역사적 고찰로 본 우유 음용 및 건강효과

정충일 ( Choong Il Chung ) 한국유가공기술과학회 2010 Journal of Dairy Science and Biotechnology (JMSB) Vol.28 No.1

Recently some negative opinions on milk, for instance, ``don`t drink, if you want to live long`` ``people who drink milk life-long, they suffer from arteriosclerosis`` or ``milk is not helpful to osteoporosis, because it`s acid food```` etc. are confusing the regular consumers who believe milk is one of the best food, although milk has been used for a longtime since it was proved as the most nutritionally perfect food by many scientific researchers and medical doctors. According to the contents of negative assertion, experiments were carried out mostly targeting western people who are eating bread with butter everyday and taking large quantity of meat & milk, probably 2∼3 times more than asian people. So, the probability of suffering from many diseases like obesity, hypertension, arteriosclerosis etc. is naturally high. Therefore, comparison itself between westerner and asian is not reasonable because of quite different food culture and fat intake far less. Milk has been contributing to the health of human for hundreds years supplying many nutrients, and this kind of contribution will last as long as humankind exist on the earth. However, milk is good source of many functional components, there are some people who can not drink milk. As a nutritionist said, milk is a kind of food, the only problem is quantity, people who can not digest milk can choose another and who want to drink milk, drink it as much as they need. That`s all.

Malthus를 이용한 原乳내의 총균수, 대장균군수, 저온성균수 측정

남은숙(Eun-Sook Nam),정충일(Choong-Il Chung),강국희(Kook-Hee Kang),정동관(Dong Kwan Jeong) 한국식품과학회 1994 한국식품과학회지 Vol.26 No.6

국내 가축에서의 축종별 van gene 타입 분포 및 유전형 특성

강현미 ( Hyun Mi Kang ),정병열 ( Byeong Yeal Jung ),문진산 ( Jin San Moon ),임숙경 ( Suk Kyung Lym ),장금찬 ( Geum Chan Jang ),강민수 ( Min Su Kang ),정충일 ( Choong Il Chung ) 한국수의공중보건학회 2009 예방수의학회지 Vol.33 No.1

우유의 품질향상과 유대지불체계 개선

정충일 한국유가공기술과학회 2001 Journal of Dairy Science and Biotechnology (JMSB) Vol.19 No.1

The most important task in Korean dairy industry is to keep the seasonal and annual balance of raw milk supply and demand. Too much surplus milk supply which causes dumping sale of market milk makes dairy industries get in trouble of management, and eventually affects to farmers and consumers economically. As balancing of supply and demand is so important in the free economic market system, the adaption of the quota system of milk production and seasonal price differentiation has been recommended very often as a method of controlling the milk supply and demand. However, this recommendation did not go through successfully due to the strong objection of dairy farmers. Recently, the voice of consumer's requirement for safer and more hygienic, and high protein, low fat level dairy product is getting stronger. By knowledge of this kind changes, quality improvement in nutrients and hygiene is the most positive way to expand the volume of milk consumption. To meet the consumer's demand, therefore, it is necessary to revise the level of milk fat content and the hygienic grading system for the payment system of raw milk.

原乳의 細菌數에 의한 등급제 실시에 따른 乳質改善 효과

鄭忠一,姜國熙 成均館大學校 科學技術硏究所 1993 論文集 Vol.44 No.1

Bulk tank milk of 34 dairy farms in Pochun area, Kyunggido was tested to investigate how much the sanitary quality of raw milk could be improved. The results obtained were summarized as follows : 1. SPC of bulk tank milk of 34 dairy farms was greatly decreased from 85.7% to 18.9% in SPC above 2.1 X 10 exp (5) through an extension service of dairy farming technics and sanitary conditions. 2. The sanitary conditions of cluster and pail of milking machine, a source of bacterial contamination, were also greatly improved. Approximately 80% of the samples showed less than 100/ml in phychrotrophic bacterial count.

原乳의 저장조건에 따른 乳質改善에 관한 硏究

李載英,鄭忠一,裵仁烋 成均館大學校 科學技術硏究所 1984 論文集 Vol.35 No.1

This study was carried out to determine the effects of different storage conditions on bacterial quality of raw milk. During the summer, the ratio of samples which showed total bacterial count below 4.0 x 10 exp(6)/ml were 51.5% in bulk cooled milk and 17.4% in, water cooled milk. The bacterial count of raw milk stored below 5℃ at farms was investigated according to different milk collecting method. 1. The ratio of samples that had total bacterial counts less than 4.0 × 10 exp(6)/ml, as the legal limit was 78.5% in tanklorry, and 43.6%, in ordinary truck transportation system. 2. The ratio of samples that had coliform bacteria below the number of 1.0 x 10 exp(5)/ml was 84.2% in tanklorry, and 58.3% in ordinary truck transportation system. 3. The ratio of samples that had thermoduric bacteria below the number of 1.0 × 10 exp(6)/ml was 80% in tanklorry, and 46.7% in ordinary truck transportation system, 31.1% of latter samples was above 1.0 × 10 exp(5)/ml. 4. The ratio of samples that had psychrotrophic bacteria above the number of 1.0 × 10 exp(6)/ml was 1.5% in case of tanklorry, and 38.3% in ordinary truck transportation system.

市乳의 유통과정에 따른 細菌數의 변화

李載英,裵仁烋,鄭忠一 成均館大學校 科學技術硏究所 1985 論文集 Vol.36 No.1

This study was carried out to investigate the quality changes of market milk taking place throughout their distribution channels. Samples from 5 different plants were collected from delivery centers, stores and milkmen. 1. Samples from 2 plants (B.D) exceeded the legal limit in their total bacteria on the 4th day. And so did others from another 3 plants (A. B. D) on the 5th day. Stores' milk showed the highest rate of consecutive increase in their total bacteria, while milkmen's the next and centers' the lowest. 2. The number of Coliform bacteria exceeded legal limit on the 4th day was found in only one sample (B), while they were not found in others. With the passing of time, they increased in milkmen's on the 5th day, and showed greater increase in stores' thereafter. 3. In all samples except one(B) from stores, psychrotrophio bacteria did not exceed in number, till the 5th day in refrigeration, the level of 10^6-10^7/ml, at which milk begins to gelatinize and change in taste. 4. All the samples but two from stores showed negative reaction in alcohol test till 5th day, and turned positive thereafter. The reactions were similar in boiling test. 5. Till the 7th day, all samples showed the specific gravity vale of 1.028-1.034, within the normal value. Titratable acidifies were within the normal value of 0.18% in all sampler, those from shops being the highest.

SK 목장 원유의 유질 개선 시범연구

강국희,전태욱,정충일 성균관대학교 생명과학자원연구소 1996 生命資源科學硏究 Vol.3 No.1

A case study was conducted on decrease of bacteria and somatic cell count in the raw milk for the raw milk quality improvement. This study was carried on SK dairy farm in Suwon city that had 4 dairy milking cows. The experiment was tested on 2 cows each for control group and treatment group respectively. Criteria of evaluation on raw milk quality were number of total bacteria, Psychrotrophic bacteria, thermophilic bacteria, coli group and somatic cells. All the cows were applied the same feeding system for 86 days (Mar, 14∼Jane, 7) The results obtained were as follows : Milk contents were fat 3.1%∼4.19% for control group and 3.21%∼4.76% for treatment group; protein 2.65%∼4% for control and 3.04%∼4.37% for treatment; carbohydrate 4.09%∼4.86% for control and 4%∼4.94% for treatment. SNF 7.78%∼9.45% for control and 8.05%∼9.7% for treatment. There was no significant difference in milk contents between control group and treatment. The number of total bacteria was about 8.0×10 exp(5)/ml for control group and 1.0 × 10 exp(5)/ml for treatment group. Psychorotophic bacteria were distributed from 1.79 × l0P/ml to 9.55×10 exp(5) /ml for control group and 5.4×10 exp(3)/ml to 8.95×10 exp(5)/ml for treatment group. Thermophilic bacteria indicated from 6.0×10 exp(3)/ml to 8.95×10 exp(5)/ml for control group, and 5.5×10 exp(2)/ml to 1.1×10 exp(4)/ml for treatment group. The coli group indicated about from 1.6×10 exp(3)/ml to 2.3×10 exp(4)/ml for control group and 1.0×10 exp(2)/ml to 2.9×10 exp(4)/ml for treatment group. The number of somatic cells were 1,534,000(±234,012) for cow No. 2; 197,000 (±59,681) for cow No. 4; 4,240,000 (±1,094,459) for cow No. 9; 951,000 (±784,990) for cow No. 13 respectivley during the experiment period. The somatic cell count did not decrease by the sanitary handling on cows and the tools during experiment period.

원유(原乳)의 저온성(低溫性) 세균의 증식에 의한 유질변화(乳質變化)에 관한 연구

이재영,강국희,정충일 한국식품위생안전성학회 1986 한국식품위생안전성학회지 Vol.1 No.2

A trial was carried out to check the seasonal variation in total bacterial counts (T.B.C.) and psychrotrophic bacterial counts (P.B.C.) and to investigate the quality deterioration of raw milk collected from dairy farms in Kyunggi area, Korea. T.B.C. of raw milk exceeded 10^7/ml in summer and 10^6/ml in winter 1980, but they have gradually decreased from 1983. In 1985, the counts showed less than 2 x 10^6/ml through the whole year. The same tendency of improvement in coliform counts was shown. The counts were higher than 10^6/ml in summer and 10^5/ml in winter 1982, but they were kept lower than 1 x 10^5/ml in 1985 through the whole year. Free fatty acids and free amino acids were increased in raw milk stored at 5℃ and 10℃, by the growth of psychrotrophic bacteria.

PCR을 이용한 장구균의 신속 검출 및 가축에서의 장구균 분포

강현미,정병열,문진산,이희수,장금찬,김종만,정충일 한국수의공중보건학회 2001 예방수의학회지 Vol.25 No.4

For the rapid diagnosis of Enterococcus species, we established PCR method with primer, Ent 1 and Ent 2. The 112 bp DNA fragment was amplified among most of enterococci isolates, indicating the specificity of PCR. Prevalence of Enterococcus spp. was investigated from mastitis milk and various livestock. Major enterococci from mastitis milk were E. faecalis (50.5%) and E. faecium (34.5%). Distributions of Enterococcus spp. from livestock samples were E. faecium (42.6%), E. faecalis (17.4%), E. hirae (17.1%), E. casseliflavus (14.4%), E. gallinarum (5.6%), E. durans (2.6%) and E. avium (0.3%). Among enterococci from feces of dairy cow, E. casseliflavus (44.0%) was found to be the most dominant strain following by E. hirae (21.3%). In native cattle (Hanwoo), E. hirae (38.5%) was the dominant strain, following by E. faecium (26.6%), E. faecalis (16.5%), E. durans (7.3%), E. casseliflavus (6.4%), E. gallinarum (3.7%), and E. avium(0.9%). Isolates from porcine showed the distribution of E. faecium(25.0%) and E. casseliflavus (75.0%). In chicken, prevalence of enterococci was E. faecium(68.1%), E. faecalis (27.1%), and E. gallinarum(4.9%).