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大豆营养丰富,但其抗原蛋白的高致敏性易导致严重过敏反应。大豆球蛋白和β-伴球蛋白是大豆的主要过敏原,其抗原表位对致敏性起决定作用。通过适宜的加工手段改变过敏原蛋白表位结构,从而影响致敏性。糖基化是当前最有前景实现工业化的非酶加工新技术,不仅能改变蛋白质的结构、营养特性,同时能降低致敏性。文章介绍了大豆主要抗原蛋白的结构、糖基化反应,重点总结了大豆糖基化抗原蛋白致敏性的变化及其对肠道健康的影响,同时对糖基化蛋白面临的挑战进行展望,旨在为糖基化蛋白低致敏性产品的开发及促进肠道健康提供参考。 相似文献
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本研究对我国国产与进口乳制品的致敏原标识现状进行分析,同时对比我国和国外食品致敏原标签法规,针对我国致敏原标签管理中的问题提出相关建议。通过对比我国国产与进口乳制品产品的致敏原标识情况发现,国产与进口产品的致敏原标识率均较低;在致敏原的标识位置、标识用语以及标识内容强调方面,国产与进口乳制品均存在不足,其中致敏原标识位置在配料表下方的国产与进口乳制品分别占60.0%和55.6%;在致敏原标识用语方面,国外品牌更偏向使用"过敏"或"致敏"为引导词;在致敏原标识内容的强调方面,国内外只有2 个品牌通过字体加粗或改变字体颜色的方式对致敏原进行了强调。 相似文献
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牛乳过敏是一种较严重的食源性疾病,通常因为乳中蛋白质和其代谢产物之间发生交互作用而导致人体出现免疫功能紊乱。目前已有研究证明,牛乳过敏逐渐成为全球性的重大公共卫生问题,尤其是在婴幼儿阶段。本文详细阐述酪蛋白、α-乳白蛋白和β-乳球蛋白的过敏发生机理,介绍目前成功应用于检测牛乳过敏成分的技术并探讨其在实际应用中的不足,列举国内外研究人员利用改性技术研发出的一些低致敏性乳制品,并展望乳过敏原改性的发展方向和低致敏性乳制品的广阔市场前景,为低致敏性乳制品的发展提供一定的理论依据和研究思路。 相似文献
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大豆蛋白质含量达 37% ,含油脂 1 8% ,可以最大限度地满足鸡对蛋白质和能量的需求。然而大豆中含有多种抗营养因子 (ANFs) ,如蛋白酶抑制因子 (TI)、植物凝集素 (PHA)、皂角苷、致甲状腺肿因子、致佝偻病因子、致敏因子和金属螯合因子等 ,这些ANFs对鸡产生不同程度的影响 ,其中胰蛋白酶抑制因子和植物凝集素的影响最大。1 抗营养因子的种类和特点抗营养因子最新定义 :一些对人和动物生长、健康有不良影响的非纤维性天然物质 (Huismaan和Jansman ,1 991 )。主要包括TI、PHA、皂角苷、致甲状腺肿因子、致敏… 相似文献
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酶联免疫法测定大豆11S抗原蛋白 总被引:3,自引:0,他引:3
豆粕的蛋白质含量高达40%~55%,含有人体所必需的8种氨基酸,为全价蛋白源.豆粕蛋白质的赖氨酸含量丰富,还含有较多的天门冬氨酸、谷氨酸,是单胃动物良好的日粮蛋白源.目前豆粕已是畜牧饲养业和水产养殖业最重要的配合饲料原料,占蛋白饲料的80%~90%.虽然豆粕中蛋白质含量丰富,但生豆粕中含有多种抗营养因子(antinutritional factors,ANF),主要包括大豆抗原蛋白(致敏因子)、胰蛋白酶抑制剂、植酸、大豆凝血素、脲酶、低聚糖、脂肪氧化酶及致甲状腺肿素等,这些抗营养因子阻碍营养成分的消化、吸收和利用,并对动物的生长发育和健康造成不良影响. 相似文献
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大豆抗原蛋白的研究进展 总被引:4,自引:0,他引:4
大豆蛋白是应用最广泛的植物饲料蛋白质资源,其蛋白质含量高,除富含蛋氨酸外,其他氨基酸也较平衡,但是由于大豆中存在一些抗营养因子如抗胰蛋白酶因子、抗原蛋白和低聚糖,从而限制了其在早期断奶仔猪和犊牛日粮中的应用。抗原蛋白是饲料中的大分子蛋白质或糖蛋白,会降低体液反应,又称为致敏因子。目前研究证实大豆所含的球蛋白和β-伴球蛋白是引起仔猪和犊牛过敏反应的主要物质。1大豆抗原蛋白的抗营养作用大豆抗原蛋白的抗营养作用主要有:1)降低饲料蛋白质的利用率;2)由于活化免疫系统而提高了维持需要;3)增加内源蛋白质的分泌,导致粪氮增… 相似文献
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豆粕中抗营养因子处理技术研究进展 总被引:3,自引:0,他引:3
豆粕中的蛋白质含量高,营养成分比较齐全且平衡,是单胃动物很好的日粮蛋白源。但是,豆粕中还存在胰蛋白酶抑制剂、大豆凝血素、大豆抗原蛋白(致敏因子)、脲酶、低聚糖、脂肪氧化酶、植酸及致甲状腺肿素等多种抗营养因子。它们 相似文献
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魏静 《四川畜牧兽医学院学报》2009,(4):28-32
在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。 相似文献
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本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。 相似文献
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以国际标准强毒R株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离MG,并收集感染鸡所产蛋分离MG。结果表明,人工感染48小时后上、下呼吸道及肺已被全面感染,96小时气囊已被感染,120小时输卵管已能分离到MG,卵巢始终分离不到MG。人工感染鸡自144小时便能在其所产蛋中分离出MG。药物治疗能在72小时内消除感染,油乳剂苗则需24天后逐渐降低蛋内MG分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内MG,但以研制的种蛋浸泡剂药浴效果为最好。 相似文献
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REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air. 相似文献
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Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF
Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo. 相似文献