• Korean Journal of Animal Reproduction
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• v.21 no.1
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• pp.1-7
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• 1997

Recently the production of transgenic animals to express foreign proteins in mammary glands has been a routine procedure. However, it still takes a considerable time and effort, and is faced with various technical challenges until the protein of interest is successfully made. Thus, a development of an a vitro model for mamm a ary-specific gene expression for recombinant genes was carried out in this study. To this end, bovine $\alpha$$_S1$ casein cDNA was inserted at the multiple cloning site of pMSG vector under the control of MMTV promoter. MCF$_7$ cells were tran sfected with pMSG $\alpha$$_S1$ CN by CaP0$_4$ precipitation. Transfectants were selected in HAT medium and induced with dexamethasone. The cells were analyzed with chicken anti-casein and FITC-labeled rabbit anti-chicken antibodies. The results showed that dexamethasone induced 30-40 fold increase in the MMTV- $\alpha$$_S1$ casein e expression. Therefore MCF$_7$ cells, which have multiple steroid receptors, along with pMSG vector can be used as an in vitro model for the study of mammary-specific gene expression.

• Korean Journal of Food Science and Technology
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• v.32 no.3
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• pp.564-569
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• 2000

An enzyme-linked immunosorbent assay(ELISA) was developed for the detection of milk proteins in processed foods. The ${\alpha}_{s1}-casein({\alpha}_{s1}-CN)$, a heat stable major milk protein, was immunized into rabbits to produce specific antibodies. When competitive indirect ELISA(ciELISA) using $anti-{\alpha}_{s1}-CN$ antibodies was established, its detection limit was $0.1\;{\mu}g/mL$. The reactivities of the specific antibodies toward ${\alpha}_{s1}-CN$, skim milk, ${\beta}-CN$ and whey protein isolate(WPI) were 100, 37, 0.14 and 0.04%, respectively, as determined by ciELISA. However $anti-{\alpha}_{s1}-CN$ antibodies did not have any reactivity to other milk proteins such as ${\beta}-lactoglobulin,\;{\alpha}-lactalbumin$, bovine serum albumin, and isolated soy protein. When sandwich ELISA was established, its detection limit was $0.01\;{\mu}g/mL$ which was 10 times more sensitive than that of ciELISA. In the spike test which was performed by adding 1-10% of whole CN to market milk, mean assay recovery as determined by sandwich ELISA was 94.8%(CV, 8.2%). Food stuffs and dairy products were assayed by sandwich ELISA to show 29, 0.13, 0.25, and 6.9% of whole CN in skim milk powder, WPI, semi-solid yoghurt, and processed cheese, respectively.

• Journal of Dairy Science and Biotechnology
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• v.34 no.3
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• pp.173-180
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• 2016

In many countries, goat milk is an excellent nutrient source and is less allergenic for children and the elderly. The casein composition of goat milk consists largely of ${\beta}$-casein and lower amounts of ${\alpha}_{s1}$-casein, which may interfere with digestion by forming solid curds in the human stomach. Goat milk contains small fat globules and large amounts of medium chain fatty acids for, better digestibility, as well as abundant minerals and vitamins with high absorption rates. Recently, the medical benefits of goat milk in different human disorders have been recognized, leading to an increased interest in developing functional foods with goat milk, particularly for individuals with malabsorption syndrome. However, the physiological and biochemical properties of goat milk are largely unknown. We review the importance of goat milk as a potential functional food by providing scientific evidence confirming its health benefits.

• Journal of Aquaculture
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• v.18 no.4
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• pp.245-251
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• 2005

This study was investigated the condition of their maximum activity to assay the enzymes of rotifer, Brachionus rotundiformis의 $\alpha$-amylase, total alkaline Protease, trypsin and TG-lipase activities of rotifer were higher and more sensitive in phosphate-NaOH buffer than Tris-HCl buffer. $\alpha$-amylase, trypsin and TG-lipase activities were appeared the maximum at pH 8.0, and total alkaline protease activity showed the maximum activity at pH 7.0. $\alpha$-amylase activity showed the highest activity at $40^{\circ}C$, and total alkaline protease and trypsin activities were assayed the highest at $55{\~}60^{\circ}C$. However, TG-lipase activity was appeared the highest at $25{\~}30^{\circ}C$. The optimum substrate concentration of enzyme activity of a-amylase, total alkaline protease, rypsin and TG-lipase were $3.5\%$ starch, $\0.6%$ azo-casein, $87.5{\mu}M$ BApNA and 81.2 mM olive oil, respectively. The optimum reaction time of enzyme activity of $\alpha$-amylase, total alkaline protease, trypsin and TG-lipase were increased up to 40, 60, 30 and 25 min., respectively. The data obtained in this study could be used for the digestive enzyme research of rotifer, B. rotundiformis.

• 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.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.5
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• pp.654-660
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• 2013

Three Korean native steers ($779{\pm}24$ kg) fitted with duodenal cannulas were used in a $3{\times}3$ Latin square design to investigate the influence of oral administration of soluble proteins, intact casein (IC) and acid hydrolyzed casein (AHC), on gastro-intestinal hormone (GIH) secretion in the blood and pancreatic ${\alpha}$-amylase activity in the duodenum. Oral treatment consisted of a basic diet (control), IC (C+100% protein), or AHC (C+80% amino acid, 20% peptide) for 21 d. Blood and duodenum samples were collected for measurement of serum GI hormones, and pancreatic ${\alpha}$-amylase activity was determined at 900, 1030, 1330, 1630, and 1930 h after feeding on d 21 of treatment. The levels of serum cholecystokinin (CCK) and secretin in the IC treatment group were higher compared to the other treatment groups (p<0.05). In addition to the changes in CCK and secretin levels upon IC treatment, the pancreatic ${\alpha}$-amylase activity in the duodenum was higher in the IC group compared to the control diet group (p<0.05). The response of serum ghrelin to IC and AHC treatment was in accordance with the response of serum secretin. The level of peptide fragments flowing in the duodenum was higher in the IC treatment group than the other treatment groups (p<0.05). In conclusion, this study demonstrated that an increase in duodenal CCK and secretin upon IC oral administration increased pancreatic ${\alpha}$-amylase secretion. In addition, ghrelin may be associated with GI hormone secretion in Korean native steers.

• Food Science of Animal Resources
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• v.39 no.5
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• pp.725-741
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• 2019

In the current study, we first investigated a method for directly transforming lactose into galacto-oligosaccharides (GOS) for manufacturing low-lactose and GOS-enriched skim milk (GSM) and then evaluated its prebiotic potential by inoculating five strains of Bifidobacterium spp. In addition, fermented GSM (FGSM) was prepared using a potentially probiotic Lactobacillus strain and its fermentation characteristics and antioxidant capacities were determined. We found that GOS in GSM were metabolized by all five Bifidobacterium strains after incubation and promoted their growth. The levels of antioxidant activities including radical scavenging activities and 3-hydroxy-3-methylglutaryl-CoA reductase inhibition rate in GSM were significantly increased by fermentation with the probiotic Lactobacillus strain. Moreover, thirty-nine featured peptides in FGSM was detected. In particular, six peptides derived from ${\beta}$-casein, two peptides originated from ${\alpha}s_1$-casein and ${\kappa}$-casein were newly identified, respectively. Our findings indicate that GSM can potentially be used as a prebiotic substrate and FGSM can potentially prevent oxidative stress during the production of synbiotic fermented milk in the food industry.

• Journal of Dairy Science and Biotechnology
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• v.31 no.1
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• pp.67-73
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• 2013

Food allergy is defined as adverse reactions toward food mediated by aberrant immune mechanisms. Cow's milk allergy is one of the most common food allergies in childhood. This allergy is normally outgrown in the first year of life, however 15% of allergic children remain allergic. Cow's milk allergy seem to be associated with casein (${\alpha}_{s1}$-CN), ${\beta}$-lactoglobulin and whey protein. In addition to this, many other milk proteins are antigenic and capable of inducing immune responses. Various food processing affects the stability, structure and intermolecular interactions of cow milk proteins, as a result reduction the allergenic capacity. Heating, hydrolysis, chemical, proteolytic and other processes such as gamma-ray irradiation, high pressure, using probiotics treatments of milk to obtain hypoallergenic milk have been developed to reduce allergic reactions.

• Journal of Pharmaceutical Investigation
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• v.20 no.4
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• pp.209-215
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• 1990

The activities of s-amylase, ${\alpha}-amylase$ and protease of three combination products containing digestive enzymes, antacids and herbal drugs on the Korean market were estimated. The effects of antacids and herbal drugs on the activities of digestive enzymes were investigated. Starch-saccarifying activity of s-amylase, starch-dextrinizing activity of ${\alpha}-amylase$ and protein-peptic activity of protease were estimated by Somogy, Mc'Credy, and Casein-Folin method, respectivley. The optimal pH of s-amylase, ${\alpha}-amylase$ and protease were pH 5.0, 4.8 and 7.0, rcspectively. The digestive activities at optimal pH continued about eight hours. The digestive activities of individual enzymes were reduced to 40-90% by antacids and were affected somewhat positively or negatively by herbal drugs. Enzyme activities of the combination products were also affected by pH and reaction time.

• Journal of Dairy Science and Biotechnology
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• v.27 no.2
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• pp.7-16
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• 2009

Appenzeller cheese samples were prepared by addition of 0.5, 1.0, and 2.0% green tea (Camellia sinensis, CS) powder and control cheese. We examined various quality characteristics of the novel cheese, such as viable-cell counts, pH, water-soluble nitrogen (WSN), non-casein nitrogen (NCN), non-protein nitrogen (NPN), and catechin level during maturation for 16 weeks at $14^{\circ}C$. To develop a Korean natural cheese containing green tea powder, we also analyzed the changes in the polyacrylamide gel electrophoresis pattern, chemical composition, and sensory qualities. The viable cell counts of the samples were not significantly different. Until the $3^{rd}$ week, the pH of the CS cheese decreased with an increase in the maturation time. However, the pH gradually increased by the $12^{th}$ week, while WSN, NCN, NPN also increased. The WSN, NCN, NPN, and catechin values for the CS cheese samples were significantly higher than the values for the control cheese. The polyacrylamide gel electrophoretic pattern of caseins for the CS cheese indicated that this cheese degraded more rapidly than the control cheese did. In the sensory evaluation, cheese with 1.0% CS powder showed the highest scores in taste and appearance and good scores in flavor and texture. These results indicate that 1.0% CS is the optimal value for addition to cheese, and cheese containing 1.0% CS shows good physiological properties and reasonably high overall sensory acceptability.