• Applied Biological Chemistry
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• v.35 no.3
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• pp.152-156
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• 1992

A study was condoled to investigate the effects of phosphate salts $(Na_2HPO_4\;and\;K_2HPO_4)$ on the emulsion stability of soy protein isolate (SPI) in terms of the salts concentration and addition order. When phosphates were added before emulsification, emulsion stability (ES) of SPI was improved at the concentration of 10 mM, while ES was decreased by addition of phosphates after emulsification. At high phosphate concentrations, ES of SPI was decreased by the addition of phosphates, regardless of the addition order. ES of SPI at the isoelectric point (pH 4.5) or in the presence of $CaCl_2$ was greatly enhanced by the phosphates. In both cases, the overall ES profile was found to be nearly similar to the solubility profile of SPI, indicating the positive relationship between solutibility and emulsion stability of SPI.

• Proceedings of the Korean Society of Food and Cookery Science Conference
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• 2004.10a
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• pp.124-124
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• 2004

• 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.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.5
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• pp.424-432
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• 1985

The effect of additional amounts of subsidiary materials on texture of fish meat paste were examined using Instron Universal Testing Machine to obtain fundamental data for steamed Alaska pollack meat paste showing good qualify. The hardness revealed the good correlation with jelly strength among the six kinds of parameters of Instron texturometer. Products with higher hardness showed a better quality, but those with hardness higher than 16 kg showed decreasing quality with increasing hardness. Predicting the quality of steamed Alaska pollack meat paste with various additional amounts of subsidiary materials as a function of hardness, H, the equation could be deduced as follows: H=11.56+0.54 Xcs, H=12.22-0.23 Xsp and H=11.65-7.13 Xpp. The reasonable equations for predicting the duality of steamed Alaska pollack meat paste with various additional amounts of mixed subsidiary materials could be summarized as follows : H=11.57+0.53Xcs+0.44Xsp, H=11.97-1.83Xpp-0.17Xcs, and H=11.58十0.08Xpp-0.23 Xsp. (Xcs; added amount of corn starch, Xsp: added amount of soy protein isolate, Xpp; added amount of polyphosphate)

• Korean Journal of Food Science and Technology
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• v.22 no.6
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• pp.700-706
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• 1990

The curd yogurt was prepared from milk or milk added with skim milk powder or soy proteins. Acid production by lactic acid bacteria in milk containing additive of 2% was investigated and quality of curd yogurt(sensory property and keeping quality) was examined. Some organic acids in curd yogurt were analyzed by HPLC. The soy proteins, particularly defatted soy flour or soy flour, stimulated acid production by lactic acid bacteria more than skim milk powder. Among the four organisms tested, Leuconostoc mesenteroides and Lactobacillus bulgaricus produced more acid than L. casei and L. delbrueckii. HPLC analysis of organic acids in curd yogurt showed that the amount of lactic acid and acetic acid markedly increased during the fermentation by L. bulgaricus for 24 hours while the amount of citric acid markedly decreased. The major organic acid produced during the fermentation was lactic acid. Addition of soy proteins to milk reduced sensory property of curd yogurt. Among the soy proteins tested, soy protein concentrate or soy protein isolate added sample showed better sensory acceptability than other samples. When curd yogurt was kept at $5^{\circ}C$ for two weeks, titratable acidity, pH and number of viable cells of curd yogurt were not changed.

• Korean Journal of Food Science and Technology
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• v.25 no.4
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• pp.360-365
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• 1993

This study was carried out to examine the effects of phytate addition on the solubility and digestibility of the low-phytate soy protein isolate (LSPI) and high-phytate soy protein isolate (HSPI). In SDS-polyacrylamide gel electrophoresis of soy protein isolate, different patterns of proteins were observed in both HSPI and LSPI at various phytate and pH levels, suggesting that phytate may bind specifically to certain protein fractions at a particular pH. For example, proteins of M.W $1.8{\sim}3.5\;kDa$ resisted phytate binding at acidic pH. LSPI was fractionated into albumin, globulin, gliadin and glutelin, and phytate was shown to bind with difficultly to all three gliadin bands. Effects of phytate on the pepsin digestibility of soy proteins were apparent, especially in the short term digestion.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.3
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• pp.325-330
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• 1995

Seaweed Jellys(Muks) were prepared with sea mustard and sea tangle, Optimum conditions for preparation of seaweed Muks with soy protein were investigated. Gel strength of Muks with sea mustard and soymilk decreased as the quantity of soy milk increased, and increased as the moisture content of soy milk had been decreased. Optimum mixing ratio of seaweed and soy milk was 7 : 1 and optimum temperature of gelation was $65^{\circ}C$. Gel strength of seaweed Muk mixed $5\%$(w/w) of soy protein isolate was higher$(900g/cm^2)$ than those of seaweed Muks with and without soy milk.

• Korean journal of food and cookery science
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• v.10 no.2
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• pp.146-150
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• 1994

The addition of nonfish protein significantly reduced the strength of nonfish protein-incorporated surimi gel in terms of cohesiveness, rigidity and shear force. The sensory textural properties of fiberi-3ed surimi gel product was characterized as the reduction in intensity of undesirable rubberiness, chewiness and firmness, thus increasing the desirability in over all texture. Gel strength of both cohesiveness and rigidity of nonfish protein was inversely correlated with those of nonfish protein-incorporated surimi gel. The variation of texture-modifying properties of nonfish protein in surimi gel was attributed to the differences in thermal hydration and gelation properties of nonfish protein.

• Korean Journal of Food Science and Technology
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• v.27 no.2
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• pp.225-229
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• 1995

Soy oligosaccharide, a low calorie sugar, which is known to improve the intestinal microbial flora, was recovered from the waste of soymilk process by Steffen process. To remove protein contaminants, prior to the Steffen process, pH of the sample was adjusted to $3.5{\sim}4.0$ or calcium chloride was added 8%(w/w) per sugar. Both pretreatment processes were found to remove about $25{\sim}30%$ of the protein initially present in the sample. Using the Steffen process, as much as 85% of soy oligosaccharide could be recovered as a saccharate form. The amounts of calcium chloride and lime used were 20%(w/w) and $100{\sim}120%$(w/w) per total sugar, respectively. After the sugar was desorbed by $CO_{2}$, the final yield of oligosaccharide was 80% while 80% of protein were removed from the original solution. The composition of sugar was similar to that of soybean cooking water.

• Applied Biological Chemistry
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• v.46 no.2
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• pp.113-116
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• 2003

Color value, total color difference $({\triangle}E)$, puncture strength (PS), tensile strength (TS), percent elongation(%E) at break values, and water vapor permeability (WVP) were determined for water-soluble chitosan films added with soy protein isolate (SPI) and $CaCl_2$. Mechanical and water vapor barrier properties of the chitosan films were affected by SPI and $CaCl_2$ concentrations. PS value $(174.5-448.8\;g_f)$ of the chitosan films increased with increasing concentration of $CaCl_2$ TS value of 0.05% $CaCl_2$-added chitosan films significantly increased to 1.58 MPa compared to 0.06 MPa of the control. %E values ranged from 12.25 to 44.80% and increased with increasing concentration of $CaCl_2$. WVP of $CaCl_2$-added films was lower than that of SPI-added films.