• 한국축산식품학회지
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• 제40권1호
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• pp.87-95
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• 2020

In this study, we separated and purified lipase inhibitory peptide from fermented milk by Lactobacillus plantarum Q180 with the aim of developing a new functional anti-lipase activity yogurt product. L. plantarum 180 was inoculated into 10% reconstituted skimmed milk and incubated at 37℃ until the pH of the culture reached pH 4.4. The lipase activity was measured using porcine pancreatic lipase. The lipase inhibitory peptides were gradually isolated by ultrafiltration, reversed phase column chromatography (RPC), reversed phase high-performance liquid chromatography (RP-HPLC), and gel permeation high-performance liquid chromatography (GP-HPLC) from the fermented milk by L. plantarum Q180. An ODS-AQ column was used for the RPC, a Vydac C18 column for the RP-HPLC, and a Superdex Peptide HR column for the GP-HPLC. The peptide was composed of Asp, Thr, Ile, Ser, Ala, and Gln, and the anti-lipase activity (IC₅₀) was 2,817 ㎍/mL.

• 한국축산식품학회지
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• 제42권1호
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• pp.46-60
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• 2022

In this study, angiotensin-I-converting enzyme inhibitory (ACEI) activity was evaluated in fermented goat milk fermented by lactic acid bacteria (LAB) from fermented foods and breast milk. Furthermore, the potential for ACEI peptides was identified in fermented goat milk with the highest ACEI activity. The proteolytic specificity of LAB was also evaluated. The 2% isolate was inoculated into reconstituted goat milk (11%, w/v), then incubated at 37℃ until pH 4.6 was reached. The supernatant produced by centrifugation was analyzed for ACEI activity and total peptide. Viable cell counts of LAB and titratable acidity were also evaluated after fermentation. Peptide identification was carried out using nano liquid chromatography mass spectrometry (LC-MS/MS), and potential as an ACEI peptide was carried out based on a literature review. The result revealed that ACEI activity was produced in all samples (20.44%-60.33%). Fermented goat milk of Lc. lactis ssp. lactis BD17 produced the highest ACEI activity (60.33%; IC₅₀ 0.297±0.10 mg/mL) after 48 h incubation, viable cell counts >8 Log CFU/mL, and peptide content of 4.037±0.27/mL. A total of 261 peptides were released, predominantly derived from casein (93%). The proteolytic specificity of Lc. lactis ssp. lactis BD17 through cleavage on the amino acid tyrosine, leucine, glutamic acid, and proline. A total of 21 peptides were identified as ACEI peptides. This study showed that one of the isolates from fermented food, namely Lc. lactis ssp. lactis BD17, has the potential as a starter culture for the production of fermented goat milk which has functional properties as a source of antihypertensive peptides.

• 한국유가공학회:학술대회논문집
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• 한국유가공기술과힉회 2008년도 추계학술대회 논문집
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• pp.39-50
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• 2008

The immune system of mammals includes a complex array of cells and molecules, which interact to provide protection from pathogenic microorganisms. The beneficial role played by lactic acid bacteria and milk-derived peptide in the humans, including the effects on the immune system, has been extensively reported. They are present in dairy products and are frequently used as nutraceuticals to some improve some biological functions in the host. The activation of the systemic and secretory immune response by lactic acid bacteria and milk-derived peptide requires many complex interactions among th different constituents of the intestinal ecosystem. The aim of this review was to make the point about the immunological potential of lactic acid bacteria and milk-derived peptide.

• 한국축산식품학회지
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• 제37권3호
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• pp.402-409
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• 2017

A novel peptide having free radical scavenging activity was separated, using an on-line high-performance liquid chromatography (HPLC) - ABTS screening method, from bovine skim milk fermented by Lactococcus lactis SL6 (KCTC 11865BP). It was further purified using reverse phase-HPLC (RP-HPLC) and sequenced by RP-HPLC-tandem mass spectrometry. The amino acid sequence of the identified peptide was determined to be Phe-Ser-Asp-Ile-Pro-Asn-Pro-Ile-Gly-Ser-Glu-Asn-Ser-Glu-Lys-Thr-Thr-Met-Pro-Leu-Trp (2,362 Da), which is corresponding to the C-terminal fragment of bovine ${\alpha}_{s1}$-casein (f179-199). The hydroxyl radicals scavenging activity ($IC_{50}$ $28.25{\pm}0.96{\mu}M$) of the peptide chemically synthesized based on the MS/MS data showed a slightly lower than that of the natural antioxidant Trolox ($IC_{50}$ $15.37{\pm}0.52{\mu}M$). Furthermore, derivatives of the antioxidant peptide were synthesized. The antioxidative activity of the derivatives whose all three proline residues replaced by alanine significantly decreased, whereas replacement of two proline residues in N-terminal region did not affect its antioxidative activity, indicating that $3^{rd}$ proline in C-terminal region is critical for the antioxidative activity of the peptide identified in this study. In addition, N-terminal region of the antioxidant peptide did not show its activity, whereas C-terminal region maintained antioxidative activity, suggesting that C-terminal region of the peptide is important for antioxidative activity.

• 식품과학과 산업
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• 제51권4호
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• pp.302-312
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• 2018

우유 단백질과 같은 식이 단백질은 분해되기 전에는 대사 조절을 위한 생물학적인 활성을 나타내지 않으나 장에서의 소화과정이나 단백질 분해 효소, 또는 미생물 발효 과정을 통하여 저분자의 펩타이드로 분해되어 수용체 결합을 통하여 생체조절기능을 발휘하거나, 체내 대사의 조절에 관여하는 다양한 효소의 활성을 억제함으로써 기능을 발휘하기도 한다. 우유단백질의 섭취에 의한 혈당 감소 효과는 여러 연구자에 의하여 확인되었으며, 그 작용 기전은 주로 분지사슬 아미노산에 의한 인슐린 분비촉진 기전과 음식물의 소화 과정 중 위장관에서 췌장에서 인슐린 분비 촉진, glucagon의 분비를 감소시켜 혈당을 감소시키는 역할을 담당하는 내분비 호르몬의 일종인 GLP-1의 작용에 영향을 미치는 기전을 생각할 수 있다. 생리적 환경에서 GLP-1은 GLP-1을 가수분해하여 불활성화시키는 DPP-4에 의하여 빠르게 분해되어 생물학적 활성을 소실하기 때문에 DPP-4 억제제는 제 2형 당뇨의 새로운 치료 방법으로써 주목을 받고 있다. DPP-4의 억제 효능을 가진 다수의 기능성 펩타이드가 우유단백질의 분해에 의하여 생성됨이 보고되었으며 그 효능이 in vitro 연구는 물론 동물 모델을 이용한 연구에서도 증명되었다. 이상의 연구 결과를 근거로 할 때 우유 단백질 유래 DPP-4 억제 펩타이드는 인체 적용 연구를 통하여 혈당 조절에 도움을 주는 기능성 소재로 개발될 수 있는 충분한 가능성을 가지고 있다고 판단된다.

• 한국식품과학회지
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• 제18권6호
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• pp.492-496
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• 1986

환원탈지유배지에서 자란 Lactobacillus helveticus YM-1의 cell-free filtrate로부터 Streptococcus thermophilus CH-1의 생육촉진을 확인한 결과 이 물질은 분자량이 5,000정도의 peptide로 나타난다. 이 peptide 중에는 aspartic acid, Iysine, proline, leucine, valine, alanine, glutamic acid등의 amino산이 비교적 풍부하였으며, 그중에서 glutamic acid 함량이 가장 높았다. 또 이 Peptide가 생육 촉진효과 나타내는데 가장 중요한 역할을 담당하는 것은 glutamic acid와 Phenylalanine으로 판단되었다.

• 한국축산식품학회지
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• 제35권3호
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• pp.360-369
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• 2015

Milk proteins have many potential sequences within their primary structure, each with a specific biological activity. In this study, we compared and investigated the bioactivities of hydrolysates of the domestic (A, B) and imported (C, D) skim milk powders generated using papain digestion. MALDI-TOF analysis revealed that all milk powder proteins were intact, indicating no autolysis. Electrophoretic analysis of hydrolysates showed papain treatment caused degradation of milk proteins into peptides of various size. The antioxidant activity of the hydrolysates, determined using 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and total phenolic contents (TPC) assays, increased with incubation times. In all skim milk powders, the antioxidant activities of hydrolysates were highest following 24 h papain treatment (TPC: A, 196.48 μM GE/L; B, 194.52 μM GE/L; C, 194.76 μM GE/L; D, 163.75 μM GE/L; ABTS: A, 75%; B, 72%; C, 72%; D, 57%). The number of peptide derived from skim milk powders, as determined by LC-MS/MS, was 308 for A, 283 for B, 208 for C, and 135 for D. Hydrolysate A had the highest antioxidant activity and the most potential antioxidant peptides amongst the four skim milk powder hydrolysates. A total of 4 β-lactoglobulin, 4 α_s1-casein, and 56 β-casein peptide fragments were identified as potential antioxidant peptides in hydrolysate A by LC-MS/MS. These results suggest that domestic skim milk could have applications in various industries, i.e., in the development of functional foods.

• 한국축산식품학회지
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• 제29권5호
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• pp.633-639
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• 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.

• Journal of Dairy Science and Biotechnology
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• 제17권1호
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• pp.50-57
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• 1999

Milk is a first food for as long as the mammalian race has existed. A characteristic unique to mammal is their ability to secrete milk as a source of nutrients and immunological protection for their young. From a nutitrional viewpoint, milk has heen described as nature's most perfect food, owing mainly to its biological role as the only source of nutrition for the infant mammal. Milk is estimated to contain more than 100,000 molecular species, However, the average contents of milk can be simplified to 3.4% fat, 3.1% protein (80% casein protein and 20% whey protein), 4.5% lactose, and 0.7% ash. Chemically, milk is a very complex fluid rich in nutrients, antibodies, growth factors, antimicrobial components etc. This report will discuss functional properties of milk components, such as lactoferrin, opoid peptide, CPP, cGMP and sialic acid etc.

• 한국유가공학회:학술대회논문집
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• 한국유가공기술과힉회 2007년도 추계학술발표대회
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• pp.39-47
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• 2007

골은 지속적으로 재형성이 일어나며, 오래된 골을 흡수하는 파골세포와 새로운 골을 생성하는 조골세포의 균형에 의하여 항상성이 유지된다. 골대사의 건전성을 측정하기 위한 골흡수 표시자에는 tartrate resistant acid phosphatase, pyridinium 연결부위, 콜라겐 telopeptide 등이 있으며, 골 형성 표시자로는 골 유래 alkaline phosphatase, osteocalcin, procollagen I extension peptide를 사용할 수 있다. 골밀도를 증진하기 위한 기능성 소재로는 milk basic protein, lactoferrin 등이 있으며, 우유의 유산균 발효과정에 의하여 생산되는 생리활성 펩타이드도 골밀도의 증진에 기여할 수 있다. Lactobacillus casei ATCC 393을 이용하여 생산한 발효분해물은 다양한 조골세포의 생화학적 지표 평가와 동물실험 결과를 근거로 할 때 조골세포의 증식과 분화를 촉진하고 파골세포의 활성을 억제시킴으로써 골대사를 개선할 수 있는 것으로 나타났다.