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用单向免疫扩散法检测IgG含量,评价了脱脂、去除酪蛋白等乳清制备工艺和热消毒处理对IgC的影响.结果表明,脱脂和去除酪蛋白可造成IgG损失4.5%～11.5%,平均损失为(6.1±4.8)%;低温巴氏杀菌使乳清IgG损失8.0%～18.8%,平均损失为(11.7±7.8)%;(75±2)℃ 15 s和(80±2)℃10 S处理初乳样均未检出IgG,与相关文献报道不一致;UHT处理常乳,未栓出IgG.酸凝固去除酪蛋白与热处理有交互作用,增强了对IgG的破坏,与凝乳酶凝固去酪相比IgG多损失2.1%～4.3%,平均多损失为(3.5±3.4)%. 相似文献
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超滤法对牛初乳中IgG含量和活性的影响 总被引：3，自引：1，他引：2
本文研究了超滤分离牛初乳乳清中IgG的方法，测定不同超滤温度和压力条件下IgG含量和活性的变化情况。结果表明：通过超滤可将乳清中IgG含量提高一倍左右；超滤压力增加，IgG含量相应增加．IgG活性基本不变。在压力0．08MPa时，IgG含量为45．98mg／mL，活性未变，仍为1024；超滤温度增加，初乳中的IgG含量先有较小增加然后减少，IgG活性则下降。在超滤温度40℃时，IgG含量最高，达到46、85mg／mL，IgG活性未有变化。 相似文献
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乳酸菌发酵牛初乳的研究 总被引：1，自引：0，他引：1
本文提出了乳酸菌发酵牛初乳产品的生产工艺，测定了发酵初乳过程中IgG含量和活性的变化等。结果表明：脱脂初乳在80℃／15s和95菌／15s的杀菌条件下IgG含量分别较65菌／30min减少了51．19％和85．38％，损失较大。由于乳酸菌发酵产酸导致pH值降低，发酵初乳IgG活性也相应降低，其IgG活性降低至25％，在冷藏24h、48h后活性基本未变化。发酵初乳较普通酸奶颜色微黄、微涩、有腥味，凝乳时间比普通酸奶多出2，5h左右。 相似文献
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针对9种常见肠道致病菌的免疫乳的研究 总被引：11，自引：4，他引：7
以9株人肠道病原菌(致病大肠杆菌3株、志贺氏菌3株、沙门氏菌3株)制备的混合抗原对孕牛进行系统免疫，以获得对人致病肠道杆菌具有特异性的牛乳抗体。对母牛进行系统免疫后，免疫乳和非免疫乳中IgG总含量没有显著变化。但经免疫处理的母牛，其初乳(产犊后24h内)中针对9种致病肠道杆菌的特异性IgG效价为2^10-2^12，而非免疫母牛为2^7-2^10，免疫处理后初乳中特异性IgG效价提高了2—9倍；经免疫处理的母牛，其常乳中针对9种致病肠道杆菌的特异性IgG效价为2^6-2^10，而非免疫母牛为2^1-2^6，免疫处理后常乳中特异性IgG效价提高了8-14倍。对免疫乳中IgG热致变性进行研究，其结果为：经60℃、10min，60℃、30min，70℃、10min，70℃、30min，80℃、10min，80℃、30min加热处理，免疫乳中IgG变性率分别为14．81％、25．20％、76．44％、85、58％、100％、100％。对免疫乳中IgG酸稳定性进行研究，其结果为：经pH2、10min，pH2、30min，pH4．5、60min，pH4．5、120min处理，免疫乳中IgG活性持留率分别为66.69％、56．55％、100％、100％。 相似文献
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探寻一种准确测定牛初乳中IgG含量的前处理方法及液相色谱分离条件,选用超声波、生理盐水、盐酸和乳酸作为去除乳脂和酪蛋白沉淀的前处理条件;选用反相键合色谱柱ZORBAX 300SB-C18和ZORBAX Poroshell 300SB-C18,流动相为0.02 mol/L PBS与乙腈作为色谱分离条件对初乳清进行分离;并测定其精密度和回收率.试验结果表明：选用超声波40 kHZ、45 min时,牛初乳中IgG含量达到最高,比没有经过超声处理的IgG含量提高近两倍;选用乳清与生理盐水的稀释比例为1：7时,牛初乳中IgG含量达到最高;选用乳酸调pH值至4.6时,可以更好的去除酪蛋白沉淀;选用反相键合色谱柱ZORBAX 300SB-C18,流动相0.02 mol/L PBS（pH 6.8）与乙腈的比例为95：5、流速为0.2 mL/min时,初乳各蛋白组分分离效果达到最佳.所测定的精密度和回收率分别为0.11%和99.96%. 相似文献
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实验室制备牛奶酪蛋白的技术研究 总被引：1，自引：0，他引：1
对影响酪蛋白提取收得率和制品纯度的各种因素进行试验研究.确定了实验室条件下从牛奶中提取酪蛋白的技术路线和工艺参数.离心转速为5 000 r/min,离心时间为30 min,进行离心脱脂;在预热温度55℃、pH值为4.6的条件下进行酪蛋白凝聚;离心排除乳清,转速为3 000 r/min,时间为15min,经水洗涤后50℃条件下烘干3.5h,用石油醚作为有机溶剂进行抽提,最终得到纯度为95%左右的酪蛋白制品. 相似文献
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本研究旨在对超速离心法和酸沉淀法鉴定的乳清蛋白进行分析,并比较不同样品制备方法对乳清蛋白组鉴定结果的影响。采集牛奶样品去除脂肪,利用超速离心和酸沉淀法制备乳清蛋白,液相色谱串联质谱分析结合数据库搜索鉴定,比较两种方法制备的乳清蛋白的差异,分析了差异蛋白参与的生物过程、细胞组成和分子功能等。聚类分析和主成分分析展示了两种样品制备方法的差异蛋白,超速离心方法鉴定的表达量增加的蛋白有53个,包括β-酪蛋白、糖基化依赖细胞黏附分子1和多聚免疫球蛋白受体等;酸沉淀方法鉴定的表达量增加的蛋白有21个,包括CD9抗原、β2-微球蛋白和β-乳球蛋白等。将两种方法获得的差异蛋白根据蛋白注释分类发现,超速离心法中高表达的蛋白主要位于胞外区域、囊泡、内膜系统、内质网和高尔基体等,涉及蛋白结合、酶调节活性、受体结合和抗氧化活性等;酸沉淀法中高表达的蛋白主要位于胞外区域和囊泡等,涉及结合、核酸酶活性和离子结合等。结果提示,两种方法鉴定的蛋白质组表达模式存在差异,乳清蛋白样品制备方法的结合可以获得更多的鉴定蛋白,为乳清蛋白组学研究中样品制备方法的选择提供参考依据。 相似文献
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为探讨抗犊牛肺炎支原体免疫初乳乳清的制备方法,本试验采用牛支原体灭活佐剂疫苗于经产前2～4周给怀孕母牛免疫接种2次,制备高免初乳,收集产后12 h之内的初乳,分别采用离心沉淀与过滤法制备脱脂初乳,采用不同的酸化法、酶化法、酸和酶结合法制备乳清,通过紫外分光光度计及ELISA方法检测乳清中的总蛋白含量及抗牛支原体抗体滴度。结果显示,4 ℃、3500 r/min离心30 min对初乳的脱脂效果最好,初乳总蛋白含量及抗牛支原体抗体滴度损失最少;酶和酸结合法的乳清析出率最高,维生素C（0.2 g/mL）处理法对脱脂初乳中蛋白损失最小,盐酸处理法对脱脂初乳中抗牛支原体抗体滴度损失最小。结果表明用0.6 mol/L盐酸调pH至4.6,室温下放置30 min,10000 r/min离心20 min是高免初乳乳清制备的适宜方法。 相似文献
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The association of purified, iodinated bovine immunoglobulins with the various fractions of whole milk and with cell-free skim milk and with two different mammary cell populations was studied. Associations in whole milk were concentration independent over a 6-fold range and revealed that SIgA and IgM were 5-fold more prevalent in milk fat than IgG1 and IgG2; the concentration of IgM and SIgA was 3-fold and 2-fold higher in fat than whey, respectively. A significant proportion of the IgM, ca 20% and to a lesser extent IgG2, ca 10%, were found in association with the casein pellet. Greater than 85% of the IgG2, greater than 90% of the IgG1, approximately equal to 80% of the SIgA and 70% of the IgM were found in milk whey. Isoelectric precipitation of casein significantly reduced the amount of IgM which associated with fat. When labelled Igs were incubated with milk leukocytes alone, only SIgA and IgM became significantly associated with them. However, when 10(6) cells were added, the amount of SIgA and IgM in the casein-cell pellet was not additive, although the increase for IgM was significant. These Igs also associated with the casein pellet of cell-free skim milk. When whole milk was used, the milk fat competed with cells and casein for association with SIgA and IgM. Homogenization of the fat layer from normal milk with or without added cells, caused significant release of the Igs which sedimented in the pellet. 相似文献
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本文对采自香格里拉地区的牦牛＂奶渣＂（是提取乳脂肪后的牦牛乳成分经压榨而成）鲜样、发酵样、干样进行理化分析,并对鲜、干＂奶渣＂加工干酪素的工艺进行了研究。结果表明,香格里拉鲜＂奶渣＂蛋白质含量为19.64%,脂肪为2.40%,水分为74.40%,灰分为1.1%,钙为0.47%,磷为0.17%,酸度为54°T,pH值为3.66。通过正交试验筛选出以鲜＂奶渣＂生产干酪素的最佳工艺参数为离心脱脂转速为4 000r/min、离心5min、干燥10h（60℃）,干酪素成品率34.18%;筛选出以干＂奶渣＂生产干酪素的最佳工艺参数离心脱脂转速为5 000r/min、离心时间为5min、干燥时间为15h（60℃）,成品率达83.40%。经测定成品符合QB/T 3780—1999工业干酪素的要求。 相似文献
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Purified, iodinated bovine immunoglobulins (Igs) were incubated with fresh Guernsey milk or with the casein, fat and whey fraction of such milk for up to 12 hr at 37 degrees C. Igs incubated in whole milk, showed little evidence of proteolysis in either the whey, fat or casein fractions although the amount of radioactivity which became associated with the latter two fractions prevented adequate analysis. When the individual milk fractions were first prepared and then incubated with iodinated Igs, we found no evidence for proteolysis of any Ig in whey or casein but ca. 25% breakdown or dissociation of the IgM and SIgA which had been incubated with milk fat. Breakdown of these Igs in fat was not inhibited with benzamidine-HCl, sodium azide or EDTA. These data show that: only those Igs which associate with milk fat are degraded or dissociated by it and the Ig fragments described from cows milk or recovered during studies on Ig transport cannot be ascribed to the proteolytic activity of fresh milk. 相似文献
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本研究旨在对超速离心法和酸沉淀法鉴定的乳清蛋白进行分析,并比较不同样品制备方法对乳清蛋白组鉴定结果的影响。采集牛奶样品去除脂肪,利用超速离心和酸沉淀法制备乳清蛋白,液相色谱串联质谱分析结合数据库搜索鉴定,比较两种方法制备的乳清蛋白的差异,分析了差异蛋白参与的生物过程、细胞组成和分子功能等。聚类分析和主成分分析展示了两种样品制备方法的差异蛋白,超速离心方法鉴定的表达量增加的蛋白有53个,包括β-酪蛋白、糖基化依赖细胞黏附分子1和多聚免疫球蛋白受体等;酸沉淀方法鉴定的表达量增加的蛋白有21个,包括CD9抗原、β2-微球蛋白和β-乳球蛋白等。将两种方法获得的差异蛋白根据蛋白注释分类发现,超速离心法中高表达的蛋白主要位于胞外区域、囊泡、内膜系统、内质网和高尔基体等,涉及蛋白结合、酶调节活性、受体结合和抗氧化活性等;酸沉淀法中高表达的蛋白主要位于胞外区域和囊泡等,涉及结合、核酸酶活性和离子结合等。结果提示,两种方法鉴定的蛋白质组表达模式存在差异,乳清蛋白样品制备方法的结合可以获得更多的鉴定蛋白,为乳清蛋白组学研究中样品制备方法的选择提供参考依据。 相似文献
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应用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳和体外模拟消化研究羊乳蛋白质组成和消化特性。结果表明：羊乳蛋白质主要由酪蛋白和乳清蛋白组成,酪蛋白主要由αs1-酪蛋白、αs2-酪蛋白、β-酪蛋白和κ-酪蛋白组成,在酪蛋白中的相对含量分别为23.10%、30.39%、38.09%和8.42%;乳清蛋白主要由α-乳白蛋白、β-乳球蛋白、乳铁蛋白、血清白蛋白和免疫球蛋白组成,在乳清蛋白中的相对含量分别为24.59%、57.50%、4.35%、8.69%和4.88%;羊乳酪蛋白主要在肠液中消化,在胃液中消化120 min时 相似文献
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J.G. Mohanty Y. Elazhary 《Comparative immunology, microbiology and infectious diseases》1989,12(4):153-160
Immunoglobulin G (IgG) from bovine serum raised against Aeromonas Salmonicida was purified by ammonium sulphate precipitation (ASP) or caprylic acid treatment followed by ammonium sulphate precipitation (CAAS). Purity of IgG samples prepared by both methods were examined by High Performance Gel Permeation Chromatography, electrophoresis and antibody activity assay. Results suggest that IgG prepared by ASP is better than that obtained by CAAS method in terms of the yield of the IgG monomers and the recovery of the antibody activity. 相似文献
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目的 为了提高云南乳饼副产物乳清液的附加值,使用喷雾干燥技术获得一种新型的高营养价值乳清粉。方法 以乳清液为原料,将溶解度和感官评分作为评价指标,利用单因素结合正交试验确定乳清粉研制最佳工艺条件。结果 当碳酸氢钠用量为0.7%,离心条件3 600 r/min,凝乳pH为6.5,喷雾干燥进风温度180 ℃,蠕动泵数值70 Hz时,研制出的乳清粉中蛋白质13.9%,乳糖49.4%,水分3.3%,灰分6.8%,理化指标及微生物检测结果均符合国标,该乳清蛋白粉溶解性95.18 g/100 g,乳化性72.07%,具有诱人的奶香味,无酸味、异味,色泽呈现均一的淡黄色,口感丝滑,复水性较好。结论 此试验研究为乳饼副产物乳清液的利用提供了途径,为乳清粉的深加工提供了一定的理论依据和参考。 相似文献
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K L Anderson A R Smith R D Shanks H L Whitmore L E Davis B K Gustafsson 《American journal of veterinary research》1986,47(11):2405-2410
Milk whey immunoglobulins (Ig) and phagocytosis of staphylococci by milk polymorphonuclear neutrophilic leukocytes (PMN) were measured in 12 cows (allotted to 6 pairs) during acute bovine mastitis induced by intramammary inoculation of endotoxin. Six of these cows (or 1 in each pair) were treated with flunixin meglumine and were compared with the others (given only saline solution). The endotoxin inoculation comprised 10 micrograms of Escherichia coli O26:B6 lipopolysaccharide injected into one of the rear quarters (mammae). Flunixin meglumine was administered parenterally at a dosage of 1.1 mg/kg every 8 hours (total of 7 doses) beginning at 2 hours after endotoxin was injected. Milk samples were obtained, and whey samples were prepared from each quarter of each cow 3 times before inoculation and at 2, 4, 8, 12, 24, 48, 72, 96, 120, 144, 168, and 336 hours after endotoxin was inoculated. Significant increases (P less than 0.05) in milk whey IgG1, IgG2, IgM, and IgA concentrations were observed in whey samples from endotoxin-inoculated quarters. Greatest relative increase was seen for IgG2. Increased whey Ig concentrations were not observed in quarters which were not inoculated with endotoxin. Concentrations of whey IgG1 and IgM in endotoxin-inoculated quarters were significantly (P less than 0.05) decreased in flunixin meglumine-treated cows, compared with those in saline solution-treated cows. Significant increases in phagocytosis of staphylococci by milk PMN were observed in whey samples from endotoxin-inoculated quarters. Significant differences in PMN phagocytosis were not found in whey samples from cows given flunixin meglumine when compared with whey samples from cows given saline solution. 相似文献