• 한국동물위생학회지
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• 제36권3호
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• pp.217-222
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• 2013

In this study, we compared nutrient content emphasized on labelling of processed milks with that of whole milks and evaluated how well they conform to labelling standard. A total of 98 samples (33 whole milks, 28 calcium fortified milks, 30 low-fat milks and 7 lactose hydrolyzed milks) were collected in hypermarkets in Seoul from August 28 to August 30 in 2012. Calcium, fat and lactose contents were tested in the samples. Calcium contents ranged 102.2~113.0 mg/100 mL in whole milks and 120.1~337.8 mg/100 mL in calcium fortified milks. The level of calcium contents in fortified milks ranged very broad. Accordingly, the standard of calcium contents on fortified milks will be required. Fat contents ranged 3.1~3.9 g/100 mL in whole milks and 0.1~1.9 g/100 mL in low-fat milks. The average of fats content in low-fat milks was nearly one third than whole milks. Lactose contents was ranged 4.6~5.1 g/100 mL in whole milks and not detected in lactose hydrolyzed milks. All of processed milks were suitable to processing standard and labelling standard. But nutrition claims often used on processed milk such as "High" or "Low" were not adequate to indicate the exact nutrient content, which is a cause of the confusion for milk product labelling to consumers. We need a lot of research about nutrient labelling that can deliver appropriate and understandable information to customers.

• Asian-Australasian Journal of Animal Sciences
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• 제14권11호
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• pp.1549-1554
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• 2001

The application of rumen undegradable intake protein (UIP) on lactating dairy goats was studied. Thirty 2-year-old lactating dairy goats were selected and assigned to dietary treatments begun from the third week to the fourth month postpartum. Experimental diets were formulated into three, low (32% CP), med (35% CP) and high (38% CP), iso-nitrogenous (16% CP) and iso-energetic ($NE_L$ 1.68 Mcal/kg) UIP levels. Results showed that feed intake was not significantly different among the treatment groups. The milk yield in the High UIP group (3.17 kg) was significantly higher than the med (2.95 kg) and low UIP (2.45 kg) groups (p<0.05). The milk compositions, milk fat, milk lactose and milk solids-non-fat (SNF) showed no significant differences among the three treatment groups. The milk protein however was significantly (p<0.05) lower in the low UIP than in the other treatment groups. The milk urea-N was significantly (p<0.05) higher in the low UIP than in the other treatment groups. The mean serum aspartate amino transferase (AST), urinary-N and total protein concentrations were significantly (p<0.05) lower in the high and the med UIP groups than in the low UIP group.

• Journal of Dairy Science and Biotechnology
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• 제28권1호
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• pp.53-59
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• 2010

The milk product is one of the major foods which provide calcium for nutritional requirement. In addition to calcium, it supplies diverse nutrients including protein, potassium, vitamin A, vitamin $B_1$, and vitamin $B_2$. Adequate calcium intake throughout lifetime ensures optimum bone density and prevents osteoporosis in old age by reducing loss of bone mineral during growth and aging. The nutritional deficiency of calcium intake and spreading of osteoporosis in Korean population accentuated necessity of adequate calcium intake through milk consumption. Obstruction of milk consumption due to lactose intolerance should be overcome by educational programs for adequate milk consumption and low-lactose milk product developments. Consumption of milk products was reported to prevent high blood pressure in clinical studies and epidemiological investigations. As the feeding of milk increased, the body weight and fat of animal decreased in animal studies. The epidemiological investigations revealed that there was a negative correlation between the amount of milk consumption and the body fat. When calcium was provided as dietary supplement in the clinical trials, the body weight and body fat of subjects decreased. When calcium was particularly supplied as a part of milk, the body weight reduction rate was augmented. Calcium, vitamin D, and conjugated linoleic acid have been reported to exert a role in reducing cancer. The paramount importance of milk in nutrition as a source of calcium and other invaluable nutrients emphasizes consistent supply of milk products to adults as well as adolescents by dairy industry.

• 한국축산식품학회지
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• 제39권5호
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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.

• Near Infrared Analysis
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• 제2권1호
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• pp.59-66
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• 2001

Nowadays, medical diagnostics is efficiently supported by clinical chemistry and near infrared spectroscopy is becoming a new dimension, which has shown high potential to provide valuable information for diagnosis. The investigation was carried out to study the influence of mammary gland inflammation, called mastitis, on cow´s milk spectra and milk composition measured by near infrared spectroscopy (NIRS). Milk somatic cell counts (SCC) in milk were used as a measure of mammary gland inflammation. Naturally occurred variations with milk composition within lactation and in the process of milking were included in the experimental design of this study. Time series of unhomogenized, raw milk spectral data were collected from 3 cow along morning and evening milking, for 5 consecutive months, within their second lactation. In the time of the trial, the investigated cows had periods with mammary gland inflammation. Transmittance spectra of 258 milk samples were obtained by NIRSystem 6500 spectrophotometer in 1100-2400 nm region. Calibration equations for the examined milk components were developed by PLS regression using 3 different sets of samples: samples with low somatic cell count (SCC), samples with high SCC and combined data set. The NIR calibration and prediction of individual cow´s milk fat, protein, and lactose were highly influenced by the presence of mil samples from animals with mammary gland inflammation in the data set. The best accuracy of prediction (i.e. the lower SEP and the higher correlation coefficient) for fat, protein and lactose was obtained for equations, developed when using only “healthy” samples, with low SCC. The standard error of prediction increased and correlation coefficient decreased significantly when equations for low SCC milk were used to predict examined components in “mastitis” samples with high SCC, and vice versa. Combined data set that included samples from healthy and mastitis animals could be used to build up regression models for screening. Further use of separate model for healthy samples improved milk composition measurement. Regression vectors for NIR mild protein measurement obtained for “healthy” and “mastitic” group were compared and revealed differences in 1390-1450 nm, 1500-1740 nm and 1900-2200 nm regions and thus illustrated post-secretory breakdown of milk proteins by hydrolytic enzymes that occurred with mastitis. For the first time it has been found that monitoring the spectral differences in water bands at 1440 nm and 1912 nm could provide valuable information for inflammation diagnosis.

• Journal of Microbiology and Biotechnology
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• 제14권3호
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• pp.584-592
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• 2004

A thermostable $\beta$-glycosidase gene, tfi $\beta$-gly, was cloned from the genomic library of Thermus filiformis Wai33 A1. ifi $\beta$-gly consists of 1,296 bp nucleotide sequence and encodes a polypeptide of 431 amino acids. It shares a strong amino acid sequence similarity with the $\beta$-glycosidases from other Thermus spp. belonging to the glycosyl hydrolase family 1. In the present study, the enzyme was overexpressed in Escherichia coli BL21 (DE3) using the pET21b(+) vector system. The recombinant enzyme was purified to homogeneity by heat treatment and a $Ni^{2+}$-affinity chromatography. Polyacrylamide gel electrophoresis (PAGE) showed that the recombinant Tfi $\beta$-glycosidase was a monomeric form with molecular mass of 49 kDa. The temperature and pH range for optimal activity of the purified enzyme were 80- $90^{\circ}C$ and 5.0-6.0, respectively. Ninety-three percent of the enzyme activity was remained at $70^{\circ}C$ after 12 h, and its half-life at $80^{\circ}C$ was 6 h, indicating that Tfi $\beta$-glycosidase is highly thermostable. Based on its K_m$, or $K_{cat}K_m$, ratio, Tfi $\beta$-glycosidase appeared to have higher affinity for $\beta$-D-glucoside than for $\beta$-D-galactoside, however, $K_{cat} for \beta$-D-galactoside was much higher than that for $\beta$-D-glucoside. The activity for lactose hydrolysis was proportionally increased at $70^{\circ}C$ and pH 7.0 without substrate inhibition until reaching 250 mM lactose concentration. The specific activity of Tfi TEX>$\beta$-glycosidase on 138 mM lactose at $70{^\circ}C$ and pH 7.0 was 134.9 U/mg. Consequently, this newly cloned enzyme appears to have a valuable advantage of conducting biotechnological processes at elevated temperature during milk pasteurization in the production of low-lactose milk.

• 대한영양사협회학술지
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• 제11권2호
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• pp.242-250
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• 2005

The objective of this study is to determine the effectiveness of 4-month milk consumption in the prevention of osteoporosis in elderly women living in Asan. Subjects included 277 women age over 65 years were divided into control (n=111) and milk (n=166) groups. For those in the milk group, one cup (200ml) of partially lactose-digested low-fat milk was provided everyday for 4 months. Each subject was interviewed to assess food intake by 24-h recall method before and after milk supplementation. Prevalence of osteoporosis was determined by WHO criteria with calcaneus bone mineral density (BMD) measured by quantitative ultrasound (QUS) on left heel. After 4 months, the nutrient intake levels of control did not change while intakes of energy, protein, calcium, phosphorous, riboflavin, pyridoxin, niacin and folic acid were significantly increased in milk group. No significant changes were observed in anthropometric, and BMD in both control and milk groups. T-score of milk group, however, was significantly increased after 4 month milk consumption. Prevalence of osteoporosis was increased (27% to 32%) in control group while that of milk group was decreased (32% to 30%). When BMD and t-score changes after 4 months of milk consumption were compared between those with low baseline calcium intake and high calcium intake subjects in the milk group, BMD and t-score were significantly improved in the low baseline calcium intake group. We conclude that one cup a day milk consumption for a relatively short period of 4 months can prevent further bone loss and significantly improve intakes of both macro and micro-nutrients of elderly women.

• 한국축산식품학회지
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• 제33권3호
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• pp.369-376
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• 2013

Milk is well known to be rich in some nutrients such as protein, calcium, phosphorus, and vitamins. In particular, absorption and bioavailability of calcium receive lots of attention because calcium is very little absorbed until it is changed to the ionized form in the intestine. In this study, concentration of the soluble calcium was determined in the commercial bovine milk products, which were processed by different heat-treatment methods for pasteurization. As for general constituents, lactose, fat, protein, and mineral were almost same in the liquid milk products by different processors. Ultrafiltration of the skimmed milk caused little change in the permeate as for lactose content but both fat and protein decreased. pH values ranges from 6.57-6.62 at room temperature and slightly increase after centrifugation, 10,000 g, 10 min. Rennet-coagulation activity was the lowest in the ultra high temperature (UHT-)milk compared to the low temperature long time (LTLT-) and high temperature short time (HTST-)milk products. Each bovine milk products contains 1056.5-1111.3 mg/kg of Ca. The content of sulfhydryl group was the lowest in raw milk compared to the commercial products tested. For the skimmed milks after ultrafiltration with a membrane (Mw cut-off, 3 Kd), soluble Ca in the raw milk was highest at 450.2 mg/kg, followed by LTLT-milk 336.4-345.1 mg/kg, HTST-milk 305.5-313.3 mg/kg, UHT-milk 370.3-380.2 mg/kg in the decreasing order. After secondary ultrafiltration with a membrane (Mw cut-off, 1 kD), total calcium in raw milk had a highest of 444.2 mg/kg, and those in the market milk products. As follow: UHT-milk, 371.3 to 378.2 mg/kg; LTLT-milk, 333.3 to 342.2 mg/kg; HTST-milk 301.9 to 311.2 mg/kg in a decreasing order.

• Journal of Dairy Science and Biotechnology
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• 제33권3호
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• pp.223-229
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• 2015

Milk is a food with high nutritional value as it contains abundant water, proteins, vitamins, lactose, fat, minerals, enzymes, etc. However, in order to make milk suitable for intake, it should be thermally treated to eliminate microbiologically hazardous factors. Heat treatment is an essential sanitation process for milk, but various precautions must be taken in order to process and preserve it. Therefore, various techniques should be developed to minimize the nutrient loss and to ensure that milk is safe for consumption, conservation, and distribution. However, the existing thermal pasteurization methods are harmful and increase the nutrient loss; moreover, no new thermal pasteurization methods are being researched that are safe for the human health and minimize the nutrient loss. Hence, this study aims to review new processes for thermal (low temperatures) and no thermal pasteurization methods that can minimize the nutrient loss during milk pasteurization.

• Animal Bioscience
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• 제35권1호
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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.