• 한국축산식품학회지
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• 제31권6호
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• pp.827-833
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• 2011

The objective of this study was to develop a fluorogenic real-time PCR-based assay for detecting and quantifying amounts of cow milk in cow/goat milk mixtures or goat milk products. In order to quantify the exact amount of cow milk in cow/goat raw milk mixtures and commercial goat milk products, it was necessary to achieve quantitative extraction of total genomic DNA from the raw milk matrix. Both mammalian-specific PCR and cow-specific PCR were performed. A cow-specific 252 bp band obtained from the raw cow milk and raw goat milk mixtures, commercial goat milk, and two goat milk powders was identified, along with the relationship between the cow milk amount and band intensity of the electrophoresis image. The detection threshold was found to be 0.1%. The expression of cow's 12S rRNA in the cow/goat milk mixtures, commercial goat milk, and two goat milk powders was identified. The expression quantity of the milk 12S rRNA increased with increasing ratios of the cow/goat milk mixtures. Using these calibrated relative expression levels as a standard curve in the cow/goat raw milk mixtures, the contents of cow milk were 1.8% in the commercial goat milk, 9.6% in goat milk powder A, and 11.6% in goat milk powder C. However, cow milk was not detected in goat milk powder B.

• Asian-Australasian Journal of Animal Sciences
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• 제23권10호
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• pp.1369-1379
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• 2010

This study investigated purification and milk-clotting activity of the enzymes produced by Bacillus subtilis var, natto and Rhizopus oligosporus compared with that of commercial rennet. The clotting time, viscosity, tension and microstructure of the curd and electrophoretic patterns of milk proteins were determined. The milk-clotting activity/proteolytic activity ratios (MCA/PA ratio) of B. subtilis, R. oligosporus and commercial rennet were also compared. The results revealed that the curd formed by the commercial rennet had the highest viscosity and curd tension and the shortest clotting time among the three enzymes. However, curd produced by Rhizopus enzymes was ranked as second. From the MCA/PA ratio and electrophoretogram analyses it could be concluded that the enzyme produced by B. subtilis had the highest proteolytic activity, while the commercial rennet had the highest milk-clotting activity. Observations of microstructures of SEM showed that the three-dimensional network for curd formed by commercial rennet was denser, firmer and more smooth. The milk-clotting activity, specific activity, purification ratio and recovery of the purified enzymes produced by both the tested organisms were also determined with ion exchange chromatography and gel filtration.

• 한국식품과학회지
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• 제12권3호
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• pp.158-164
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• 1980

시판(市販) 우유 및 분유를 시료(試料)로 하여 관능(官能) 검사법(檢査法)에 의한 품질(品質) 평가(評價)를 실시하여 다음과 같은 결과(結果)를 얻었다. 1. 시판(市販) 우유에 대한 순위(順位) 시험(試驗) 결과(結果), 5개(個) 회사(會社) 제품별(製品別) 시료(試料)의 품질(品質) 및 기호도(嗜好度)에 있어서 5% 수준(水準)에서 유의적(有意的)인 차이(差異)가 인정(認定)되지 않았다. 2. 채점(採點) 시험(試驗)에 의한 시판(市販) A우유의 shelf life 검사(檢査) 결과(結果), $0{\sim}5^{\circ}C$와 $10^{\circ}C$에서는 3일간(日間), $20^{\circ}C$, $30^{\circ}C$에서는 1일(日) 정도 품질(品質)이 유지되었다. 3. 시판(市販) C분유(粉乳)에 대한 희석(稀釋) 검사(檢査) 결과(結果), 희석(稀釋) 계수(係數)가 20.0으로 시료(試料) 분유(粉乳)의 품질(品質)은 비교적 양호(良好)하였다. 4. 시판(市販) 우유에 대한 풍미(風味) 묘사(描寫) 시험(試驗) 결과(結果), 각 우유의 풍미(風味)는 종합적으로 우수하게 평가(評價)되었으며, 구성(構成) 풍미(風味)의 강도(强度)는 회사(會社) 제품(製品) 별(別)로 다소(多少)의 차이(差異)를 나태내었다. 5. 시판(市販) 5개(個) 회사(會社) 제품(製品) 별(別) 우유의 풍미(風味)에 대한 차이(差異) 식별(識別) 시험(試驗)이나 묘사(描寫) 시험(試驗)에서는 뚜렷한 차이(差異)를 나타내었으나 순위(順位) 시험(試驗)에서는 유의적(有意的)인 차이(差異)가 인정(認定)되지 않았다.

• Journal of Nutrition and Health
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• 제29권9호
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• pp.1042-1048
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• 1996

In order to investigate heating rate of commercial milk products in korean market, lactulose content and availability of calcium and ascorbic acid were measured. The pH range for raw and commercial milk was 6.5-6.75, and protein content was 2.5-3.13%. The acid degree value (。SH)showed between 5.3 and 7.1. There were no differences in pH, protein and acid degree among 3 types of milk. The portion ionic Ca content in UHT-milk(32.4%) and pasteurized milk (27%) increased significantly in comparison with raw milk (4.6%). Pasteurization led to loss of 20% ascorbic acid, and losses of UHT-treatment are approximately twice as high. Significant differences of lactulose content between UHT milk and pasteurized milk were observed. Some of UHT milk products showed very high value of lactulose content like sterilized milk. It is well known that the stress caused by indirect UHT treatment is slightly higher compared with the direct process. The results in this experiment suggested that most of UHT milk in korean market may be treated by indirect UHT method. In oder to keep the adventages of milk component, the heating methods of milk have to be reconsidered.

• Journal of Nutrition and Health
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• 제30권8호
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• pp.904-910
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• 1997

Evaluation of soy milk as an iron-rich milk substitute was conducted by feeding commercial soy milk , cow milk and mixed formula(soy and cow milk) to Wistar rats for 8 weeks. Body weight gains were significantly lower in the soy milk and mixed formula groups. Hematocrit, serum iron concentration and TIBC (total iron binding capacity) were measured to determine the iron status of the rats. In these respects, the iron status of the soy milk group was normal. Both serum iron concentration and TIBC as well as hematocrit were abnormal in the cow milk group , which is indictive of severe iron deficiency . Although hematocrit was normal in the mixed formula group, serum iron concentration was lightly low. The work capacities of each group were correlated with serum iron concentration and tIBC rather than hematocrit. The running distance of the soy milk group was about 10 -fold longer than that of the cow milk group. Soy milk may be considered an iron- rich substitute for cow milk due to its higher iron content and bioavailability.

• 한국조리학회지
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• 제24권2호
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• pp.63-70
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• 2018

In this study, the fatty acid content and quality characteristics of the massless enegy treated commercial milk products stored at $30^{\circ}C$ were investigated. The pH of pasteurized milk decreased significantly. UHT milk showed also significant decrease in pH to 4.70~5.72 on the 8th day of storage which was higher than control even there was no significant differences. The acidity of pasteurized milk decreased significantly from the 2nd day of storage to 0.13~0.65% in treatments and control and control was 0.94% at the 8th day of storage and 0.35% in the treatment of ultra high temperature milk. The solid content of pasteurized milk was $7.5^{\circ}Bx$ at 1 day after storage, which showed significant differences from the $11.2^{\circ}Bx$ in the treatment. Pasteurized milk showed more bacterial growth in the treatment than in the control. After 4 days of storage, there was no bacterial count in pasteurized milk but it increased significantly $1.9{\times}10^8$ and $4.5{\times}10^6$ each in UHT milk. Lactic acid bacteria were detected in the curd $2.0{\times}10^6$ in the control and $2.0{\times}10^8$ in the treatment at the 4th day. Palmitic acid content in the saturated fatty acid was the highest at 35.4~41.4% in both pasteurized and ultra high temperature milk. In the UHT milk, linolenic acid was significantly increased to 3.8% in the treatment compared with 2.9% in the control at the 4th day of storage. Therefore, commercial ultra high temperature milk with physical treatment to increase beneficial bacteria showed significant difference compared to the control after 5 days of storage in this experiment.

• 한국임상수의학회지
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• 제33권5호
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• pp.274-277
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• 2016

To determine the concentrations of commercial milks and the effect of different teat dipping methods on iodine concentrations of bulk tank milk, iodine concentration was analyzed by inductively coupled plasma mass spectrometry (ICP-MS). The 59 bulk tank milk samples were collected. The 8 brands of commercial whole milk and 5 brands of commercial organic milk were purchased. The iodine concentrations of bulk tank milks of 59 dairy farms were in the range from 42.7 to $562.5{\mu}g/L$. The iodine levels of 4 different teat dipping methods with pre-dipping, post-dipping, pre & post-dipping, and non-dipping were $138.9{\pm}41.1$, $200.6{\pm}106.9$, $205.1{\pm}93.2$, and $110.9{\pm}70.4{\mu}g/L$, respectively. No significant difference (P > 0.05) was observed among 4 different teat dipping methods. Iodine concentrations of commercial whole milks were in the range from 149.1 to $210.4(178.8{\pm}22.0){\mu}g/L$, and iodine concentrations of commercial organic milks were in the range from 85.0 to $356.9(214.2{\pm}123.3){\mu}g/L$. Iodine concentrations of commercial milk in Korea are relatively low comparing with those of other countries.

• Asian-Australasian Journal of Animal Sciences
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• 제11권3호
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• pp.255-259
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• 1998

Sixteen Friesian Cows were allocated equally into 4 groups in a $4{\times}4$ Latin square design to evaluate the effects of utilizing bean by-products on the feed intake and milk production. Cows were fed on 4.5% of their body weight fresh alfalfa; the remainder of their requirements were covered by one of 4 experimental concentrate treatments: 1) commercial concentrate (CC), 2) 70% CC + 30% bean hulls (BH), 3) 70% CC + 30% Polished bean (PB) and 4) 70% CC+ 15% BH + 15% PB. Results showed that the inclusion of bean hulls at 30% improved (p<0.05) milk yield, 4% fat corrected milk yield, feed conversion ratio and fat percent of the milk over the other treatments. Feeding cows on a commercial concentrate plus 30% BH or 30% PB or 15% from each of BH and PB decreased the cost of feed per kg milk by 13.6, 2.5 and 1.3 %, respectively, lower than those fed on the commercial concentrate.

• Asian-Australasian Journal of Animal Sciences
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• 제20권10호
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• pp.1525-1538
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• 2007

Because of the increasing evidence of potential benefits of conjugated linoleic acid (CLA) on human health, there is a need to investigate its status in commercial dairies and develop feeding strategies to enhance the content and supply of CLA in milk and milk products. A two-year experiment was conducted to study the status of milk fat c-9, t-11 CLA on four selected commercial dairy farms in Utah (two) and Idaho (two), USA. Farms A and C grazed cows on pasture and supplemented with 7.0 kg/cow per day of their respective grain mixes during summer, while conserved forage and grain mix was fed during winter. Farm B fed a total mixed diet all year, with 10% of diet dry matter as fresh cut pasture during summer. Farm D had 1/3 of its cows grazed on pasture and supplemented with a total mixed diet during summer, while the rest were fed a total mixed diet. All cows in Farm D were fed a total mixed diet during winter. Farms A, B, C, and D had on average 80, 400, 150, and 500 milking cows, respectively, with Holstein or its crosses as the major breed. On a year-round basis, Farms A and C produced milk with 60% or more milk fat c-9, t-11 CLA and transvaccenic acid (TVA) contents than Farm B. Similarly, Farm D produced 30% or more c-9, t-11 CLA and TVA in milk than Farm B. Milk fat content of CLA and TVA was 150-200% more during summer compared with winter. Individual cows varied from 0.16 to 2.22% in milk fat c-9, t-11 CLA contents and 89% of the cows had c-9, t-11 CLA contents between 0.3 and 1.0% of milk fat. Individual cow variation was larger on Farms A and C compared with Farm D, with least variation on Farm B. Variation was larger in summer than in winter. The bulk tank milk c-9, t-11 CLA content varied from 0.27 to 1.35% of milk fat. Cows on Farms A and C produced similar or higher amounts of milk fat c-9, t-11 CLA on a daily basis even though their milk yield was lowest among the dairies. Concentration and supplies of c-9, t-11 CLA and TVA were highest from June through September and lowest from February through April, which should be the months for targeting improvement in the content and supply of milk fat c-9, t-11 CLA and TVA.

• Journal of Microbiology and Biotechnology
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• 제30권12호
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• pp.1870-1875
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• 2020

Probiotics are often infused into functional foods or encapsulated in a supplement form to maintain a healthy balance between the gut microbiota and their host. Because there are milk-based functional foods such as yogurt and cheese on the market, it has been suggested that milk-based probiotics could be incorporated into skim milk proteins in a liquid capsule. Skim milk is mainly composed of casein and whey protein, which create a strong natural barrier and can be used to encapsulate probiotics. In this study, we compared the encapsulated probiotics prepared with milk-based concentrated cell mixtures using commercial probiotics. Probiotic capsules were emulsified with skim milk proteins using vegetable oil to form a double coating layer. The product was heat-stable when tested using a rheometer. The survival rate of the milk-based probiotic cells in the lower gastric environment with bile was significantly higher than commercial probiotics. Thus, milk-encapsulated probiotics exhibited greater efficacy in the host than other types of probiotics, suggesting that the former could be more viable with a longer shelf life under harsh conditions than other form of probiotics. Our findings suggested that, compared with other types of probiotics, milk-based probiotics may be a better choice for producers and consumers.