食品添加剂对牛初乳免疫球蛋白(IgG)稳定性的影响

探讨了几种常用食品添加剂对牛初乳免疫球蛋白稳定性的影响,根据食品添加剂对IgG的变性率的影响,选择了几种在食品加工中常用的添加剂进行正交试验,考察其相互综合作用。结果表明:随着柠檬酸、乳酸和磷酸二氢钠浓度的增大,免疫球蛋白的稳定性逐渐降低,变性率逐渐增大;山梨酸钾对免疫球蛋白的稳定性影响较小;磷酸氢二钠、乳酸钙、增稠剂和甜味剂对免疫球蛋白有一定的保护作用。添加剂最佳用量为:乳酸用量为0.3%,乳酸钙用量为0.015%,黄原胶用量为0.5%,蔗糖用量为8%,此时IgG的变性率为14.7%,在4℃的贮藏条件下最佳保存期为30天。     

羊初乳热稳定性研究初探

本文以不同泌乳期的羊初乳为原料,研究了不同泌乳期的初乳的热稳定性,以及酸度,添加物磷酸盐、柠檬酸盐、蔗糖、钙离子、卡拉胶等对初乳热稳定性的影响。结果表明:初乳的热稳定性随泌乳期和pH值的增大而增大;磷酸盐、柠檬酸盐、蔗糖均对初乳的热稳定性有改善作用;而钙离子、卡拉胶使初乳的热稳定性下降。在80℃下初乳热稳定性改善最适条件为:pH6.9,柠檬酸0.02mol/L,磷酸盐0.2mol/L,蔗糖30%。     

初乳中免疫球蛋白的研究进展

初乳富含多种营养成分和活性物质,特别是含有大量的免疫球蛋白。本文就初乳中免疫球蛋白的基本结构、性质、测定方法、生物功能、水平及开发现状等方面进行了综述。     

牛初乳免疫球蛋白变性动力学研究

测定了牛初乳（３￣７２ｈ）７个不同泌乳期免疫球蛋白（ＩｇＧ）的含量，研究了ｐＨ值对免疫球蛋白变性的影响，并着重考查了５５，６０，６５℃温度下ＩｇＧ随时间延长的变化规律，提出了其变性的动力学方程和其它热力学参数（活化能等），对变性率、温度和ｐＨ值之间的关系也给予扼要的说明。     

山羊初乳成分及其免疫球蛋白构成变化的研究

动物初乳对其后代健康的作用已经得到了广泛的证实,其对人类健康的影响也受到了越来越多的重视.本研究探讨了阿尔卑斯山羊产后一周内乳成分和其中免疫球蛋白(Ig)含量的变化.结果表明:产后48h内山羊奶的蛋白质、总固形物和免疫球蛋白含量均快速下降;脂肪含量在前三次的初乳中逐渐升高,随后又缓慢下降;乳糖含量保持相对稳定于4%～5%;经产山羊前三次初乳的蛋白含量分别达到了16.5%、10.7%和6.8%,显著地高于初产山羊前三次初乳的蛋白含量(7.0%、4.8%和4.1%);经产山羊前两次初乳的IgG含量达到了59.9mg/ml和34.7mg/ml,IgM含量达到了6.14mg/ml和2.37mg/ml,显著地高于初产山羊前两次初乳的IgG含量(18.1mg/ml和13.9mg/ml)和IgM含量(1.95mg/ml和0.98mg/m1);经产和初产山羊初乳的IgA含量无显著差异.     

金属螯合色谱分离提取初乳免疫球蛋白和乳铁蛋白

对金属螯合色谱分离提取初乳免疫球蛋白和乳铁蛋白的新工艺进行了研究,并采用SDS-PAGE电泳分析法测定了分离得到的免疫球蛋白和乳铁蛋白的含量。试验结果表明,采用金属螯合色谱可较好地分离提取免疫球蛋白,其纯度可达89%。同时还可分离得到副产品乳铁蛋白,但含量较低,仅为33%。另外还对影响螯合色谱分离的因素进行了初步的探讨。      

牛初乳免疫球蛋白体外稳定性研究

研究了牛初乳中免疫球蛋白的体外稳定性,包括热稳定性、酸碱稳定性、消化系统中的稳定性。牛初乳免疫球蛋白在不高于65℃范围内具有较高的稳定性,随温度升高残存率逐渐降低,当85℃、3min时IgG基本完全失活;牛初乳免疫球蛋白在pH<3.0和pH>11.0时稳定性较差,而在pH4.0～11.0之间具有较好的稳定性;在人工胃液中,pH值的影响最大,牛初乳添加量的影响次之;人工肠液中,胰蛋白酶是影响IgG活力的主要因子,消化时间次之,牛初乳添加量的影响最小。     

牛初乳免疫球蛋白稳定性研究概述

牛初乳富含很多营养成分,其中含有大量的免疫球蛋白,能够抵抗外界病毒侵害,增强机体自身免疫力,但在加工过程中,其活性受到很多因素影响。文中综述了温度、p H值、蛋白酶、超高压等因素对牛初乳免疫球蛋白稳定性的影响,对提高其稳定性的方法如食品添加剂保护法及微胶囊法的研究现状做出总结,为进一步开展牛初乳免疫球蛋白研究提供了参考。     

免疫初乳中IgG的分离与纯化

本实验采用硫酸铵一次性盐析、DEAE—Sepharose FF离子交换层析和Sephacryl S-200凝胶过滤层析法，分离纯化免疫初乳中的IgG，并采用SDS—PAGE电泳、单向火箭免疫电泳及试管凝集法对IgG分离物进行了定性定量检测，结果表明所得IgG纯度高，活性大。     

关于免疫乳与初乳

本文综述了免疫乳和初乳的发展、制备和作用,分析了免疫乳和初乳存在的问题,提出免疫乳与牛初乳只能作为增强肠道局部免疫的保健食品,但对预防肠道传染病的时效性提出质疑,并指出长期服用可能会产生抗抗体的论点。     

牛初乳粉中免疫球蛋白热稳定性及热动力学的研究

通过测定牛初乳在不同温度下IgG的活性含量,研究了牛初乳粉中IgG对热的稳定性。利用Arrhenius方程,分析了牛初乳中IgG热变性过程中的热动力参数。研究表明,复原牛初乳IgG在<65℃范围内具有较高的稳定性。热动力学分析表明,复原牛初乳IgG热变性反应级数是1.1,在65,70,75,80,85,90℃的D值分别为188.68,34.36,6.18,3.07,1.80,0.95min,在65~90℃范围内的Z值为11.20℃,表观活化能Ea=216.41kJ/mol。     

Chitotriosidase activity in goat blood and colostrum

Chitotriosidase (ChT) activity has not been investigated in ruminants, and therefore, we studied this activity in blood and colostrum of 25 pregnant goats and 60 goat kids. Blood samples were taken from pregnant goats at 3, 2, and 1 d prepartum; at partum; and at 1, 2, 3, and 4 d postpartum. Colostrum samples were obtained by machine-milking at partum and 1, 2, 3, and 4 d postpartum. Goat kid blood was collected at birth and every 7 d thereafter until goats kids were 56 d old. The ChT activity ranged from 2,368 to 3,350 nmol/ mL per hour in goat blood serum, and no statistical differences were detected through time. However, activity tended to decrease from 3 d prepartum to 2 d post-partum. Colostrum ChT activity was 3,912 nmol/mL per hour and 465 nmol/mL per hour on the day of delivery and 4 d postpartum, respectively. Colostrum ChT activity was significantly higher at partum than at any other time. The ChT activity in colostrum was significantly greater at 1 d postpartum than at 2, 3, and 4 d postpartum. Chitotriosidase activity did not differ in colostrum collected on d 2, 3, and 4 postpartum. Chitotriosidase activity in goat kid blood serum ranged from 2,664 to 9,231 nmol/mL per hour at birth and 49 d of life, respectively. Chitotriosidase activity in the blood serum increased with age: at birth, activity was significantly less than at 28, 35, 42, 49, and 56 d postpartum. The maximum ChT activity in blood serum was observed at 49 d postpartum. Activity in 49-d-old kids was significantly greater than that observed in kids at 0, 7, and 14 d postpartum.     

Effects of enriching IgG concentration in low- and medium-quality colostrum with colostrum replacer on IgG absorption in newborn Holstein calves

Ingestion and absorption of greater quantities of IgG are required to increase serum IgG levels in newborn calves. This could be achieved by adding colostrum replacer (CR) to maternal colostrum (MC). The objective of this study was to investigate whether low and high-quality MC can be enriched with bovine dried CR to achieve adequate serum IgG levels. Male Holstein calves (n = 80; 16/treatment) with birth body weights (BW) of 40 to 52 kg were randomly enrolled to be fed 3.8 L of the following combinations: 30 g/L IgG MC (C1), 60 g/L IgG MC (C2), 90 g/L IgG MC (C3), C1 enriched with 551 g of CR (60 g/L; 30-60CR), or C2 enriched with 620 g of CR (90 g/L: 60-90CR). A subset of 40 calves (8/treatment) had a jugular catheter placed and were fed colostrum containing acetaminophen at a dose of 150 mg/kg of metabolic body weight, to estimate abomasal emptying rate per hour (kABh). Baseline blood samples were taken (0 h), followed by sequential samples at 1, 2, 3, 4, 5, 6, 8, 10, 12, 24, 36, and 48 h relative to initial colostrum feeding. Results for all measurements are presented in the following order, unless otherwise stated: C1, C2, C3, 30-60CR, and 60-90CR. Serum IgG levels at 24 h were different among calves fed C1, C2, C3, 30-60CR, and 60-90CR: 11.8, 24.3, 35.7, 19.9, and 26.9 mg/mL ± 1.02 (mean ± SEM), respectively. Serum IgG at 24 h increased when enriching C1 to 30-60CR, but not from C2 to 60-90CR. Similarly, apparent efficiency of absorption (AEA) values for calves fed C1, C2, C3, 30-60CR, and 60-90CR were different: 42.4, 45.1, 43.2, 36.3, and 33.4% ± 1.93, respectively. Enriching C2 to 60-90CR reduced AEA, and enriching C1 to 30-60CR tended to decrease AEA. The kABh values for C1, C2, C3, 30-60CR, and 60-90CR were also different: 0.16, 0.13, 0.11, 0.09, and 0.09 ± 0.005, respectively. Enriching C1 to 30-60CR or C2 to 60-90CR reduced kABh. However, 30-60CR and 60-90CR have similar kABh compared with a reference colostrum meal (90 g/L IgG, C3). Even though kABh was reduced for 30-60CR, results indicate that C1 has the potential to be enriched and achieve acceptable serum IgG levels at 24 h without affecting AEA.     

双抗体夹心酶联免疫法测定水牛初乳中的IgG

为快速、准确地测定水牛初乳中IgG活性质量浓度,建立了双抗体夹心酶联免疫分析法(ELISA)。结果表明,IgG活性质量浓度的对数值与吸光值存在很好的线性关系,其标准曲线方程式为γ=-0.2907x2+2.0819x+0.8689,相关系数R2=0.9937,线性范围在7.8～1000ng/mL,平均回收率在84.40%～96.71%之间,灵敏度高、重现性好,可用于水牛初乳及其制品中IgG活性质量浓度的检测。     

Effects of lyophilized colostrum and different colostrum feeding regimens on passive transfer of immunoglobulin g in Majorera goat kids

Three experiments were conducted including 180 Majorera kids. In the first experiment, the effect of use of lyophilized colostrum vs. frozen colostrum on immunoglobulin G (IgG) blood serum concentration was evaluated. Kids (n = 40) received the same management and IgG mass [3368 mg/kg of body weight (BW)] during the colostrum feeding period. The IgG in blood serum of kids from the lyophilized colostrum group was greater than that for kids that received frozen colostrum. The second experiment evaluated the effect of total IgG ingested by kids (n = 60) on IgG in blood serum during the colostrum feeding period. Three groups of animals received 3368, 1684, and 842 mg of IgG/kg of BW in 4 feedings for 2 d [high IgG concentration (H-IgG), medium IgG concentration (M-IgG), and low-IgG concentration (L-IgG), respectively]. The IgG blood serum in the kids that received H-IgG was greater than in the other 2 treatment groups, and no statistical differences were found for IgG in blood serum of kids that received either M-IgG or L-IgG. The third experiment evaluated the effect of timing of lyophilized colostrum meals on IgG blood serum concentration. Four groups of kids (n = 80) were used. Two groups received 1684 mg of IgG/kg of BW (higher level-1 d and higher level-2 d) and the other 2 groups received 842 mg of IgG/kg of BW (lower level-1 d and lower level-2 d). Two groups received 2 feedings in 1 d, and the other 2 groups received 4 feedings over a 2-d period, as denoted. Higher level-1 d kids had greater IgG blood serum concentration than the higher level-2 d kids, and no statistical differences were found between lower level-1 d and lower level-2 d kids.     

Influence of pooled colostrum or colostrum replacement on IgG and evaluation of animal plasma in milk replacer

Newborn Holstein (n = 48) and Jersey (n = 30) calves were studied to compare absorption of immunoglobulin G (IgG) from maternal colostrum (n = 39) or colostrum replacement containing an Ig concentrate derived from bovine serum (n = 39). Calves were also fed milk replacer with (n = 38) or without (n = 40) animal plasma (20% of crude protein) to 29 d of age to determine effect of plasma protein on IgG status, health, and growth. Calves were fed maternal colostrum or colostrum replacement at 1.5 and 13.5 h of age and provided a total of 250 or 249 and 180 or 186 g of IgG for Holsteins and Jerseys fed maternal colostrum or colostrum replacement, respectively. Milk replacer (12.5% DM) was fed at 31% of metabolic birth weight (2 feedings/d). Plasma was sampled at 0 h, 24 h, and weekly to determine IgG by turbidimetric immunoassay. At blood collection, calves were weighed and measured to determine growth. Health scores, fecal scores, and grain intake were measured daily. Plasma IgG at 24 h did not differ between calves fed maternal colostrum (13.78 +/- 0.39 g/ L) and colostrum replacement (13.96 +/- 0.38 g/L). Average daily gain, withers height, hip height, body length, heart girth, health, and incidence of diarrhea were not different between treatment groups. Calves fed maternal colostrum used feed more efficiently than calves fed colostrum replacement. Plasma IgG and performance were not affected by the addition of animal plasma to milk replacer. The colostrum replacement used in this study provided adequate IgG for newborn calves. Animal plasma was an acceptable source of protein but did not enhance growth or immunity under the conditions of this study.     

Immunoglobulin G content and colostrum composition of different goat and sheep breeds in Switzerland and Germany

Colostrum represents the sole source to acquire humoral immunity and is an important energy source for newborn lambs and goat kids. However, colostrum composition (i.e., the contents of IgG, fat, protein, and lactose) is affected by various factors such as parity and litter size and, potentially, by breed. In the present study, we examined the colostrum composition of different goat and sheep breeds raised for milk and meat production in Switzerland and Germany. Ten goat breeds (Anglo-Nubian, Appenzell, Boer, Bunte Deutsche Edelziege, Chamois-colored, Grisons Striped, Peacock, Saanen, Toggenburg, and Valais Blackneck) and 10 sheep breeds (Brown-Headed Meat, East Friesian Milk, German Blackheaded Mutton, Gray Horned Heath, Lacaune Dairy, Merino Land, Swiss Black-Brown Mountain, Swiss Charollais, Swiss White Alpine, and Valais Blacknose) were involved in this study. First colostrum samples were obtained from ewes (n = 100) and goats (n = 116) between 10 and 390 min after parturition and analyzed for total IgG, fat, protein, and lactose contents. Colostral IgG concentrations varied between 4.8 and 75.0 mg/mL in goats, and between 6.2 and 65.4 mg/mL in ewes, and the time interval between milking and parturition did not affect colostral IgG concentrations. In goats, the highest IgG concentrations were found in Boer (meat-type; 61.0 ± 10.3 mg/mL; mean ± SD) and the lowest concentrations were observed in Bunte Deutsche Edelziege (milk-type; 26.5 ± 12.5 mg/mL). In sheep, East Friesian Milk and Lacaune Dairy showed the lowest colostral IgG concentrations (17.9 ± 7.3 and 20.2 ± 8.0 mg/mL, respectively), and the highest values were observed in the Merino Land breed (44.2 ± 15.7 mg/mL). The lowest fat and protein concentrations and concomitantly highest lactose concentrations were observed in colostrum of East Friesian Milk and Lacaune Dairy sheep. Parity number did not affect colostrum composition in sheep or goats. In contrast, colostral fat content was higher in ewes bearing twins and triplets than in those carrying singletons. Increasing litter size tended to be associated with higher protein and lower lactose concentrations in ovine (i.e., singletons vs. twins vs. triplets) and caprine colostrum (i.e., singletons vs. twins), whereas colostral IgG concentrations were not affected by litter size. In conclusion, IgG and concentrations of other colostrum constituents showed a wide range in goats and ewes and were mainly affected by the type of breed.     

Short communication: evaluation of a color method for testing immunoglobulin G concentration in goat colostrum

Colostrum samples (n = 1084) of first and second milking from Majorera goats were taken. The immunoglobulin (Ig) G concentrations estimated by measurement of the color of goat colostrum and by the radial immunodiffusion technique were compared. Least squares analysis of the relationship between the color measurement method and IgG concentration resulted in a significant linear relationship. Using 20 mg of IgG/ mL of colostrum as the cut-off point for colostrum selection, the sensitivity, specificity, and negative predictive value of the color method as a test of IgG concentration in goat colostrum were 93.03, 71.43, and 78.12%, respectively.     

牛初乳乳清IgG的低温乙醇和三聚磷酸钠预提取技术研究

探讨了初乳乳清IgG的低温乙醇法和三聚磷酸钠法两种预提取方法。通过正交实验确定了低温乙醇法最佳工艺参数为:乙醇浓度30%、pH6.7、离子强度0.06mol/kg,IgG纯度和回收率分别为39.28%、79.32%;三聚磷酸钠法最佳工艺参数为:三聚磷酸钠添加量0.5%、pH4.0、温度45℃,IgG纯度和回收率分别为33.74%、82.31%。两种方法结合超滤法作为安全有效的预提取法均可应用于工业化生产食品级IgG。      

羊乳酒精稳定性的研究

利用酒精试验对羊乳的酒精稳定性进行了研究,研究结果表明:在pH6.4～7.2时,羊乳酒精稳定性随羊乳pH的升高而增强,羊乳(pH=6.70)中添加44%浓度的等量酒精出现絮状沉淀物,而牛乳通常是添加70%浓度的酒精出珑沉淀;在30～80℃时,羊乳酒精稳定性随着温度的升高而降低;羊乳酒精稳定性随着羊乳中游离Ca2+浓度增大而降低.