• 한국축산식품학회지
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• 제30권1호
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• pp.102-109
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• 2010

재고 분유를 이용하기 위하여 유청 배출없이 전지 분유와 발효유를 혼합하여 모조 치즈를 제조하였으며, 숙성 환경과 숙성 기간의 차이를 관찰하여 자연 치즈와 유사한 성질을 나타내는 최적의 숙성 조건을 규명하기 위하여 수분함량 변화, 일반성분, 비카제인태 질소화합물, 비단백태 질소화합물 그리고 유리 아미노산 등의 변화를 관찰하였다. 본 모조 치즈는 제조 후 건조 1일째가 수분함량이 40.27%로 가장 적합하였고, 이들은 진공 포장한 후 $12^{\circ}C$에서 숙성하는 방법과 P. camemberti 곰팡이를 분무한 후 $12^{\circ}C$, 95% RH에서 숙성하는 두 가지 방법으로 숙성하였다. 곰팡이 숙성 시 유당 함량이 24.64%에서 4주 숙성 시 5.43%로 급격히 감소하는 현상이 있었으나 진공 포장 숙성 시에는 유당의 변화가 심하지 않았다. 또한 진공 포장 숙성 시 비카제인태 질소 및 비단백태 질소는 숙성 4주 이후에 각각 28.10 mg/mL에서 50.61 mg/mL으로, 6.58 mg/mL에서 21.59 mg/mL으로 증가하였으며, 곰팡이 숙성 시 비카제인태 질소 및 비단백태 질소는 숙성 4주 이후에 각각 28.10 mg/mL에서 54.05 mg/mL으로, 6.58 mg/mL에서 23.06 mg/mL으로 증가하였다. 진공 포장 숙성 시 4주간의 유리 아미노산 차이를 측정한 결과, arginine, tyrosine, leucine이 두드러진 증가를 보였다. 그리고 총 유리 아미노산이 7.73 nmol/mg에서 9.29 nmol/mg으로 증가하였고, bitter amino acid는 1.36 nmol/mg에서 2.43 nmol/mg으로 증가하였다. 또한 곰팡이 숙성 시 4주간의 유리 아미노산을 측정한 결과, asparagine을 제외한 모든 유리 아미노산이 두드러진 증가를 보였다. 총 유리 아미노산이 8.40 nmol/mg에서 34.87 nmol/mg로 증가하였고, bitter amino acid는 1.53 nmol/mg에서 10.02 nmol/mg로 증가하였다. 치즈 유사품 제조 시에 P. camemberti를 이용한 치즈가 P. camemberti 를 이용하지 않는 치즈보다 단백질 분해 정도나 풍미가 더 우수한 것으로 나타났다.

• Asian-Australasian Journal of Animal Sciences
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• 제22권11호
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• pp.1504-1512
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• 2009

A feeding trial was conducted to examine the effect of high-temperature-micro-time (HTMT) processing of diets containing extruded soybean (ESB) in high quantity on milk fat production, metabolic responses, and the formation of conjugated linoleic acid (CLA) and trans-vaccenic acid (TVA). Twenty-one multiparous Holstein cows in mid-lactation were blocked according to milk yield in the previous lactation. Cows within each block were randomly assigned to either normal concentrate or HTMT treated diets containing ESB (7.5% HTMT-ESB and 15% HTMT-ESB). It was hypothesized that the HTMT-ESB would affect the undegradable fatty acids in the rumen and, thus, would modify the fatty acid profile of milk fat. Both 7.5% and 15% HTMT-ESB did not affect milk yield, fat, protein, lactose and solid-not-fat (SNF), but the proportion of cis-9, trans-11 CLA in milk fat was significantly increased by these treatments. Content of TVA in milk fat was not affected by HTMT-ESB. The HTMT-ESB influenced the fatty acid profile in milk fat, but there was little difference between 7.5% and 15% of supplementation. HTMT-ESB feeding significantly decreased the concentration of plasma insulin and glucose, while plasma growth hormone (GH), triglyceride (TG), non-esterified fatty acid (NEFA) and HDLcholesterol were increased by 7.5% and 15% ESB-HTMT supplementation in comparison to the control group (p<0.05). However, no significant difference was observed in plasma LDL-cholesterol, insulin like growth factor (IGF)-1, T3, T4, and leptin concentrations among treatments (p>0.05). The present results showed that cis-9, trans-11 CLA production was increased by HTMT treatment of dietary ESB without reduction of milk fat, and the unchanged milk fat and yield was assumed to be associated with the constant level of thyroid hormones, leptin, and IGF-1.

• Asian-Australasian Journal of Animal Sciences
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• 제18권10호
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• pp.1425-1429
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• 2005

Megaspahera elsdenii YJ-4, which was previously isolated as a producer of trans-10, cis-12 CLA, was studied for its carbon source on the CLA production. M. elsdenii YJ-4, was incubated with glucose and lactose, and cultured in batch and continuous culture systems with linoleic acid at various pHs to investigate CLA production. Batch cultures of the ruminal bacterium, M. elsdenii YJ-4, were resistant to stearic acid and linoleic acid, and little growth inhibition was observed even when the fatty acid concentration in the culture was as much as 4 mg $ml^{-1}$. Stationary phase batch cultures (0.25 mg bacterial protein $ml^{-1}$) that had been grown on lactate and incubated with linoleic acid (0.20 mg $ml^{-1}$) produced approximately 12 ${\mu}g$ trans-10, cis-12 CLA mg $protein^{-1}$ and little cis-9, trans-11 CLA was detected. Some linoleic acid was converted to hydrogenated products (chiefly stearic acid), but these fatty acids were less than 5 ${\mu}g$ mg bacterial $protein^{-1}$. Stationary phase batch cultures that had been grown on glucose produced at least 3-fold less trans-10, cis-12 CLA than ones grown on lactate. Cells from lactate-limited continuous cultures produced less trans-10, cis-12 CLA than those from batch culture, but only if the pH was greater than 6.4. When the pH of the lactate-limited continuous cultures was lower than 6.4, trans-10, cis-12 CLA and hydrogenated products declined. Cells from glucose-limited continuous cultures produced less trans-10, cis-12 CLA and hydrogenated products than the cells that had been limited by lactate, but pH had little impact on this production. These results support the idea that M. elsdenii YJ-4 could be one of the major producers of trans-10, cis-12 CLA which causes cows to produce milk with a low fat content.

• Applied Biological Chemistry
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• 제26권4호
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• pp.205-210
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• 1983

유청(乳淸)과 대두(大豆) 단백질(蛋白質) 공동침전(共同沈澱)에 의해 제조된 아미노산 강화두부(强化豆腐)의 특성(特性)을 조사하기 위하여 유청(乳淸)또는 유청분말(乳淸粉末)과 두유(豆乳)를 혼합하여 두부를 제조하고 이때 얻어지는 강화 두부의 일반조성, 아미노산 조성을 분석하고 물리적 특성도 비교하였다. 강화 두부는 외관이나 특성(特性)에서 재래식 두부와 큰 차이가 없었다. 전고형분 함량은 재래식 두부가 약 19%, 강화 두부가 17.3$\sim$18.1%이고 단백질 함량은 재래식 두부가 13.1% 강화 두부의 경우 10.9$\sim$11.4%로서 모두 재래식 두부가 높았다. 유청의 조지방(粗脂肪) 함량(含量)이 낮으므로 유청의 혼합비율이 높아질수록 두부 중 지방함량은 낮아졌으며 유청(乳淸) 두유(豆乳) 혼합물 중의 유당은 5$\sim$15%가 강화 두부에 이행되었다. 유청과 두유를 3:1로 혼합하여 제조한 경화 두부의 함유황(含硫黃) 아미노산 함량은 3.80g/100g 단백질로서 재래식 두부의 2.54g에 비해 약 50% 강화효과를 보였다.

• 한국수산과학회지
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• 제14권3호
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• pp.139-147
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• 1981

식품 방부제인 2-(2-furyl)-3-(5-nitro-2-furyl) acrylamide의 사용이 금지된 후로 어묵 및 어육햄(ham) 및 소시지(sausage) 등의 보존성을 높이기 위한 수단의 하나로 제품의 $a_w$치를 0.94이하로 떨어뜨리는 방법이 권장되고 있다. 본 연구에서는 포장 어묵을 제조할 때에 수분량을 일정하게 조정하여 식염, 당류 및 다가알코올류를 첨가하였을 경우 제품에 미치는 첨가제의 수분 활성저하 효과를 조사하였다. 1. 식염은 $4\%$이상 첨가하면 $a_w$를 0.94이하로 저하시킬 수 있었다. 그러나, 제품의 맛을 고려할 때 실용성이 없을 것으로 생각된다. 2. sucrose, lactose, maltose보다 g1ucese의 수분활성 저하 효과는 현저히 컸으나 갈변을 유발하므로 다량 첨가는 문제가 될 것으로 생각된다. 3. glycerin, sorbitol 및 propylene glycol 등의 다가알코올류는 대체로 수분 활성 저하 효과가 좋았다. 그 효과는 glycerin, propylene glycol, sorbitol의 순이었고, 특히 glycerin은 효과가 좋아서 식염의 1/3정도의 저하 효과가 있었다. 4. 동일 첨가제에 있어서는 제품의 수분함량이 저하 경우가 수분 활성 저하 효과가 다소 나은 경향을 보였다.

• 농업과학연구
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• 제14권2호
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• pp.301-308
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• 1987

국산우유(國産牛乳)의 적정(適正) 살균조건(殺菌條件)을 구명(究明)하고자 $50^{\circ}C$로부터 $70^{\circ}C$까지 $5^{\circ}C$ 간격으로 가열처리(加熱處理)하고 처리유(處理乳)의 화학적조성(化學的組成) 및 미생물학적(薇生物學的) 성상(性狀) 변화(變化)를 확인함과 동시(同時)에 처리유(處理乳)의 보존성(保存性)을 시험(試驗)한 결과(結果) 다음과 같다. 1. $50^{\circ}C{\sim}70^{\circ}C$의 가열처리(加熱處理)에 의하여 우유(牛乳)의 pH 6.55로부터 6.42로 감소(減少)하였으며, 단백질(蛋白質), 지방(脂肪), 유당(乳糖) 및 회분(灰分)은 함량(含量)이 별로 변화(變化)하지 않았다. 2. 가열온도(加熱溫度)의 상승(上昇)에 따라 비(非) casein 태질소(態窒素) 및 여과성질소량(濾過性窒素量)은 감소(減少)하였으며 casein 태질소(態窒素)와 비단백태질소(非蛋白態窒素)는 증가(增加)하였다. 3. 가열온도(加熱溫度)의 상승(上昇)에 따라 우유중(牛乳中)의 Calcium 및 Vitamin C는 감소(減少)하였으며 가열처리유(加熱處理乳)의 인공소화율(人工逍化率)은 처리전(處理前)의 14.07%로부터 20.00%로 증가(增加)하였다. 4. $65^{\circ}C$의 가열살균(加熱殺菌)에 의하여 생균수(生菌數)는 $1.3{\times}10^4/m{\ell}$, 대장균수(大腸菌數)는 음성(陰性), 호냉성균수(好冷性菌數)는 $9.5{\times}10^2/m{\ell}$를 나타냈으며 99%의 살균율(殺菌率)을 표시(表示)하였다. 5. $65^{\circ}C$에서 가열살균(加熱殺菌)한 처리유(處理乳)는 $4^{\circ}C$의 냉장보존(冷藏保存)에서 화학적조성(化學的組成) 성상(性狀)의 변화(變化)가 적었다.

• Journal of Dairy Science and Biotechnology
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• 제31권1호
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• pp.21-33
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• 2013

The purpose of this study was to improve the production of Mozzarella cheese analogues manufactured using mixtures of soy milk and concentrated raw milk by performing ultrafiltration (UF) and to assess the quality of these cheeses during a 30-day storage period at $4^{\circ}C$, relative to that of Mozzarella cheese manufactured with the traditional method. The solid consistency of Mozzarella cheese analogue prepared from milk mixtures was lower than that of cheese manufactured from raw milk or soy milk and increased during storage, which is considered to be the result of decreasing water levels, as well as with increasing soy milk concentrations. In the Mozzarella cheese analogue generated using the milk mixtures, the fat content decreased with increase in the soy milk concentration, while it decreased during the storage period. Lactose levels were lowest in cheese composed of soy milk or raw milk and processed by UF, and decreased during storage in cheese produced using milk mixtures. In milk mixtures containing soy milk, the protein concentration increased with increasing amounts of raw milk and did not change during the storage period. The water-soluble nitrogen compound level was similar between cheeses and increased only slightly during storage. The amount of non-protein nitrogen compounds was higher in the cheese analogue than in the control cheese and tended to increase during storage. Analysis of the physicochemical traits of the Mozzarella cheese analogue yielded the following results: During storage, titratable acidity levels increased while pH tended to decrease. After analysis using electropherograms, it was classified as ${\alpha}$-, ${\beta}$-, or ${\kappa}$-casein. The results of rheometry tests showed that in the Mozzarella cheese analogue prepared from milk mixtures, with raw milk concentrated by UF, increases in concentration rate lead to lowered hardness, elasticity, cohesiveness, and brittleness. When cheese was produced from milk mixtures and concentrated by UF, meltability increased as the concentration rate increased, although to an extent that was less than that observed for the control cheese, and tended to increase during storage. Sensory evaluation showed that the analogue cheese was much better than the control cheese in terms of formation, appearance, and flavor.

• Asian-Australasian Journal of Animal Sciences
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• 제23권10호
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• pp.1319-1324
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• 2010

The objectives of this study were to compare the effectiveness of different indicators of mammary inflammation in buffalo and to evaluate the association of the indicators with buffalo milk yield, composition, and rennet coagulation properties. This study was carried out at four buffalo farms in central Italy using a total of 50 lactating buffalo. Milk from each buffalo was tested at the beginning, middle, and end of lactation. To evaluate the relationship between mastitis markers and milk components, three classes were defined for each of the following markers: total somatic cell count (TSCC), differential somatic cell count (DSCC), and bacteriological results The regression coefficient for the reference method and the alternative method of determining TSCC was 0.81, indicating that the method routinely used to analyze buffalo milk consistently underestimated actual TSCC. The milk samples positive for udder-specific bacteria also had higher TSCC values than the samples that were negative for bacteria ($872{\times}10^3$/ml vs. $191{\times}10^3$/ml). In samples that were positive for udder-specific bacteria, polymorphonuclear leukocytes (PMN) made up greater than 50% of the cells. Moreover, only 1% of the samples in the lowest TSCC class were positive for bacteria. The correlation between TSCC and PMN was stronger (0.70), and PMN values in buffalo milk increased significantly when the TSCC class changed from low (38%) to medium and high (56% and 64%). Milk yield was negatively related to TSCC. Significant changes in lactose (4.87%, 4.80% and 4.64%) and chloride content (0.650 mg/ml, 0.862 mg/ml and 0.882 mg/ml) were also observed with increasing TSCC values. Higher TSCC was associated with impaired rennet coagulation properties: the clotting time increased, while the curd firming time ($p{\leq}0.05$) and firmness decreased. We concluded that in buffalo as in dairy cows, TSCC is a valid indicator of udder inflammation; we also confirmed that a value of $ 200{\times}10^3 cells/ml should be used as the threshold value for early identification of an animal affected by subclinical mastitis. In addition to its association with significantly decreased milk yield, a TSCC value above this threshold value was associated with changes in milk composition and coagulating properties.

• Asian-Australasian Journal of Animal Sciences
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• 제14권8호
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• pp.1138-1143
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• 2001

A total of 96 piglets were weaned at 19 and 13 days in Exp. 1 and 2, respectively, and allotted to one of four diets: three with different spray dried plasmas (SPs) and one with hydrolysed casein (HC). SPs were from pigs (SPP), mixed origin (SMP), and mixed origin with standardized level of immunoglobulins (SMPIG). All the diets contained 1.7% total lysine, 25% of the test protein source, 45% corn starch, 15% lactose, 2% sucrose, 7% soybean oil. At d 4 and d 2 in Exp. 1 and 2, respectively, piglets were perorally challenged with $10^{10}$ CFU E. coli K88. Growth performance, immunity, and health condition were measured for 15 days and 14 days in Exp. 1 and 2, respectively. To investigate apparent ileal digestibility and nutrient deposition, all piglets were sacrificed at d 14 in Exp. 2. In 1. 3 piglets died in HC diet and 1 in SPP diet. HC diet showed higher mortality (p<0.01) than other diets. In Exp. 2, no clinical sign of infection was detected, no difference for the content of E. coli K88 was found in feces at 4 and 6 days after the infection, and no E. coli K88 was found in the jejunum at the end of experiment. In both experiments, feed intake was lower for HC diet and ADG was 96, 106, 122 and 155 for HC, SPP, SMP and SMPIG diet, respectively (HC vs others, p<0.05; SMPIG vs other SP, p<0.01). Heal apparent digestibility of nitrogen in sacrificed piglets was higher for HC diet (p<0.05). After the challenge, K88-specific titers in saliva (Exp. 1) and in plasma (Exp. 2) were reduced in SMP and SMPIG. The piglets positive to the adhesion of the used E. coli strain to the intestinal brush borders had a significantly reduced growth (p<0.01) and a higher K88-specific IgA titer in plasma, in comparison with negative ones. This effect was independent of the diet. The data show the relevance of spray dried plasma sources and particularly of SP with standardized level of immunoglobulins for the feeding of early-weaned at the risk of infection by enterotoxigenic bacteria.

• Asian-Australasian Journal of Animal Sciences
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• 제30권10호
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• pp.1416-1424
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• 2017

Objective: The objective of this study was to examine the effects of alfalfa flavonoids on the production performance, immunity, and ruminal fermentation of dairy cows. Methods: The experiments employed four primiparous Holstein cows fitted with ruminal cannulas, and used a $4{\times}4$ Latin square design. Cattle were fed total mixed ration supplemented with 0 (control group, Con), 20, 60, or 100 mg of alfalfa flavonoids extract (AFE) per kg of dairy cow body weight (BW). Results: The feed intake of the group receiving 60 mg/kg BW of AFE were significantly higher (p<0.05) than that of the group receiving 100 mg/kg BW. Milk yields and the fat, protein and lactose of milk were unaffected by AFE, while the total solids content of milk reduced (p = 0.05) linearly as AFE supplementation was increased. The somatic cell count of milk in group receiving 60 mg/kg BW of AFE was significantly lower (p<0.05) than that of the control group. Apparent total-tract digestibility of neutral detergent fiber and crude protein showed a tendency to increase (0.05<$p{\leq}0.10$) with ingestion of AFE. Methane dicarboxylic aldehyde concentration decreased (p = 0.03) linearly, whereas superoxide dismutase activity showed a tendency to increase (p = 0.10) quadratically, with increasing levels of AFE supplementation. The lymphocyte count and the proportion of lymphocytes decreased (p = 0.03) linearly, whereas the proportion of neutrophil granulocytes increased (p = 0.01) linearly with increasing levels of dietary AFE supplementation. The valeric acid/total volatile fatty acid (TVFA) ratio was increased (p = 0.01) linearly with increasing of the level of AFE supplementation, the other ruminal fermentation parameters were not affected by AFE supplementation. Relative levels of the rumen microbe Ruminococcus flavefaciens tended to decrease (p = 0.09) quadratically, whereas those of Butyrivibrio fibrisolvens showed a tendency to increase (p = 0.07) quadratically in response to AFE supplementation. Conclusion: The results of this study demonstrate that AFE supplementation can alter composition of milk, and may also have an increase tendency of nutrient digestion by regulating populations of microbes in the rumen, improve antioxidant properties by increasing antioxidant enzyme activities, and affect immunity by altering the proportions of lymphocyte and neutrophil granulocytes in dairy cows. The addition of 60 mg/kg BW of AFE to the diet of dairy cows was shown to be beneficial in this study.