• 한국유가공학회:학술대회논문집
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• 1998.05a
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• pp.22-29
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• 1998

Various peptides derived from food are among the most potent physiologically active agents known, and include anticancer peptides, angiotensin converting enzyme(ACE) inhibitor exhibiting antihypertension action, opioid peptides, antithrombotic peptides, hypocholesterolemic peptides, immunomodulators, calcium absorption enhancers, and other peptides. Hydrophobic peptides extracted from a Cheddar-type cheese slurry were fractionated by gel chromatography and repeated HPLC. A peptide fraction from HPLC showed high cytotoxicity on the tumor cell lines such as a human colon carcinoma, and comprised of Tyr, Ser, Leu, Gly, and others. Hypocholesterolemic peptides were isolated from peptic hydrolyzates of casein and soy proteins. Macropeptides of 1,000${\sim}$5,000 dalton were effective on reducing the cholesterol level of mouse serum. Peptides showing high Krigbaum hydrophobicity and ANS surface hydrophobicity resulted in high hypocholesterolemic effect and fecal steroid concentrations. Caseinomacropeptides (CMP) were isolated from whey powder and treated with soluble and immobilized trypsin to obtain antithrombotic peptides. One fraction from the CMP hydrolyzed with immobilized trypsin for 24h exhibited high antithrombotic activity with 52.5% inhibition of platelet aggregation. These results suggested that peptides from various milk products could be utilized as a good bioactive agents for developing health functional foods.

• Journal of Dairy Science and Biotechnology
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• v.42 no.2
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• pp.35-47
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• 2024

Milk exosomes contain several bioactive molecules, including lipids, proteins, and miRNAs, which enhance immune response. This study aimed to assess the resistance effects of bovine colostrum exosomes (BCEs) on pathogenic microbial infections in a Caenorhabditis elegans model. BCEs have been shown to enhance the protective response of C. elegans to pathogenic bacterial infections. Our study revealed that BCE extended the lifespan of worms compared to control OP50 worms. In addition, nematode colostrum exosomes promoted nematode resistance to four pathogenic bacteria and prolonged their lifespan in a killing assay. In contrast, mature milk-derived exosomes (BME) did not affect the resistance and lifespan of nematodes exposed to pathogenic bacteria. BCE exposure extended the lifespan of C. elegans against pathogenic infections by stimulating the innate immune response and increasing antimicrobial protein expression. Using biological process-related gene ontology (GO) enrichment analysis, the significantly upregulated GO terms related to C. elegans immunity in BCE-exposed C. elegans included defense, innate immunity, and immune responses. This study demonstrated that BCE enhanced the host defense of C. elegans to prolong its lifespan, thereby suggesting a new natural product against infection by pathogenic bacteria.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.6
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• pp.1012-1022
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• 2020

Objective: Caseins and fatty acids of milk are synthesized and secreted by the epithelial cells of the mammary gland. All-trans retinoic acid (ATRA), an active metabolite of vitamin A, has been shown to promote mammary development. This study was conducted to determine the effect of ATRA on casein synthesis and fatty acid composition in MAC-T cells. Methods: MAC-T cells were allowed to differentiate for 4 d, treated with ATRA (0, 1.0, 1.5, and 2.0 μM), and incubated for 3 d. We analyzed the fatty acid composition, the mRNA expression of casein and fatty acid synthesis-related genes, and the phosphorylation of casein synthesis-related proteins of MAC-T cells by gas chromatography, quantitative polymerase chain reaction, and western blotting, respectively. Results: In MAC-T cells, ATRA increased the mRNA levels of α_S1-casein and β-casein, janus kinase 2 (JAK2) and E74-like factor 5 of the signal transducer and activator of transcription 5 β (STAT5-β) pathway, ribosomal protein S6 kinase beta-1 (S6K1) and eukaryotic translation initiation factor 4E binding protein 1 of the mammalian target of rapamycin (mTOR) pathway, inhibited the mRNA expression of phosphoinositide 3-kinase and eukaryotic initiation factor 4E of the mTOR pathway, and promoted the phosphorylation of STAT5-β and S6K1 proteins. Additionally, ATRA increased the de novo synthesis of fatty acids, reduced the content of long-chain fatty acids, the ratio of monounsaturated fatty acids to saturated fatty acids (SFA), the ratio of polyunsaturated fatty acids (PUFA) to SFA, and the ratio of ω-6 to ω-3 PUFA. The mRNA levels of acetyl-CoA carboxylase 1, fatty acid synthase, lipoprotein lipase, stearoyl-CoA desaturase, peroxisome proliferator-activated receptor gamma, and sterol regulatory element-binding protein 1 (SREBP1) were enhanced by ATRA. Conclusion: ATRA promotes the synthesis of casein by regulating JAK2/STAT5 pathway and downstream mTOR signaling pathway, and it improves the fatty acid composition of MAC-T cells by regulating SREBP1-related genes.

• Journal of Dairy Science and Biotechnology
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• v.31 no.2
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• pp.171-177
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• 2013

The dairy industry has consistently grown via the expansion of dairy-based food categories. Dairy product consumption is stable since the nutrient composition in dairy products is ideal for human health. However, dairy products are highly susceptible to food-borne pathogens. Controlling the safety of dairy products is thus important when considering the nutrient-rich matrix of this food category. Currently, immunoassays or molecular biology techniques have been used to evaluate the safety of dairy products in Korea. These methods are based on the detection of proteins and thus have low reproducibility and sensitivity. Recent techniques to detect food-borne pathogens have focused on genetic analyses. Rapid detection methods for food-borne pathogens in milk and dairy products using polymerase chain reaction (PCR) techniques, such as conventional PCR, real-time PCR, repetitive sequence-based (rep)-PCR, PCR-denaturing gradient gel electrophoresis (DGGE), and digital PCR, are reviewed in this article. The aim of this review was to contribute knowledge of the relationship between microflora and the quality of dairy products. This study will also assist in the immediate monitoring of food-borne pathogens in milk and dairy products when an outbreak related to this food category occurs.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2002.11a
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• pp.71-71
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• 2002

Promoters for milk proteins have been used far producing transgenic animals due to their temporal and spatial expression patterns. ${\beta}$-casein, a calcium-sensitive casein, is a major milk protein that corresponds ca. 30 per cent of total milk protein. Expression of ${\beta}$-casein is controlled by lactogenic hormones such as prolactin (PRL), composite response elements (CoREs) and transcription factors. CoREs are clusters of transcription factor binding sites containing both positive and negative regulatory elements. ${\beta}$-casein gene promoter contains various regions (CoREs) for gene transcription. We analyzed the promoter region by mutagenesis using exonuclease III and linker-scanning. Transcription control elements usually are positioned in 5'-flanking region of the gene. However, in some cases, these elements are located in other regions such as intron 1. The nucleotide sequences of ${\beta}$-casein promote. region has been reported (E12614). However, the properties of the promoter is not yet clear. In this study, we plan to investigate the properties of cis-regulating elements of porcine ${\beta}$-casein by mutation analysis and expression analysis using dual-luciferase repoter assay system.

• Korean Journal of Community Nutrition
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• v.22 no.5
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• pp.387-400
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• 2017

Objectives: This study was designed to find out factors that are needed to be improved for the Buddhist training environment of Sramanera Sramanerika monks, who have been newly adapted for their life style after becoming a monk, and to provide basic data for the development of the standard diet in Buddhist temples. Methods: A self-administered questionnaire was applied to 365 Sramanera Sramanerika monks at 11 Buddhist monk universities. The questionnaire was designed to investigate their dietary habits, dietary evaluation, satisfaction of food service, and food preferences. Results: The study population consisted of 52.6% men, and 47.4% women. The subjects who had a vegetarian diet before joining the Buddhist priesthood were 27.7% women, and 13.5% men (p<0.01). 42.2% of the total subjects felt that they are healthy now and 19.4% felt weak. The most difficulty of dieting adaptation as soon as entering the priesthood was the strict diet rules (42.9%). The subjects considered health or nutrition (40.0%) highly when having meals. 94.8% women, 84.1% men ate breakfast every day (p<0.001). Women (55.4%) frequently ate snacks more than men (26.6%) (p<0.001). The results of the dietary evaluation indicated that the intake of milk, soy milk or dairy products and beans or tofu received lower than 3 points and women had lower point result than men (p<0.001). Foods with higher preference were grilled mushrooms, grilled laver, miso stew, sweet and sour mushrooms, steamed tofu with seasoning. Conclusions: Women were more interested in their health than men but they also required to improve the nutritional eating habits. It appeared that the lower intake rates of the calcium containing food (milk and dairy), and proteins (beans and tofu) could result in nutritional imbalance. Therefore, it is necessary to offer food based on the standard menu plan with consideration given to their food preferences in order to maintain their health and desirable dietary habits.

• Korean Journal of Food Science and Technology
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• v.18 no.3
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• pp.221-225
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• 1986

The possibility of by-products utilization in a sausage formulation was studied using Linear Programming. Among constraints groups (1: moisture and meat content, 1 + heart, 1 + organ, 1 + head, 1 + heart + backfat, 1 + heart + organ, 1 + heart + head, 1 + heart + head + backfat), the group in which moisture and meat content, and the use of heart and organ were considered appeared to give the least-cost formulation. The groups where the use of backfat was considered resulted in higher-cost formulations. However, if the formulation contains bindery and extenders such as vegetable proteins or milk proteins which are not limited in use antler the Korean regulation, the result would be different from that obtained here.

• Food Science of Animal Resources
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• v.37 no.6
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• pp.940-947
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• 2017

Goat milk has a protein composition similar to that of breast milk and contains abundant nutrients, but its use in functional foods is rather limited in comparison to milk from other sources. The aim of this study was to prepare a goat A2 ${\beta}$-casein fraction with improved digestibility and hypoallergenic properties. We investigated the optimal conditions for the separation of A2 ${\beta}$-casein fraction from goat milk by pH adjustment to pH 4.4 and treating the casein suspension with calcium chloride (0.05 M for 1 h at $25^{\circ}C$). Selective reduction of ${\beta}$- lactoglobulin and ${\alpha}_s$-casein was confirmed using sodium dodecyl sulphate-polyacrylamide gel electrophoresis and reverse-phase high-performance liquid chromatography. The hypoallergenic property of A2 ${\beta}$-casein fraction was examined by measuring the release of histamine and tumor necrosis factor alpha from HMC-1 human mast cells exposed to different proteins, including A2 ${\beta}$-casein fraction. There was no significant difference in levels of both indicators between A2 ${\beta}$-casein treatment and the control (no protein treatment). The A2 ${\beta}$-casein fraction is abundant in essential amino acids, especially, branched-chain amino acids (leucine, valine, and isoleucine). The physicochemical properties of A2 ${\beta}$-casein fraction, including protein solubility and viscosity, are similar to those of bovine whole casein which is widely used as a protein source in various foods. Therefore, the goat A2 ${\beta}$-casein fraction may be useful as a food material with good digestibility and hypoallergenic properties for infants, the elderly, and people with metabolic disorders.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.3
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• pp.357-364
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• 2014

The study evaluated replacement of Egyptian berseem clover (BC, Trifolium alexandrinum) with spent rice straw (SRS) of Pleurotus ostreatus basidiomycete in diets of lactating Baladi goats. Nine lactating homo-parity Baladi goats (average BW $23.8{\pm}0.4$ kg) at 7 d postpartum were used in a triplicate $3{\times}3$ Latin square design with 30 d experimental periods. Goats were fed a basal diet containing 0 (Control), 0.25 (SRS25) and 0.45 (SRS45) (w/w, DM basis) of SRS. The Control diet was berseem clover and concentrate mixture (1:1 DM basis). The SRS45 had lowered total feed intake and forages intake compared to Control. The SRS25 and SRS45 rations had the highest digestibilities of DM (p = 0.0241) and hemicellulose (p = 0.0021) compared to Control which had higher (p<0.01) digestibilities of OM (p = 0.0002) and CP (p = 0.0005) than SRS25 and SRS45. Ruminal pH and microbial protein synthesis were higher (p<0.0001) for SRS25 and SRS45 than Control, which also had the highest (p<0.0001) concentration of TVFA, total proteins, non-protein N, and ammonia-N. All values of serum constituents were within normal ranges. The Control ration had higher serum globulin (p = 0.0148), creatinine (p = 0.0150), glucose (p = 0.0002) and cholesterol (p = 0.0016). Both Control and SRS25 groups had the highest (p<0.05) milk (p = 0.0330) and energy corrected milk (p = 0.0290) yields. Fat content was higher (p = 0.0373) with SRS45 and SRS25 groups compared with Control. Replacement of BC with SRS in goat rations increased milk levels of conjugated linoleic acid and unsaturated fatty acids compared with Control. It was concluded that replacing 50% of Egyptian berseem clover with SRS in goat rations improved their productive performance without marked effects on metabolic indicators health.

• Korean Journal of Food Science and Technology
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• v.46 no.2
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• pp.165-172
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• 2014

Mixed fermentation of cow milk was performed by sequential co-cultures with Bacillus subtilis and Lactococcus lactis. After a first fermentation step with B. subtilis for 6 h, the number of viable cells increased to $2.5{\times}10^8$ CFU/mL. The second fermentation step with L. lactis resulted in increased viable cells $1.09{\times}10^{10}$ CFU/mL for 3 days and increased acidity. However, the number of viable B. subtilis cells was decreased greatly to $5{\times}10^1$ CFU/mL following fermentation with L. lactis. Milk proteins were markedly hydrolyzed by the first fermentation after 2 h, and the second fermentation induced curd formation in milk. However, after 4 h, the first fermentation resulted in higher whey separation and 80 mg% tyrosine content. Gamma-aminobutyric acid (GABA) production was dependent upon the degree of protein hydrolysis by first fermentation. Second fermentation resulted in 0.14% GABA. The milk fermented by B. subtilis indicated the rough surface of yogurt depended upon the degree of protein hydrolysis. In conclusion, set-type yogurt was efficiently produced by co-culturing of milk, and fortifying with peptides, GABA, and probiotics.