• 한국축산식품학회지
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• 제30권6호
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• pp.923-929
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• 2010

Colostral whey prepared from colostrum (pooled from first six post-partum milkings) was heated for 10 min at $100^{\circ}C$ Heated colostral whey was incubated with 1% enzymes (protein equivalent basis) for 15, 30, 60, 90, and 120 min at $50^{\circ}C$. Papain, pepsin, trypsin, and alcalase produced different degrees of hydrolysis (DH), 10.66%, 12.42%, 10.83%, and 25.31%, respectively, at an incubation time of 120 min. The SDS-PAGE reveals that significant amounts of bovine serum albumin (BSA), ${\beta}$-lactoglobulin (${\beta}$-LG), and ${\alpha}$-lactalbumin (${\alpha}$-LA) survived papain digestion. In contrast, pepsin completely removed BSA but not ${\beta}$-LG present in heated colostral whey. Alcalase completely eliminated BSA, ${\beta}$-LG, and ${\alpha}$-LA. This differential hydrolysis was confirmed by reversed-phase HPLC analysis. Using ion-exchange chromatography, fraction-1 (F-1) was obtained from alcalase hydrolysate at a NaCl gradient concentration of 0.25 M. Reversed-phase HPLC chromatograms of alcalase F-1 showed numerous small peaks, which probably indicate that a variety of new peptides were produced. Iron content of alcalase F-1 was 28.94 ppm, which was the highest among all enzyme fractions, whereas iron content of colostral whey was 36.56 ppm. Main amino acids contained in alcalase F-1 were Thr (15.45%), Glu (14.12%), and Ser (10.39%). Therefore, alcalase can be used to generate good iron-binding peptides in heated colostral whey, and the resulting iron-binding peptides could be suitable as a value-added food ingredient for food supplements.

• 한국축산식품학회지
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• 제37권1호
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• pp.62-70
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• 2017

The aim of this study was identifying a suitable food grade enzymes to hydrolyze whey protein concentrates (WPCs), to give the highest bioactivity. WPCs from ultrafiltration retentate were adjusted to 35% protein (WPC-35) and hydrolyzed by enzymes, alcalase, ${\alpha}-chymotrypsin$, pepsin, protease M, protease S, and trypsin at different hydrolysis times (0, 0.5, 1, 2, 3, 4, and 5 h). These 36 types of hydrolysates were analyzed for their prominent peptides ${\beta}-lactoglobulin$ (${\beta}-Lg$) and ${\alpha}-lactalbumin$ (${\alpha}-La$), to identify the proteolytic activity of each enzyme. Protease S showed the highest proteolytic activity and angiotensin converting enzyme inhibitory activity of IC50, 0.099 mg/mL (91.55%) while trypsin showed the weakest effect. Antihypertensive and antioxidative peptides associated with ${\beta}-Lg$ hydrolysates were identified in WPC-35 hydrolysates (WPH-35) that hydrolyzed by the enzymes, trypsin and protease S. WPH-35 treated with protease S in 0.5 h, responded positively to usage as a bioactive component in different applications of pharmaceutical or related industries.

• 농업과학연구
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• 제47권3호
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• pp.459-470
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• 2020

This study investigated the effects of the proteolytic hydrolysates of α-lactalbumin (LA), β-lactoglobulin (LG) and bovine serum albumin (BSA) by alcalase on inflammatory cytokines. The proteolytic hydrolysates were separated into two fraction of peptides, ≤ 10,000 Da and > 10,000 Da, respectively, because various low molecular weight peptides were generated during the hydrolysis reaction time. Among the hydrolysate peptides, BSA (all types), β-LG (> 10,000 Da), and α-LA (> 10,000 Da) showed an inhibitory activity against thymic stromal lymphopoietin (TSLP) mRNA expression in lipopolysaccharide-induced RAW264.7 murine macrophages. α-LA (> 10,000 Da), β-LG (hydrolysates), and BSA (> 10,000 Da) showed an inhibitory activity against tumor necrosis factor (TNF)-α expression. α-LA (all types), β-LG (hydrolysates, > 10,000 Da), and BSA (> 10,000 Da) showed an inhibitory activity against interleukin-6 (IL-6) expression. α-LA (> 10,000 Da), β-LG (> 10,000 Da), and BSA (all types) showed an inhibitory activity against inducible nitric oxide synthase (iNOS) expression. α-LA (> 10,000 Da), β-LG (> 10,000 Da), and BSA (all types) showed an inhibitory activity against cyclooxygenase (COX)-2 expression. The lowest level of TNF-α production was measured with α-LA (> 10,000 Da) and β-LG (> 10,000 Da) for all types, and a similar low level was measured for all types of BSA. The highest level of IL- 6 production was measured with α-LA (≤ 10,000 Da) among α-LA, β-LG, and IL-6. The low level of NO production was similar with α-LA, β-LG, and BSA but not with α-LA (≤ 10,000 Da). These potential peptides from whey protein hydrolysates could be used for food, medicinal, and industrial applications.

• Journal of Dairy Science and Biotechnology
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• 제30권1호
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• pp.17-22
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• 2012

Since the prevalence of allergies is increasing, food allergy is a major concern for consumers, as well as for the food industry. The foods that account for over 90% of all moderate to severe allergic reactions to food are milk, eggs, peanuts, soybeans, fish, shellfish, wheat, and tree nuts. Of these food allergens, milk is one of the major animal food allergens in infants and young children. Milk is the first food that an infant is exposed to; therefore, the sensitization rate of milk in sensitive individuals is understandably higher. The mechanisms involved in allergic reactions caused by this hypersensitivity are similar to those of other immune-mediated allergic reactions. The reactions occur in the gastrointestinal tract, skin, and respiratory tract, with headaches and psychological disorders occurring in some instances. The major allergenic proteins in milk are casein, ${\beta}$-lactoglobulin, and ${\alpha}$-lactalbumin, while some of the minor allergenic proteins are lactoferrin, bovine serum albumin, and immunoglobulin. Reliable allergen detection and quantification are essential for compliance with food allergen-labeling regulations, which protect the consumer and facilitate international trade.

• Mass Spectrometry Letters
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• 제5권3호
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• pp.63-69
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• 2014

In this study, we present a new isotope-coded carbamidomethylation (iCCM)-based quantitative proteomics, as a complementary strategy for conventional isotope labeling strategies, with providing the simplicity, ease of use, and robustness. In iCCM-based quantification, two proteome samples can be separately isotope-labeled by means of covalently reaction of all cysteinyl residues in proteins with iodoacetamide (IAA) and its isotope (IAA-$^{13}C_2$, $D_2$), denoted as CM and iCCM, respectively, leading to a mass shift of all cysteinyl residues to be + 4 Da. To evaluate iCCM-based isotope labeling in proteomic quantification, 6 protein standards (i.e., bovine serum albumin, serotransferrin, lysozyme, beta-lactoglobulin, beta-galactosidase, and alpha-lactalbumin) isotopically labeled with IAA and its isotope, mixed equally, and followed by proteolytic digestion. The resulting CM-/iCCM-labeled peptide mixtures were analyzed using a nLC-ESI-FT orbitrap-MS/MS. From our experimental results, we found that the efficiency of iCCM-based quantification is more superior to that of mTRAQ, as a conventional nonisobaric labeling method, in which both of a number of identified peptides from 6 protein standards and the less quantitative variations in the relative abundance ratios of heavy-/light-labeled corresponding peptide pairs. Finally, we applied the developed iCCM-based quantitative method to lung cancer serum proteome in order to evaluate the potential in biomarker discovery study.

• Journal of Dairy Science and Biotechnology
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• 제16권2호
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• pp.106-118
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• 1998

유청은 치즈제조시 부산물로 얻어지는 천연물이며, 새로운 기술발전에 따라 유청단백질의 농축물과 유청분획물들이 여러모로 이용 가능하게 되었고, 또한 여러 종류의 식품의 원료로 제공하게 되었다. 농축 유청단백질은 겔화, 유화성, 휩핑, 수분결합성, 지방대체성 등의 다양한 기능성을 함유하고 있다. 유청의 새로운 분획물인 알파락트알부민, 락토페린, 락토페록시다아제, 펩타이드 등은 이들의 생활성이나 건강향상성때문에 전세계적으로 관심이 높다. 이들 분획물에서 천연 항생물질, 천연 보존료 및 면역 향상 물질 등으로 새롭게 사용이 가능한 것으로 발견되었다. 기능성 식품산업의 성장에 힘입어 증가 추세에 있는 많은 제조업자들이 새로운 제품개발을 성공적으로 하는데 유청의 영양적, 기능적 조건들이 유리하다. 미국은 유청생산이 전세계에서 가장 큰 유일한 생산국이고 또한 수출국이다. 1997년에는 백만톤 이상의 유청제품들이 미국에서 제조되었다.

• 한국식생활문화학회지
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• 제22권1호
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• pp.97-103
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• 2007

In this study, physicochemical properties and the antioxidative activity of whey protein isolate(WPI) for com germ oil were measured. The pH of WPI was 6.26, and the titrable acidity was 0.18%. The WPI’s moisture content was 5.2% and each of the other element content such as lactose, crude protein, crude ash and crude fat was found to be 0.8%, 90.7%, 2.7% and 0.6%, respectively. The amounts of active SH group in WPI 9 ${\mu}$ M-g and total colony counts of bacteria was 5.9 ${\times}$ 10$^3$ CFU-g. ${\alpha}$-Lactalbumin, ${\beta}$-lactoglobulin and bovine serum albumin(BSA) were shown in WPI as major protein by electrophoresis. The antioxidative effect of WPI and other antioxidants on com germ oil used as substrate was determined by peroxide value(POV) and conjuqated dienoic acid value(CDV). By these results, the order of antioxidative effects could be defined as BHT 0.02%>ascorbic acid 0.1%>WPI 0.1%>WPI 0.02%>ascorbic acid 0.02%>control>tocopherol 0.02%>tocopherol 0.1%, respectively. Also the induction period of com germ oil added with WPI was longer by 1.6 times than that of control(none added any antioxidant). Therefore the fact suggested that WPI could be utilized as a good antioxidative agents.

• 한국식품영양과학회지
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• 제22권2호
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• pp.208-214
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• 1993

인삼 유청음료를 렌넷유청, 인삼, 감미료, 꿀, 매실 등에 종류가 다른 유산균주들을 접종하여 제조한 후, 일부는 발효시키고 일부는 비발효 상태로 4$^{\circ}C$ 및 30$\pm$1$^{\circ}C$에 저장하여 이화학적 및 미생물학적 특성들을 조사하였다. 유청의 수율은 78.8%였고 저장기간 동안 pH는 감소하였으며 적정산도는 증가하였다. 인삼 유청음료의 고형성분, 회분, 지방질 함량은 각각 7.90~8.20%, 0.62~0.66%, 0.16%이었고 단백질 함량은 0.42~0.56%였으며 저장기간에 따라서 큰 변화가 없었다. 유당함량은 유산균 발효시킨 시료가 발효시키지 않은 시료보다 높았다. D(-)- 및 L(+)- 젖산함략은 저장 기간(1~5주)중에 유산균 발효 인삼 유청 음료(17.3~156.1 mg/100g, 347.3~1894.2mg/100g)는 비발효 인삼 유청음료(6.2~82.8mg/100g, 7.1~885.5mg/100g)보다 높았다. 유산균으로 발효시키지 않은 시료와 Lac. casei sub-sp. casei와 Str. salivarius sub-sp. thermophilus를 접종하여 발효시킨 시료의 총 saponin 함량은 저장기간이 경과함에 따라 증가하는 추세였으나 Lac. acidophilus와 Lac. delbrueckii sub-sp. bulgaricus를 접종한 시료는 감소하는 경향을 나타냈다. 인삼 유청음료의 전기영동 결과 모든 시료에서 $\alpha$-la과 $\beta$-lg이 뚜렷이 나타났으며 저장기간에 따라 변화가 거의 없었다. 저장기간(제 1, 3주)동안 대장균군은 검출되지 않았으며 총세균수와 저온성 세균군은 저장기간이 경과함에 따라 증가하였다.

• Journal of Dairy Science and Biotechnology
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• 제25권1호
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• pp.15-20
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• 2007

본 연구는 항원성을 저감한 유제품 개발을 위한 기초자료 도출을 위해 감마선 조사 처리시 퀘소블랑코 치즈의 화학적, 미생물학적 및 항원성 변화를 비교하였다. 퀘소블랑코 치즈는 제조과정에서 85$^{\circ}$C 열처리와 산에 의해 커드를 형성시켜 제조하는 신선치즈로 스타터 유산균을 첨가하지 않지만, 제조 시에 7.65${\pm}$0.04 log CFU/g의 총세균과 7.64${\pm}$0.02 log CFU/g의 유산균수를 나타내었다. 이는 원유 내 미생물중 85$^{\circ}$C에 사멸하지 않은 내열성 유산균이 압착 및 건조 과정에서 생장한 때문으로 생각된다. 대장균군은 검출되지 않았으나, 원유 내에 열과 산에 강한 유해균의 존재시 압착 및 건조 과정에서 증식할 가능성이 높다. 감마선 조사처리시에는 IkGy에서 5.45${\pm}$0.02 log CFU/g, 2kGy에서 2.12${\pm}$0.12 log CFU/g의 유산균수를 나타내었으나, 3kGy 이상에서는 전혀 검출되지 않아 안전성 확보가 가능한 것으로 나타났다. 한편, 감마선 조사에 의한 항원성 저감은 관찰되지 않았는 바 이는 치즈 제조과정에서 상당한 열처리가 이루어지고, 유단백질에서 주요한 항원성을 나타내는 ${\beta}$-lactoglobulin이나 ${\alpha}$-lactalbumin등 유청단백질이 대부분 치즈 제조과정에서 제거되었기 때문으로 생각된다.

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