• Proceedings of the KSAR Conference
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• 2004.06a
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• pp.212-212
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• 2004

Collagen has been widely studied for medical applications. Previous studies have shown that the bovine β-casein promoter were able to drive cell-specific and hormone-dependent expression to a mouse mammary cell line but failed to induce accurate expression to the mammary gland. of transgenic mice. (omitted)

• Korean Journal of Food Science and Technology
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• v.22 no.7
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• pp.774-779
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• 1990

$[^{14}C]$-radiolabelled ${\beta}-lactoglobulin$ was used for the studies on the effect of thermalization and ultrafiltration for the increase of cheese yield. 4.33% of ${\beta}-lactoglobulin$ was incorporated through thermalization. $3.20{\sim}3.65%$ of ${\beta}-lactoglobulin$ was more incorporated with cheese curd in the thermalization and ultrafiltration than without ultrafiltration process. Comparing with protein increase, other whey proteins might be incorporated with casein micelles. Loss of $[^{14}]C-{\beta}-lactoglobulin$ through processing and adsorption to membrane during ultrafiltration was only 1.03%.

• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.2
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• pp.122-136
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• 1983

The effect of dietary casein, calcium, magnesium and some vegetable oils such as seasme, perilla and soybean oil on the serum cholesterol level in the rabbit were studied for a period of 5 weeks using isocalories and isonitrogenous as basal diets. The experimental rabbits fed the following basal diets containing crude protein 68.47%, carbohydrates 13.35%. fats 16.18% and vegetable oil 10%. casein 10%, calcium and magnesium according to experimental plan making. In order to calculate the feeding efficiency, protein efficiency and calorie efficiency during period, the body weight gains were measured at the same time using same balance, respectively. The results are summarized as follows. Body weight gains per week of the group fed perilla oil, calcium and basal diet were the higher than any other groups. And body weights gains per week of the group fed basal diet, vegetable oil were the lower than any other groups. In the case of efficiency of reed, protein and calorie, the efficiency ratios of the group fed perilla oil were the higher than any other groups. Especially, perilla oil and calcium diet effect on body weight gain in rabbit. In the case of serum protein, the total proteins in serum were almost same value for all the groups. Serum albumin of group fed basal diet. vegetable oil and casein were the higher than any other groups. The ${\alpha}$-globulin of the groups, fed basal diet and calcium was the lower than any other grosps. The ${\beta}$-globulins of the groups fed basad diet, perilla oil and casein were the highest value. In serum lipoprotein, lipalbumin was almost same value for the groups fed vegetable oil, but fed vegetable oil and calcium diet was the lowest value. The ${\beta}$-lipoprotein in high cholesterol level group was increased some degree, the group fed perilla oil added was lower. The ratio of ${\beta}$-lipoprotein per lipalbumin was from 0.11 to 0.26. The ratio of lipalbumin per total lipoprotein was high in calcium and soybean oil added diet. In serum triglyceride, the level of triglyceride of groups fed seasme oil or perilla oil was the higher than any othe groups, but in the group fed casein and calcium or magnesium, the level of triglyceride level was decreased. Calcium and magnesium effect on triglyceridge level lowering action. In serum total cholesterol, the group does fed vegetable oil with basal diet and casein added more, total cholesterol level increased as much as triglyceride level increased. But the group does fed perilla oil and magnesium shows total cholesterol level decreased remarkably. In the group fed basal diet with calium, the amount of serum calcium was increased, but of serum magnesium was decreased. In the case of blood glucose, the group fed basal diet and vegetable oil was decreased. According to the regression and correlation coefficient in blood components in rabbit, there are positive correlation $${\gamma}{\sim_=}1$$ between serum cholesterol and triglyceride, ${\beta}$-lipoprotein, ${\alpha}$-globulin, calcium and magnesium according to diet composition. From the above results, the serum cholesterol level lowering factors in rabbit, was the amount of triglyceride and ${\beta}$-lipoprotein which was decreased in perilla oil fed. It assumes that serum cholesterol and triglyceride level lowering factors are not only unsaturation degree of fatty acid but the amount of calcium and magnesium and the ratio calcium per magnesium 2:1 in the diet.

• Food Science of Animal Resources
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• v.20 no.1
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• pp.8-14
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• 2000

In order to examine physicochemical gelation behavior of ultra high temperature(UHT) pasteurized milk during storage at 4$^{\circ}C$ and 25$^{\circ}C$, pH, electrophoresis, alcohol test, sialic acid contents and free amino groups contents were biweekly determined. The pH of UHT pasteurized milk decreased with increasing storage time. Gelation of the UHT milk occured faster at 25$^{\circ}C$ than at 4$^{\circ}C$ with larger decreasing rate of pH. The alcohol test showed positive results at lower pH than 6.5, which could indicate the casein instability and beginning of gelation. The electrophoretic patterns showed a decrease in the concentrations of all caseins. Degradation of k-casein was faster in all cases, while $\alpha$-casein and $\beta$-casein were also extensively degraded later. The sialic acid contents of the samples increased gradually during storage, and the increasing rate was higher before gel formation. The free amino groups of the samples increased gradually during storage. The increasing rate of free amino groups was faster at 25$^{\circ}C$ than at 4$^{\circ}C$. The samples stored at 25$^{\circ}C$ gelled earlier than those stored at 25$^{\circ}C$, with corresponding increase of free amino groups. The residual proteolytic enzymes, which survived during the UHT heat treatments and were reactivated during storage, could be responsible for UHT pasteurized milk gelation during storage. It is assumed that proteolytic degradation of caseins followed by aggregation would be attributable to complicated reaction mechanism.

• Preventive Nutrition and Food Science
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• v.5 no.4
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• pp.200-204
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• 2000

Protein conjugation of curdlan belonging to $\beta$-1, 3-glucan was carried out to improve it surface functionalities. The glucan was mixed with phosvitin, {TEX}$$\alpha$_{s}${/TEX}-casein, lysozyme or ovalbumin, respectively. The mixture was freeze-dried, and he resulting powder was incubated at 6$0^{\circ}C$ and 79% relative humidity for 12 days in order to generate a controlled Maillard reaction between curdlan and proteins. conjugation with unfolding proteins, i.e., phosvitin and {TEX}$$\alpha$_{s}${/TEX}-casein, drastically increased the solubility of the glucan, whereas lysozyme and ovalbmin did not. The solubility in water of curdlan was 3.44% for the phosvitin conjugate and 1.09% for the {TEX}$$\alpha$_{s}${/TEX}-casein conjugate. SDS-slab polyacrylamide gel electrophoresis showed that curdlan was solubilized due to covalent binding with phosvitin. Emulsifying properties of curdlan were substantially improved by the conjugation with phosvitin and {TEX}$$\alpha$_{s}${/TEX}-casein. Emulsion stability of the curdlan-phosvitin conjugate was about 2.9 times greater than that of the curdlan-phosvitin mixture.

• Korean Journal of Food Science and Technology
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• v.34 no.2
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• pp.249-254
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• 2002

To determine the abilities as both lactic starter and probiotics for fermented foods, we investigated the potency of acid production, proteolytic activity and lactose metabolism of Lactobacillus amylovorus IMC-1. And the strain was cultured with lactococci in 10% skim milk medium. It was also examined the bactericidal action of antibacterial substance, produced by the strain IMC-1, against pathogenic bacteria. L. amylovorus IMC-1 showed excellent production of acid in 10% skim milk supplemented with yeast extract, and produced 0.8 and 2.7% of acid at 12 and 72 h incubation, respectively. It was found that the activity of ${\beta}-galactosidase$, about $39\;{\mu}M/minute/dry$ cell weight (mg), was stronger than that of $phospho-{\beta}-galactosidase$ in the strain IMC-1. The strain showed weak proteolytic activity in 10% skim milk, thus it produced 6 and $69\;{\mu}g/mL$ of free tyrosine at 12 and 72 h cultivation, respectively. It was known that the strain utilized mainly ${\alpha}-casein$ than ${\beta}-casein$ from patterns of SDS-PAGE. Mixed culture produced more acid than single cultures of L. amylovorus IMC-1 and Streptococcus thermophilus NIAI 510. Single culture of Str. thermophilus and mixed culture showed increasing cheese flavor with incubation times. Optimal fermentation time of mixed culture for the acid production and flora of lactic starter was 16 and 12 h by adding 0.1 and 0.5% of yeast extract to 10% skim milk, respectively. Antibacterial substance produced by the strain IMC-1 reduced about 2 log of the viable cell counts of both Escherichia coli O157 and Shigella flexneri after 24 and 4 h incubation, and they were not detected after 48 and 6 h incubation, respectively.

• Korean Journal of Food Science and Technology
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• v.17 no.5
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• pp.389-398
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• 1985

To shorten the processing of cheese slurry, four different slurries, ie, Control, Cheddar 1 and 2, and Italian-type that were made of Na-caseinates, cream, trace elements, lactic culture, and enzymes were fermented at $30^{\circ}C$ for 7days with daily stirring. PH, titratable acidity, soluble nitrogen, viable cell count, active SH groups, total volatile fatty acid, free fatty acid, electrophoretic patterns of degraded caseins, and viscosity were analyzed to investigate physicochemical properties of fermented slurries. Acid production was accelerated in the cheese slurries with protease than that without the enzyme and PH of the former was decreased after three days of fermentation to 4.90. The Change of titratable acidity agreed to PH patterns. Soluble nitrogen of the Control slurry was increased slowly for four days and then rapidly to 40% of total nitrogen while those containing protease to 70%. The protease of lactic cultures used (Streptococcus lactis and Streptococcus cremoris) broke down as-casein more rapidly than $\beta$-casein and most proteins were degraded to peptides and amino acids after three days of fermentation. Total volatile fatty acids were increased by added lipase and free fatty acids composition analyzed by GLC in cheddar slurry with 0.00001% lipase was similar to that of commercial cheddar cheese, while that in Italian-type slurry was a half of that in commercial Italian cheese. Active SH groups were increased in the cheese slurries with glutathione from fourth day of fermentation. The viscosity of slurries decreased very rapidly by addition of protease.

• Clinical and Experimental Pediatrics
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• v.49 no.10
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• pp.1061-1066
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• 2006

Purpose : The purpose of this study was to research whether measurement of cow's milk specific IgE on the newborn would be helpful in the diagnosis of cow's milk allergy. We tried to find out the relation between cow's milk specific IgE and other allergy diseases by following up cases. Methods : We reviewed clinical features of 87 episodes in infants less than 4 weeks old who were positive in cow's milk specific IgE test. For the study group, history taking, physical examinations, elimination and cow's milk specific IgE tests were carried out. We investigated the connection among cow' milk specific IgE, allergic disease and family history in 40 of 87 patients we could follow up on. Results : The mean age of the study group was $17.2{\pm}5.4days$. The subjects were classified in four groups according into allergens : 87 milk allergy positive patients, 24 casein positive, 38 ${\alpha}$-lactoalbumin positive, and 75 ${\beta}$-lactoglobulin positive. The number of patients who had follow-ups for more than 6 months to was 40(45.9 percent). The patients whose parents had allergic disease numberred 10(25 percent). Fiften patients had allergic diseases, 4 had asthma and 11 atopic dermatitis. According to the follow-up study, there is a significant relation between casein positive patients and allergic disease. But there is no statistical and significant relation between cow's milk specific IgE and a family history of allergic disease. Conclusion : For the newborn babies, elimination tests and cow's milk specific IgE tests can be useful in the diagnosis of IgE-mediated or mixed milk allergies.

• Animal Bioscience
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• v.35 no.1
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• pp.13-21
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• 2022

Objective: The aim of the study was to evaluate the influence of gene polymorphisms and nongenetic factors on the somatic cell score (SCS) in the milk of Holstein (n = 148) and Simmental (n = 73) cows and their crosses (n = 6). Methods: The SCS was calculated by the formula SCS = log₂(SCC/100,000)+3, where SCC is the somatic cell count. Polymorphisms in the casein alpha S1 (CSN1S1), beta-casein (CSN2), kappa-casein (CSN3), beta-lactoglobulin (LGB), acyl-CoA diacylglycerol transferase 1 (DGAT1), leptin (LEP), fatty acid synthase (FASN), stearoyl CoA desaturase 1 (SCD1), and 1-acylglycerol-3-phosphate O-acyltransferase 6 (AGPAT6) genes were genotyped, and association analysis to the SCS in the cow's milk was performed. Further, the impact of breed, farm, year, month of the year, lactation stage and parity on the SCS were analysed. Phenotype correlations among SCS and milk constituents were computed by Pearson correlation coefficients. Results: Only CSN2 genotypes A¹/A² were found to have significant association with the SCS (p<0.05), and alleles of CSN1S1 and DGAT1 genes (p<0.05). Other polymorphisms were not found to be significant. SCS had significant association with the combined effect of farm and year, lactation stage and month of the year. Lactation parity and breed had not significant association with SCS. The phenotypic correlation of SCS to lactose content was negative and significant, while the correlation to protein content was positive and significant. The correlations of SCS to fat, casein, nonfat solids, urea, citric acid, acetone and ketones contents were very low and not significant. Conclusion: Only CSN2 genotypes, CSN1S1 and DGAT1 alleles did show an obvious association to the SCS. The results confirmed the importance of general quality management of farms on the microbial milk quality, and effects of lactation stage and month of the year. The lactose content in milk reflects the health status of the udder.

• Korean Journal of Microbiology
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• v.45 no.4
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• pp.291-299
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• 2009

To elucidate HtrA3's functional roles in the HtrA3 mediated cellular processes, it is necessary to investigate its biochemical characteristics. In the present study, we constructed the plasmids encoding putative mature HtrA3 proteins (M1-HtrA3 and M2-HtrA3) based on the putative maturation sites of highly homologous HtrA1 and mouse HtrA3. We used the pGEX bacterial expression system to develop a simple and rapid purification for the recombinant HtrA3 protein. Although yields of the mature HtrA3 proteins were slightly low as 10~50 ${\mu}g$/L, the amounts and purity of M1- and M2-HtrA3 were enough to investigate their proteolytic activities. The putative mature HtrA3 proteins have proteolytic activity which could cleave $\beta$-casein as an exogenous substrate. We compared the proteolytic activity between the HtrA family, HtrA1, HtrA2, and HtrA3. The cleavage activity of HtrA3 and HtrA2 were 2 folds higher than that of HtrA1, respectively. Our study provides a method for generating useful reagents to identify natural substrates of HtrA3 in the further studies.