• 한국식품과학회지
• /
• 제38권1호
• /
• pp.42-46
• /
• 2006

우유단백질과 검류의 혼합 첨가가 빵의 노화를 억제시키는데 사용될 수 있는지를 조사하기 위하여 이들 첨가한 밀가루의 amylogram, farinogram 그리고 extensogram을 측정하였다. 또한 우유단백질과 검류를 첨가한 반죽을 8주 동안 냉동 저장한 후 이 냉동반죽으로 식빵을 제조하고, 만든 당일과 $5^{\circ}C$에서 4일간 저장한 식빵의 수분함량 변화와 경도 변화를 측정하여 노화정도를 비교하였다. Amylogram 특성 중 우유단백질과 검류를 첨가한 밀가루의 호화 개시온도가 증가하였고 CA와 WA 첨가한 밀가루의 최고 점도가 대조구보다 낮았다. Farinogram 특성을 통해 우유단백질과 검류가 밀가루의 수분 흡수율을 증가시키는 것과 CA와 WA를 첨가할 경우 반죽 형성시간이 길어짐을 확인할 수 있었다. Extensogram 특성에서 밀가루의 신장도는 우유단백질과 검류를 첨가함으로써 낮아지는 현상을 보였다. 빵의 수분함량 변화를 살펴보면, 4일 저장기간 동안 모든 빵의 수분이 감소되는 것을 알 수 있었으며, 냉동저장 6주후부터는 대조구 빵의 수분함량이 우유단백질과 검류를 첨가한 빵보다 감소정도가 큰 것을 확인할 수 있었다. 빵의 경도 변화의 경우 또한 저장기간 동안 대조구 빵이 우유단백질과 검류를 첨가한 빵, 특히 CA와 WA를 첨가한 빵보다 높은 경도를 나타냈다. 이를 통해서 우유단백질과 검류를 첨가할 경우 반죽의 제빵 적성을 향상시켜주며 CA와 WA의 첨가는 빵의 노화를 지연시켜주는데 효과가 있는 것으로 생각된다.

• 한국식품과학회지
• /
• 제32권3호
• /
• pp.564-569
• /
• 2000

가공식품중의 우유단백질 분석을 위하여 효소면역측정법, ELISA를 개발하였다. 특이 항체를 생산하기 위해 열에 안정하고 우유의 주요한 단백질인 ${\alpha}_{s1}-CN$을 토끼에 면역하였다. 항${\alpha}_{s1}-CN$ 항체를 이용하여 간접경합 ELISA를 실시한 결과 검출한계는 $0.1\;{\mu}g/mL$ 이었고 ${\alpha}_{s1}-CN$, skim milk, ${\beta}-CN$과 whey protein isolate에 대한 특이항체의 반응성은 각각 100%, 37%, 0.14%과 0.04% 이었다. 그러나 다른 우유단백질인, ${\beta}-lactoglobulin,\;{\alpha}-lactalbumin$, bovine serum albumin 과 대두단백질인 isolated soy protein 에 대해서는 거의 반응성을 보이지 않았다. 샌드위치 ELISA 결과는 검출한계가 $0.01\;{\mu}g/mL$로 간접경합 ELISA 에 비하여 10배 정도 민감해져 따라서 이를 시료 분석에 이용하였다. 시유에 1-10%의 whole CN을 첨가한 spike test 결과 whole CN의 평균 회수율이 94.8%(CV, 8.2%)으로 나타났다. 식품재료와 유가공 제품에 대한 whole CN의 정량분석을 실시한 결과 탈지유는 29%, WPI는 0.03%, 농후 요구르트는 0.25%였으며 가공치즈는 6.9%로 나타났다.

• 한국축산식품학회지
• /
• 제29권5호
• /
• pp.633-639
• /
• 2009

본 연구는 유단백질에 단백질 분해효소를 처리하여 가수분해 후 저분자 peptide를 ABTS법을 이용하여 항산화 활성을 측정하여 유단백질 유래 저분자 peptide의 항산화력을 측정하고자 하였다. Chymotrypsin 처리한 유청단백질의 가수분해도가 가장 높았으며, 유청단백질의 락트알부민 및 락토글로브린이 분해되어 분자량 20 kDa 이하의 저분자 단백질이 생성된 것을 전기영동을 통하여 확인하였다. 유단백질의 농도에 따른 항산화 활성을 측정한 결과, 카제인의 항산화 활성이 유청단백질보다 높게 나타났다. 유단백질을 효소에 의하여 가수분해 시 항산화 활성이 증가하였으며, 카제인 가수분해물이 유청단백질 가수분해물과 비교하여 항산화 활성이 더 높았으나, 가수분해도와 항산화 활성도의 관계는 일치하지 않았다. Trypsin에 의한 카제인 가수분해 물의 항산화 활성이 80.7%로 가장 높았다. 본 연구에서는 chymotrypsin과 trypsin에 의한 분자량 3 kDa의 카제인 분획물의 항산화 활성이 가장 우수 하였으며, 유청단백질을 trypsin으로 분해하였을 때 항산화 활성이 증가하였다.

• Reproductive and Developmental Biology
• /
• 제40권1호
• /
• pp.7-13
• /
• 2016

Effectiveness of transgene transfer into genome is crucially concerned in mass production of the bio-pharmaceuticals using genetically modified transgenic animals as a bioreactor. Recently, the mammary gland has been considered as a potential bioreactor for the mass production of the bio-pharmaceuticals, which appears to be capable of appropriate post-translational modifications of recombinant proteins. The mammary gland tissue specific vector system may be helpful in solving serious physiological disturbance problems which have been a major obstacle in successful production of transgenic animals. In this study, to minimize physiological disturbance caused by constitutive over-expression of the exogenous gene, we constructed new retrovirus vector system designed for mammary gland-specific expression of the hEPO gene. Using piggyBac vector system, we designed to express hEPO gene under the control of mammary gland tissue specific and lactogenic hormonal inducible goat ${\beta}$-casein or mouse Whey Acidic Protein (mWAP) promoter. Inducible expression of the hEPO gene was confirmed using RT-PCR and ELISA in the mouse mammary gland cells treated with lactogenic hormone. We expect the vector system may optimize production efficiency of transgenic animal and reduce the risk of global expression of transgene.

• Journal of Dairy Science and Biotechnology
• /
• 제19권1호
• /
• pp.13-21
• /
• 2001

Milk can be regarded as a complete food, containing protein, fat, lactose, vitamins and minerals. Milk is heated for a variety of reasons. The main reasons are: to remove pathogenic organisms; to increase shelf-life. But, when milk is heated, many changes take place: denaturation of whey proteins and interaction with casein, Maillard browning, losses of vitamin and minerals. The addition of a additive and milk powder to flavor and taste may cause undesirable change of quality during heating milk. The reconstituted milk is the milk product resulting from the addition of water to the dried or condensed form in the amount necessary to re-establish the specified water solids ratio. Therefore, according to the increasement of consumption of processed milk, the necessity for study about the quality of processed milk mixed with reconstituted milk arose.

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

• 한국축산식품학회지
• /
• 제40권5호
• /
• pp.689-698
• /
• 2020

The aim of study was to scrutinize the physicochemical and protein profile of milk obtained from local Pakistani breeds of milch animals such as Nilli-Ravi buffalo, Sahiwal cow, Kajli sheep, Beetal goat and Brela camel. Physicochemical analysis unveiled maximum number of total solids and protein found in sheep and minimum in camel. Buffalo milk contains the highest level of fat (7.45%) while camel milk contains minimum (1.94%). Ash was found maximum in buffalo (0.81%) and sheep (0.80%) while minimum in cow's milk (0.71%). Casein and whey proteins were separated by subjecting milk to isoelectric pH and then analyzed through sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The results showed heterogeneity among these species. Different fractions including α_S1, α_S2, κ-casein, β-casein and β-lactoglobulen (β-Lg) were identified and quantitatively compared in all milk samples. Additionally, this electrophoretic method after examining the number and strength of different protein bands (α_S1, α_S2, β-CN, α-LAC, BSA, and β-Lg, etc.), was helpful to understand the properties of milk for different processing purposes and could be successfully applied in dairy industry. Results revealed that camel milk was best suitable for producing allergen free milk protein products. Furthermore, based on the variability of milk proteins, it is suggested to clarify the phylogenetic relationships between different cattle breeds and to gather the necessary data to preserve the genetic fund and biodiversity of the local breeds. Thus, the study of milk protein from different breed and species has a wide range of scope in producing diverse protein based dairy products like cheese.

• Journal of Dairy Science and Biotechnology
• /
• 제16권2호
• /
• pp.98-105
• /
• 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 result suggested that peptides from various milk products could be utilized as a good bioactive agents for developing health functional foods.

• 한국유가공학회:학술대회논문집
• /
• 한국유가공기술과학회 1998년도 제46회 춘계 유가공 심포지움 - 우유 및 유제품의 기능성
• /
• pp.22-29
• /
• 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.

• 한국식품과학회지
• /
• 제18권5호
• /
• pp.357-363
• /
• 1986

식품의 주요 구성 성분의 현탁액에 대한 열전도도와 열확산도를 $-40^{\circ}C\;-150^{\circ}C$의 온도 범위와 10%-60%의 농도 범위애서 측정하였다. 세 종류의 서로 다른 농도에서 측정된 실험값으로부터 가정된 모델에 의해 순수 성분의 열전도도와 열확산도를 각각의 온도에서 구한 다음 컴퓨터 프로그램을 이용하여 모델의 상수들을 구하였다. 본 연구에서 발전시킨 모델을 사용하여 얻은 식품의 열전도도와 열확산도 수치를 기발표된 모든 액체식품의 데이타와 비교해 본 결과 3.8%의 오차가 있었다. 식품의 주요 구성 성분의 함량과 온도가 주어지면 본 연구에서 발전시킨 모델을 이용하여 열전도도와 열확산도 수치를 위의 오차 한계에서 구할 수 있다.