• Journal of Nutrition and Health
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• v.17 no.1
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• pp.68-77
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• 1984

The present study was designed to observe the effects of soyprotein and casein with or without cholesterol on serum and liver lipids in male rats. The 6 experimental groups were as fellows ; SF ; soyprotein, cholesterol-free diet. SC ; soyprotein, 0.5% cholesterol added diet. CF ; casein, cholesterol-free diet CC ; casein,0.5% cholesterol added diet. SCF ; protein mixture of soyprotein and casein(1 : 1), cholesterol-free diet SCC ; mixed protein, 0.5% cholesterol added diet. The hypocholesterolemic and hypotriglyceridemic effects of soyprotein were observed at 3 weeks, but these effects disappeared at 6 weeks. The hypocholesterolemic effect of soyprotein was more obvious when the 0.5% cholesterol was supplemented in the diets. The serum free cholesterol level was not affected by the dietary protein source or the dietary cholesterol, therefore, the difference in serum total cholesterol among groups seems due to the difference in cholesterol esters. There was a tendency of a higher percentage of HDL in soyprotein groups compared to casein groups at 1 week, however, this tendency disappeared with time. The liver cholesterol and triglyceride contents were not differ among cholesterol-free diet groups, however, with addition of cholesterol, those of soyprotein groups were significantly lower than casein groups. The higher serum arginine/lysine ratio of soyprotein groups may offer the part of explanation of its hypocholesterolemic effect.

• Journal of the East Asian Society of Dietary Life
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• v.11 no.5
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• pp.368-378
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• 2001

This study was performed to investigate the effects of isolated soyprotein and salt (NaCl) restriction on the serum lipid and the kidney functions of streptozotocin-induced diabetic rats. Sprague-Dawley males of normal and streptozotocin-induced diabetic rats were raised for 6 weeds divided into 4 groups each according to protein sources and salt levels. The sources of protein were isolated soyprotein and casein. Salt levels tested were 0.1% (normal) and 0.01% (low). The results are summarized as fellows: kidney weight, blood glucose, hemoglobinAlc, GFR and urinary protein of diabetic groups were higher than those of normal groups. Isolated soyprotein lowered total lipids, triglycerides, and total cholesterol in serum and plasma angiotensin II concentration as well as alleviated kidney enlargement and GFR in diabetic rats. Salt restriction didn\\`t affect serum lipid level but decreased GFR and increased angiotensin If concentration. In conclusion, isolated soyprotein decreased serum lipids, plasma angiotensin II concentration, sidney enlargement and GFR, while salt restriction increased plasma angiotensin II concentration. The results suggest that isolated soyprotein and salt restriction seem to cause different effects on plasma angiotensin II concentration and that isolated soyprotein might be of value in the prevention of diabetic artherosclerosis and diabetic hypertension.

• Korean Journal of Food Science and Technology
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• v.10 no.2
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• pp.143-150
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• 1978

In our previous report (Korean J. Food Sci. Technol., 9, 123. (1977), functional properties of soyprotein isolates prepared from defatted soybean meal were studied. Using those properties soyprotein fibers, which may be acceptable as meat analogs, were prepared with protein spinning apparatus. Soyprotein can be converted into the suitable form for the spinning by denaturation with alkali (0.6%) and continuous fibers were spun by extruding spinning solution into an 20% NaCl-1 N acetic acid coagulating bath. The process for producing soyprotein fibers on a bench scale was described and break strength, break elongation and textural parameters of the fibers formed were evaluated. The possible scheme of formation of soyprotein fibers was discussed.

• Applied Biological Chemistry
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• v.34 no.4
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• pp.353-359
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• 1991

As a tool for the texture analyses of the soyprotein fibers, the scanning electron microscopical microstructure were studied. With the results of TPA(Texture Profile Analysis), microstructural analyses of the soyprotein fibers showed that the disulfide and hydrogen bonds are one of the most important factors determining the shape and maintenance of fiber struture. The microstructures of the hydrated soyprotein dispersion and dope, as starting materials of the soyprotein fiber were presented.

• Korean Journal of Food Science and Technology
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• v.23 no.6
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• pp.759-763
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• 1991

The dynamic rheological properties of the dope and the hydrated disperson of the soyprotein, as a starting material of soyprotein fiber, were studied to investigate their viscoelastic properties. The increase of protein concentration in the both cases of the dope and the dispersion resulted in the establishment of intermolecular reaction of the protein. With the addition of alkali solution to the dispersion, the dope shows the characteristics of very lightly cross-linked high molecular weight polymer. In constrast, the dispersion shows the properties of an amorphorous polymer. The effects of chemical modification of the dispersion on the dynamic properties were also investigated.

• Journal of Nutrition and Health
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• v.17 no.1
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• pp.20-30
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• 1984

This experiment was designed to investigate the effects of the mixing ratio of soyprotein and casein, and the level of pectin combined with the mixture on lipid metabolism in rats. Forty-eight male weanling rats of Wistar strain weighing 58.8\;{\pm}\;1.9g$ were divided into six groups by completely randomized block design and fed 10% protein diet for four weeks. Two types of protein mixtures (casein to soyprotein mixing ratio of 1 : 3 and 2: 1)combined with 0.5% , 3%, and 5% of pectin were employed for experimental diets. The results obtained in the study are summarized as follows ; 1) Feed efficiency ratio and protein efficiency ratio were not significantly different among six groups for the whole experimental period, but those for high casein-low pectin group were significantly higher than the ones for high soy-high pectin group at 4th week of the experimental period. 2) Gross fecal dried weight and fecal lipid excretion were higher in high pectin groups of both protein combinations. Therefore, the apparent fat digestibility and absorption appeared to be significantly low in high pectin groups. 3) Pectin was effective in lowering serum lipid and cholesterol levels in high casein groups, but no effect of pectin was noted in high soyprotein groups. 4) Lipid and cholesterol contents of the liver were higher in high soy-low pectin group than the others. And no marked differences in lipid and cholesterol contents in the kidney and carcass were observed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.1
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• pp.90-97
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• 1994

Effect of addition of oil , sucrose, dextrin and oil-sucrose (1 : 1 w/w) mixture on SPI tofu was investigated. The characteristics measured were yield , water holding capacity , textural and organoleptic properties. THe SPI tofufwas prepared by coagulation of soyprotein isolate (SP) suspensino by CaCl$_2$ , CaSo$_4$ an dGDL , followed by compression . Addition of oil to SPI increased the tofu yield and water holding capacity, particulary for those tofu coagulated by CaCl$_2$. Eventhough dextrin addition decreased the yield, it showed the most improving effect on water holding capacity. The tofu prepared by CaSO$_4$coagulant resulted highest in yield and water holding capacity. Hardness was found to be decreased as the oil, sucrose and dextrin added more and adhesiveness, cohesiveness and guminess were also affected. The sensory evaluation showed the SPI tofu prepared by CaSO$_4$ and 10% addition of oil and sucrose mixture to be realtively high in hardness , elasticity and uniformity of the texture.

• The Korean Journal of Food And Nutrition
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• v.24 no.4
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• pp.740-745
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• 2011

Ohmic heating uses electric resistance heat which occurs equally and rapidly inside food when an electrical current is passed throught. In this study, we observed the physical & chemical characteristics changes which occurs in soybean protein during heating denaturation by using ohmic and conventional heating. After the ohmic heating process, we could not find any change of the primary protein structure in the denaturated soy protein samples. However, the rate of imbibed water(RIW) of the ohmic samples was 2 times faster than that of the conventional samples. Also the ANS-surface hydrophobicity was decreased, which is very closely related to RIW. In the differential scanning calorimeter(DSC) analysis result, all 7S soyprotein fraction samples were completely denaturated by ohmic and conventional heating. However, the 11S samples were completely denatured only by ohmic heating. According to the DSC result, we decided that soyprotein was damaged by temperature and electrical current during ohmic heating. The damage of electrical current was a cause of the characteristic changes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.1
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• pp.98-103
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• 1994

Some quality characteristics of tofu prepared with soyprotein isolate (SPI) were investigated to study the effects of various ratio of coagulants mixture and addition of oil, sucrose and dextrin. The tofu was prepared by addition of coagulants into the boiled SPI suspension and compression. The results showed that the mixed coagulants of CaCl $_2$-GDL(50 :50) and CaSO$_4$-GDL(25 :75) resulted the highest volume yield of 4.23g/g SPI among the various ratios of CaCl$_2$-CaSO$_4$, CaCl$_2$-GDL and CaSO$_4$-GDL. The water holding capacity(WHC) expressed as the area of water absorbed on filter paper was relatively high for those tofu coagulation with CaCl$_2$-GDL(75 : 25) and CaSO$_4$ -GDL(75 : 25). Addition of sucrose or oil-sucrose (1 : 1) decreased the yield wihle WHC was improved. Their addition also caused less hard and cohesive tofu which was coagulated by CaCl$_2$-GDL(75 : 25) and CaSO$_4$-GDL(75 : 25).

• Journal of Nutrition and Health
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• v.17 no.2
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• pp.94-100
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• 1984

The effect of methionine supplementation to the isolated soyprotein(ISP) diet on the growth, body metabolism and composition of the Albino male rats was studied. Three levels(0.3,0.6 and 0.9%) of methionine were supplemented to the ISP diet with the constant levels of energy and protein of 3,600 kcal/kg and 20%, respectively. The body weight and weight gain of the growing rats were significantly increased by 0.3% methionine supplementation to the ISP diet compared to the ISP diet(P< 0.05).The effects of methionine supplementation to the ISP diet tended to be larger with increasing of the level of methionine supplementation, 0.6 and 0.9%, were statistically insignificant. Food and gross energy intake of growing rats fed the ISP diet or the ISP supplemented with methionine diet were lower than those fed the casein diet(P< 0.05). FER and PER of all the methionine supplemented diets were higher than those of the ISP or casein diet (P< 0.05) without significant differences among the supplementation levels of methionine to the diets. The weight gain of adult rats fed 0.9% methionine supplemented ISP diet were higher than those of the other treatments with significant difference. The effects of methionine supplementation to the ISP diet on the protein digestibility, BV, NPU, N-balance, N-retention, and body and liver compositions were not significant.