcitonin were analyzed using radioimmunoassay kits. Diet did not affect weight gain and mean food intake. Food efficiency ratio was lower in the soy protein groups. The soy isolate group had a higher ALP and osteocalcin concentration and lower crosslinks value than the casein group. Therefore, the soy isolate groups had a higher bone formation/resorption ratio than the casein group. And, the soy group had significantly higher growth hormone than the casein group. The findings of this study suggest that soy protein and isoflavones are beneficial for bone formation in growing female rats. Therefore, exposure to these soy protein and isoflavones early in life may have benefits for osteoporosis prevention.

• Applied Biological Chemistry
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• v.35 no.6
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• pp.457-461
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• 1992

The emulsion stabilizing properties of soy protein isolate (SPI) were investigated in terms of the protein and oil concentration. Particularly, the dependence of emulsion stability on the oil particle size and viscosity of emulsion was studied in conjunction with the adsorption pattern of protein onto the water/oil interface during emulsification. The data showed that increasing protein concentration decreased the oil particle size and increased the emulsion viscosity, resulting in the enhanced emulsion stability. In contrast, increasing oil concentration increased both the oil praticle size and the emulsion viscosity, and thus emulsion stability varied depending on which factor predominated the overall emulsion system.

• Korean Journal of Food Science and Technology
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• v.23 no.6
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• pp.656-660
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• 1991

Heats of moisture adsorption of the sunflower nutmeat products (ground nutmeat, meal, protein concentrate and protein isolate) were determined from their isosteres at temperatures 10, 20 and $30^{\circ}C$. The changes in the heat of adsorption with moisture level were analyzed by Hunter equation. The Hunter equation was valid for representing the relationship between the heat of adsorption and the moisture content for the sunflower nutmeat products, and the accuracy-of-fit increased as protein content of the materials increased. The heat of adsorption decreased as moisture content increased, but increased as protein content increased. The heats of adsorption were 11.8-10.6 kcal/mole for the ground nutmeat at 4-12% moisture (d.b.) and 12.4-11.0 kcal/mole for the protein isolate at 6-20% moisture (d.b.).

• Korean journal of food and cookery science
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• v.24 no.3
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• pp.304-311
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• 2008

This study examined Jeung-pyun(JP) Retrogradation in samples containing 3% whole protein, 7S protein, or 11S protein(w/w) that were stored at $4^{\circ}C$ for 6, 12, 24 and 72 hr. Rheometery and differential scanning calorimetry(DSC) were used in the analysis. The pH of the dough decreased during the fermentation process, but it increased after steaming. The JP prepared with soybean protein isolate(SPI) had higher pH than the control group. During storage the textural characteristics of the JP showed effects according to the additions of SPI. After 6 hr of storage, the JP samples containing soybean flour, whole protein, 7S protein, and 11S protein had lower hardness valuse. From 4 hr to 12 hr, higher springiness values were found in the samples containing whole protein, 7S protein and 11S protein. At 0 hr, the control group had the highest cohesiveness value, but after 24 hr it presented the lowest value. For gumminess, after 6 hr of storage, the control group offered the lowest value. Whereas after 12 hr of storage the whole protein group showed the highest value, and at 24 hr, the whole protein, 7S protein, and 11S protein groups had higher values. According to the DSC results, the 11S protein group had lower enthalpy values(${\bigtriangleup}H$) suggesting that adding 11S protein to JP might improve starch retrogradation. After 72 hr of storage, the control group had the highest onset temperature($T_{o}$) and peak temperature($T_{p}$) whereas the 7S and 11S protein JP samples had higher conclusion temperatures($T_{c}$). Therefore, based on the different analysis result between the control and treatment groups, the addition of SPI to Jp had effects on retrogradation.

• Composites Research
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• v.27 no.5
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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.

• Korean Journal of Food Science and Technology
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• v.22 no.3
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• pp.350-356
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• 1990

Functional properties such as nitrogen solubility, emulsifying property, foaming property, and water and oil absorption of sesame and perilla protein isolates were determined at pH range of 2-10 and ionic strength of 0-0.5M NaCl. Nitrogen solubility of protein isolates in distilled water showed minimum value at pH6.0 in sesame and at pH 4.0 in perilla and soybean protein isolates, and significantly increased above pH 8.0 in all samples. Addition of 0.1M NaCl solution increased nitrogen solubility, however, decreased in 0.5M NaCl solution. Emulsion activities of all the protein isolates showed minimum value at pH 4.0 and increased in 0.1M NaCl solutions while it was reduced in 0.5M NaCl solutions. The perilla protein isolate showed higher emulsion activity than that of soybean and sesame protein isolates at above pH 6.0. Foaming capacities of sesame and perilla protein isolates were lower than soybean protein isolate and generally all of the samples showed higher profiles in NaCl solutions. The foaming stability of soybean isolate decreased abruptly in 10min, while it was slowly decreased for sesame and perilla isolates during initial 30 min. Oil absorption capacity of perilla protein isolate was higher than that of sesame and soybean protein isolates. Water absorption capacity was similar among the three samples studied.