• 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.

• Animal Bioscience
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• 제34권1호
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• pp.2-11
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• 2021

Objective: The aim of the study was to evaluate the influence of polymorphic loci and other factors on milk performance and the technological properties of milk. Methods: The analysis was performed on Simmental and Holstein cows in field conditions (n = 748). Milk yield in kg, fat and protein percentage and yield were evaluated. Technological properties were evaluated by milk fermentation ability, renneting, and an alcohol test. Polymorphisms in the acyl-CoA diacylgycerol transferase 1 (DGAT1), leptin (LEP), fatty acid synthase (FASN), stearoyl CoA desaturase 1 (SCD1), casein beta (CSN2), casein kappa (CSN3), and lactoglobulin beta genes were genotyped, and association analysis was performed. Results: The DGAT1 AA genotype was associated with higher milk, protein and fat yields (p<0.05). The MM genotype in the LEP gene was associated with a lower protein percentage and the W allele with a higher protein percentage (p<0.05). In cows with the FASN GG genotype, the protein percentage was higher, but the A allele was associated with higher milk, protein and fat yields than the G allele. The TT genotype in SCD1 was associated with the lowest milk, protein and fat yields and with the highest milk protein percentage (p<0.01). The T allele had higher values than the C allele (p<0.05) except for fat percentage. The genotype CSN3 AA was associated with a significantly heightened milk yield; BB was associated with a high protein percentage. The effect of the alleles on the technological properties was not significant. The CSN2 BB genotype was associated with the best alcohol test (p<0.01), and the renneting order was inverse. Milk from cows with the CSN2 A1A1 genotype was best in the milk fermentation ability. CSN3 significantly affected the technological properties. Conclusion: The findings revealed the potential of some polymorphic loci for use in dairy cattle breeding and for the management of milk quality. In field research, the pivotal role of farms in milk yield, composition and technological properties was confirmed.

• Animal Bioscience
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• 제35권1호
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• pp.13-21
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• 2022

Objective: The aim of the study was to evaluate the influence of gene polymorphisms and nongenetic factors on the somatic cell score (SCS) in the milk of Holstein (n = 148) and Simmental (n = 73) cows and their crosses (n = 6). Methods: The SCS was calculated by the formula SCS = log₂(SCC/100,000)+3, where SCC is the somatic cell count. Polymorphisms in the casein alpha S1 (CSN1S1), beta-casein (CSN2), kappa-casein (CSN3), beta-lactoglobulin (LGB), acyl-CoA diacylglycerol transferase 1 (DGAT1), leptin (LEP), fatty acid synthase (FASN), stearoyl CoA desaturase 1 (SCD1), and 1-acylglycerol-3-phosphate O-acyltransferase 6 (AGPAT6) genes were genotyped, and association analysis to the SCS in the cow's milk was performed. Further, the impact of breed, farm, year, month of the year, lactation stage and parity on the SCS were analysed. Phenotype correlations among SCS and milk constituents were computed by Pearson correlation coefficients. Results: Only CSN2 genotypes A¹/A² were found to have significant association with the SCS (p<0.05), and alleles of CSN1S1 and DGAT1 genes (p<0.05). Other polymorphisms were not found to be significant. SCS had significant association with the combined effect of farm and year, lactation stage and month of the year. Lactation parity and breed had not significant association with SCS. The phenotypic correlation of SCS to lactose content was negative and significant, while the correlation to protein content was positive and significant. The correlations of SCS to fat, casein, nonfat solids, urea, citric acid, acetone and ketones contents were very low and not significant. Conclusion: Only CSN2 genotypes, CSN1S1 and DGAT1 alleles did show an obvious association to the SCS. The results confirmed the importance of general quality management of farms on the microbial milk quality, and effects of lactation stage and month of the year. The lactose content in milk reflects the health status of the udder.

• 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.