• 한국미생물·생명공학회지
• /
• 제42권3호
• /
• pp.267-274
• /
• 2014

초고압 공정(HPP)은 비가열 공정 중 하나로 식품 중의 세균 증식을 억제하는 방법으로 근래 들어 산업적으로 각광받고 있다. 현재 우유의 살균은 대부분 가열살균법에 의존하고 있으나, 가열살균은 우유의 영양소 및 이화학적 특성을 변화시키는 단점이 있다. 따라서 본 연구에서는 초고압 처리가 우유의 미생물학적 및 이화학적 특성에 미치는 영향을 알아보았다. 우유를 $15^{\circ}C$에서 600 MPa의 압력조건으로 3분간 처리했을 시 일반세균 및 유산균의 수는 2-3 Log CFU/ml 수준으로 감소하였으며, 대장균군은 HPP 처리 후 $4^{\circ}C$에서 15일 저장 기간 중에 검출되지 않았다. HPP 처리에 따른 유단백의 변성을 알아보고자 유단백의 전기영동 패턴을 분석한 결과, HPP 처리 우유가 가열살균 우유에 비하여 단백질 변성도가 낮게 나타났다. 또한 HPP 처리 우유의 경우 비타민 및 무기질의 함량 변화는 상대적으로 낮았으나, protease, lipase 및 alkaline phsophatase와 같은 우유 효소는 불활성화 시키는 특징을 나타내었다. 이러한 결과는 HPP가 우유의 영양소 파괴 및 이화학적 특성을 변화시키지 않으면서 우유의 미생물 제어에 사용될 수 있음을 제시한다.

• Reproductive and Developmental Biology
• /
• 제39권4호
• /
• pp.97-104
• /
• 2015

Glucose is universal and essential fuel of energy metabolism and in the synthesis pathways of all mammalian cells. Glucose is the one of the major precursors of lactose synthesis using glycolysis result in producing milk fat and protein. During the milk fat synthesis, lipoprotein lipase (LPL) and CD36 are required for glucose uptake. Various morecules such as acyl-CoA synthetase 1 (ACSL1) activity of acetyl-CoA synthetase 2 (ACSS2), ACACA, FASN AGPAT6, GPAM, LPIN1 are closely related with milk fat synthesis. Additionally, glucose plays a major role for synthesizing lactose. Activations of lactose synthesize enzymes such as membranebound enzyme, beta-1,4-galactosyl transferase (B4GALT), glucose-6-phosphate dehydrogenase (G6PD) are changed by concentration of glucose in blood resulting change of amount of lactose production. Glucose transporters are a wide group of membrane proteins that facilitate the transport of glucose over a plasma membrane. There are 2 types of glucose transporters which consisted facilitative glucose transporters (GLUT); and sodium-dependent transport, mediated by the Na+/glucose cotransporters (SGLT). Among them, GLUT1, GLUT8, GLUT12, SGLT1, SGLT2 are main glucose transporters which involved in mammary gland development and milk synthesis. However, more studies are required for revealing clear mechanism and function of other unknown genes and transporters. Therefore, understanding of the mechanisms of glucose usage and its regulation in mammary gland is very essential for enhancing the glucose utilization in the mammary gland and improving dairy productivity and efficiency.

• Journal of Applied Biological Chemistry
• /
• 제61권3호
• /
• pp.245-255
• /
• 2018

본 연구는 Lactobacillus brevis 균주들을 이용하여 제조된 발효콩-분말 두유(fermented soy-power milk, FSPM)의 기능성물질 함량(GABA 및 isoflavone)과 항산화 활성 및 소화효소 저해활성을 비교 측정하였다. 김치로부터 가바 생성 유산균 10종을 분리하였고 16S rRNA 유전 분석 결과 L. brevis와 96-99% 상동성을 나타내었다. GABA 전환율은 MSG, 활성 글루텐과 콩 단백질에서 각각 66.96-93.51%, 63.76-84.58%과 57.05-69.75% 있었다. FSPM은 콩-분말 두유(SPM)보다 pH와 GA 함량은 낮았으나, 산도와 GABA 함량은 높았다. BMK484 균주 FSPM의 GABA 전환율은 69.97%로 가장 우수하였다. 한편, SPM은 배당체 이소플라본의 함량($1290.93{\mu}g/g$)이 높았으나, FSPM는 비당체 이소플라본의 함량($287.27-501.9{\mu}g/g$)이 높았다. BMK484 균주 FSPM의 경우 비당체 이소플라본인 daidzein, glycitein과 genistein 함량이 각각 240.2, 61.24과 $200.45{\mu}g/g$으로 가장 높았다. BMK484 균주 FSPM의 DPPH, ABTS와 hydroxyl 라디칼 소거활성 및 ${\alpha}-glucosidase$와 pancreatic lipase 저해활성은 각 60.31, 88.10와 61.25 및 52.71와 39.37%로 비교적 우수하였다. 따라서 본 연구의 L. brevis들은 발효 콩-분말 두유에서 GABA 및 비당체 이소플라본을 동시에 강화할 수 있는 소재로서 사용될 수 있다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제23권9호
• /
• pp.1184-1189
• /
• 2010

This work was conducted to examine the variation of immunoglobulins (Igs) in serum, immune milk, normal milk and colostrum upon implantation of a new Antigen Releasing Device (ARD). The core of each ARD housed an immunostimulating complex (ISCOM) that was made of adjuvant Quil A and type XIII lipase from a Pseudomonas sp. Each ARD was coated with polylactic acid, known as polylactide, that controls antigen release. Twenty lactating Chinese Holstein cows were divided into 2 groups (n = 10): test group and control group. All cows in the test group were implanted with a single injection in the right iliac lymph node with 3 types of ARDs, which were designed to release the antigens at d 0, 14 and 28 post-implantation. Blood and milk samples were collected from both groups, and colostrum samples were also collected from other post-partum cows in the same farm. Concentrations of $IgG_1$, IgA and IgM in whey and serum were measured by sandwich ELISA. The results showed that the $IgG_1$, IgA and IgM concentrations in serum and whey from the test group were higher than from the control group. Among the three Igs measured, the $IgG_1$ concentration in serum was significantly higher at d 40 after ARD implantation, and the $IgG_1$ concentration in whey peaked at d 9, 17 and 30, which corresponded with release of the antigen. Based on Pearson's correlation between Ig concentration and production parameters, IgA concentration in normal milk was positively correlated with lactation period, which reflected IgA changes during the lactation period in immune milk. In colostrum, $IgG_1$, IgA and IgM decreased abruptly from d 0 to 3, and then decreased slightly. In conclusion, serum $IgG_1$ concentration can be affected by controlled release of the ARD, while whey IgA levels are primarily affected by lactation period. These results may be useful in future studies designed to regulate concentrations of Igs in immune milk.

• 한국식품과학회지
• /
• 제43권6호
• /
• pp.689-695
• /
• 2011

모유대체지를 합성하기 위하여 palm stearin을 acetone fractionation으로 획득한 PPP rich fraction과 oleic ethyl ester를 기질로 사용하고, sn-1,3 위치 선택성을 가진 Lipozyme TLIM을 이용하여 에스테르 교환반응을 수행하였다. 반응 조건(반응 온도, 반응 시간, 기질의 비율)을 요인 변수로 하여 중심 합성 계획에 의한 반응표면분석을 이용하였고, 비 용매 계에서의 반응을 통해 sn-2 위치에 팔미트산의 함량이 높고, sn-1,3에 올레산의 함량이 높은 1,3-dioleoyl-2-palmitoyl glycerol(OPO) 합성 조건을 최적화 하였다. 모델에 의하여 구해진 최적화 조건은 반응온도=$55^{\circ}C$, 반응시간 =3시간, 기질비율=1:6이었고 이때 sn-2 위치의 팔미트산($Y_1$, %)의 함량은 70.70%이었고 sn-1,3 위치의 올레산($Y_2$, %) 함량은 69.58% 이었다. 최적조건에서 합성된 모유대체지를 silver ion HPLC분석 결과 SSS(5.22%), SSU(36.28%), SUU(12.94%), USU(31.24%), UUU(11.04%)로 나타났다. 한편, TAG(90.35 g/100 g), 1,3-DAG (5.66 g/100 g)와 1,2-DAG(4.00 g/100 g)로 구성되어 있었고, 1,3-DAG 가 1,2-DAG 보다 많이 생성되는 것으로 나타났다.

• Journal of Dairy Science and Biotechnology
• /
• 제7권1호
• /
• pp.6-19
• /
• 1989

Twenty-five commercial food grade and alalytical grade lipases were used to study the patterns of release of short-chain free fatty acids (FFA) from milk fat in cheese slurries. Principal component Analysis showed that there were four distinctive groups by the FFA ratios and five groups by the FFA concentrations. However, Average Linkage Cluster Analysis showed that the patterns of FFA released were dependent upon distance defined between groups of lipases. All the lipases tested with both statistical analysis had distinctive specificities in hydrolyzing short-chain FFA from milk fat. Lipases from ruminant-animal origins produced an extremely high ratio (>40%) of butyric acid and a low ratio (<26%) of capric acid to total short chain FFA. Lipases from porcinepancreas and some microbial origins showed balanced production in both bytyric and capric acid. However, most lipases from microbial origins released a high ratio of capric acid but similar ratios to other origin enzymes for short-chain free fatty acids. Ruminant-animal origin lipases produced short-chain FFA much higher in concentration than other lipases. Lipases from porcine pancreas as well as microbial origins showed different concentrations of the fatty acids. Ratios of short-chain FFA in each sample were not significantly changed during incubation periods (4 wk), whereas concentrations of the FFA increased considerably.

• 대한화학회지
• /
• 제60권2호
• /
• pp.118-124
• /
• 2016

파라벤은 화장품, 식품, 의약품 등에 첨가되는 살균성 보존제로 미생물의 성장을 억제한다. 그러나 체내에서 에스트로겐과 유사한 작용을 하는 내분비계 교란물질이며, 특히 독성물질에 민감한 영유아 및 태아에게 노출될 경우 생식기 기형, 고환암, 성조숙증 등 성장발달에 큰 영향을 미친다. 따라서 본 연구에서는 영아가 주로 섭취하는 모유에서의 파라벤 수준을 확인하기 위하여 모유 중 4가지 파라벤(methyl paraben, ethyl paraben, propyl parabne, butyl paraben)의 분석법을 확립하였다. 시료는 액체상추출(Liquid-liquid extraction, LLE)을 통하여 전처리 한 후, 액체크로마토그래피 텐덤 질량분석기(liquid chromatography tandem mass spectrometry, LC-MS/MS)를 사용하여 정량분석 하였다. 확립된 분석조건에서 얻어진 검량선의 직선성은 r² > 0.999이고, 검출한계(LOD)는 0.019~0.044 ng/mL이었다. 또한 정확도는 85.3~105.9%, 정밀도는 10% 이하의 값을 나타내었다. 10개의 모유시료 중 파라벤류의 평균농도 ± 표준편차는 MP 0.660 ± 0.519 ng/mL, EP 1.631 ± 2.081 ng/mL, PP 0.326 ± 0.320 ng/mL이었고, BP는 불검출 되었다.

• 한국미생물·생명공학회지
• /
• 제19권1호
• /
• pp.8-13
• /
• 1991

원유로부터 bacteriocin을 생산하는 미생물을 분리하고 이 균주들을 중심으로 Lactobacillus plantarum을 target organism으로 하여 항균력을 비교하였다. 분리된 항균성물질들은 Gram양성 및 음성균에 대하여 넓은 항균 spectrum을 보였으며 선발균주 중 최종적으로 항균력이 가장 높은 1112-1을 우량균주로 선발하였다. 선발한 1112-2 균주의 항균성물질 230 IU/ml 첨가시에 Lactobacillus plantarum의 생육은 완전히 억제되었으며 500IU/ml 첨가시 E.coli의 생육은 대조구조에 비하여 11 억제되었다.

• 식품과학과 산업
• /
• 제51권2호
• /
• pp.148-156
• /
• 2018

Structured lipids are lipids in which the composition and/or positional distribution of fatty acids have been chemically or enzymatically modified from their natural biosynthetic form. Because structured lipids have desired nutritional, physicochemical, textural or physiological properties for applications in processed foods, functional foods, or nutraceuticals, many research activities have been aimed at their commercialization. The enzymatic production of structured lipids using lipases as the biocatalysts has a big potential in the future market due to the specificity or selectivity of the lipases. This article introduced some examples of specialty structured lipids that have been enzymatically produced and have been utilized as commercialized products. The commercialized products include medium- and long-chain triacylglycerols, human milk fat substitutes, cocoa butter equivalents, trans-free plastic fats, low-calorie fats/oils, and health-beneficial fatty acid-rich oils.

• Asian-Australasian Journal of Animal Sciences
• /
• 제33권6호
• /
• pp.1012-1022
• /
• 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.