牛乳主要过敏原及其检测技术研究进展

牛乳过敏是婴幼儿常见的食物过敏之一,能引发皮肤、胃肠道或者呼吸系统方面的疾病。明确牛乳过敏原的结构及致敏机制,并建立准确且敏感度高的检测分析方法有助于人们预防这类疾病。牛乳中常见的过敏原为酪蛋白、β-乳球蛋白和α-乳白蛋白。本文详述了这些主要过敏原蛋白的结构、致敏机制以及相关的抗体识别序列,并结合国内外关于乳过敏原检测的相关报道,阐述了基于蛋白质和DNA的牛乳过敏原检测技术,包括ELISA、免疫传感器、PCR以及环介导等温扩增技术,以及这些技术应用的优缺点,旨在为牛乳过敏的防控和乳过敏患者的健康提供一定的理论支撑。     

加工对牛乳过敏原的影响

简单介绍了牛乳中主要过敏原成分β-乳球蛋白、酪蛋白、α-乳白蛋白的生化性质及其过敏原表位.详细陈述了加热、加压、酶解、糖基化、发酵等加工方法对牛乳过敏原的影响,对开发无过敏或低过敏的乳制品具有一定指导作用.     

牛乳中主要过敏原组分的分离纯化及鉴定

目的:分离纯化并鉴定牛乳中引起过敏反应的主要致敏组分。方法:采用聚丙烯酰胺凝胶电泳(SDS- PAGE)分析了脱脂乳和乳清的蛋白组分,用饱和硫酸铵分段盐析-DEAE离子交换柱层析纯化过敏原蛋白,脱脂乳和乳清蛋白皮下注射Balb/c小鼠获得高效价特异性IgE抗血清用于免疫印迹分析。结果:免疫印迹分析显示β-乳球蛋白(β-Lg)是引起牛乳过敏的主要过敏原,建立了牛乳过敏小鼠模型。结论:明确了牛乳过敏的主要过敏组分,对牛乳过敏症的诊断治疗以及无过敏原牛乳的制备提供了实验依据。     

牛乳过敏原β-乳球蛋白检测方法的研究进展

目的食物过敏已成为全球性的食品安全问题,欧美等发达国家均要求对食品中的过敏原成分进行标识,其中就包括作为八大过敏性食物之一的牛乳及其乳制品。β-乳球蛋白是牛乳中的主要过敏原,约占乳清蛋白的50%,牛乳总蛋白的10%,并且约有82%的牛乳过敏患者对β-乳球蛋白过敏,因此其可以作为检测食品中是否含牛乳蛋白的一个有效的标志物。建立灵敏、可靠的β-乳球蛋白检测方法,对牛乳过敏原标识及保障牛乳过敏人群的安全消费具有重要意义。本文主要综述了牛乳β-乳球蛋白的高效液相色谱法、超高效液相色谱法、液相色谱-质谱联用法、酶联免疫吸附法、免疫层析法、电化学免疫法、蛋白微阵列法、等离子体共振法等色谱学和免疫学检测方法的研究进展,并对未来发展方向作出展望,以期促进牛乳β-乳球蛋白等过敏原检测方法的研究与开发。     

免疫耐受在牛乳过敏中的研究进展

食物过敏是机体对过敏原产生的一种不良免疫反应,而免疫耐受是指机体对摄入的食物抗原不产生此类免疫应答.近年来,牛乳过敏的发生率越来越高,大部分牛乳过敏的儿童3岁之后出现了免疫耐受.基于此,介绍了牛乳过敏及引发免疫耐受的相关免疫细胞包括树突状细胞、调节性B细胞、调节性T细胞在免疫耐受中的作用及3种诱导免疫耐受的方法.     

牛乳蛋白过敏综述

牛乳蛋白过敏主要发生在牛乳喂养的婴幼儿群体中,它的临床症状主要表现为：频繁胃食管反流、呕吐、非感染（或药物及其它原因）所致的荨麻疹、慢性腹泻、拒食或呕吐引起的生长发育障碍,严重影响了婴幼儿的成长发育。众多研究表明：β-乳球蛋白和α一乳白蛋白是婴幼儿牛乳蛋白过敏的主要过敏原。本文从牛乳蛋白过敏症的发生机理、临床症状、诊断治疗、预防、治疗机理等方面进行综述,以兹为低过敏或抗过敏婴幼儿配方食品开发提供思路,同时对具有过敏风险的婴幼儿提供喂养建议。     

牛乳中主要蛋白过敏原研究现状

牛乳蛋白过敏原的研究成为近几年国内外的研究热点之一.依据有关牛乳中过敏原的研究报道.对牛乳中的主要过敏原酪蛋白、B-乳球蛋白(p-LG)及á一乳白蛋白(á-LA)的结构特征、表位、改性等的研究现状进行介绍,并对牛乳蛋白过敏原的研究进行展望.     

牛乳过敏原及加工技术对其致敏性的影响

对婴幼儿来说,牛乳营养丰富,是母乳最好的替代品,但牛乳中的蛋白质可能会引起过敏。牛乳中的主要过敏原是酪蛋白、β-乳球蛋白和α-乳白蛋白。本文从牛乳过敏原的结构和抗原表位、热处理、发酵和酶处理等不同的加工技术对牛乳蛋白致敏性的影响和过敏原标记检测方法三个方面进行了综述,为开发低致敏牛乳制品提供借鉴。     

非热加工技术在低或无致敏婴幼儿配方粉中应用的研究进展

牛乳营养丰富，对婴幼儿来说，是母乳较好的替代品，绝大多数婴幼儿配方粉都是基于牛乳制备的，非热加工技术在降低牛乳过敏原致敏性，减少营养成分损失等方面表现出较多优势。本文介绍了牛乳中主要过敏原的结构和B细胞表位，总结了低或无致敏婴儿配方粉的研究进展，重点阐述了非热加工技术包括高压、微波、发酵及其与酶解联合处理对乳蛋白致敏性的影响，以及在婴幼儿配方粉中的应用，并对其未来的发展做出了展望，以期能够为营养充足、适口、低或无致敏性新型婴幼儿配方粉的开发提供理论依据。     

乳酸菌降低牛乳中蛋白质致敏性的研究进展

牛乳过敏是一类严重的公共营养卫生问题6为了减少牛乳过敏症的发生率,寻求有效的预防和治疗方法,作者从乳酸菌产蛋白酶水解破坏牛乳过敏原表位和乳酸菌发酵调节免疫系统平衡两方面来阐述乳酸菌的抗过敏机制,并介绍了乳酸菌在预防和治疗过敏性疾病中的潜能及应用前景.     

Milk allergens, their characteristics and their detection in food: A review

Cow's milk allergy (CMA) is one of the most common food allergies in childhood. This allergy is normally outgrown in the first year of life, however 15% of allergic children remain allergic. Many studies have been carried out to define and characterise the allergens involved in CMA and described two major allergens: casein (αs1-CN) and β-lactoglobulin. In addition to this, many other milk proteins are antigenic and capable of inducing immune responses. Milk from sheep or goats differs from cow's milk (CM) in terms of composition and allergenic properties. Food processing such as heating affects the stability, structure and intermolecular interactions of CM proteins, thereby changing the allergenic capacity. Chemical and proteolytic treatments of milk to obtain milk hydrolysates have been developed to reduce allergic reactions. Prevention of CMA largely relies on avoidance of all food products containing cow's milk. To achieve this, interest has focused on the development of various technologies for detecting and measuring the presence of milk allergens in food products by immunoassays or proteomic approaches. This review describes the technologies implemented for the analysis of milk allergens (allergenicity, biochemistry) as well as their potential detection in food matrices.     

牛奶过敏原制备方法的研究和免疫活性鉴别

目的探索牛奶主要过敏原的制备工艺。方法采用等电点沉淀、凝胶层析和分子筛等技术纯化牛奶中主要过敏原组分;采用SDS-PAGE鉴定蛋白纯度,采用双抗原夹心-ELISA鉴定免疫活性。结果成功获得牛奶中的四种主要过敏原组分:酪蛋白、β乳球蛋白、α乳白蛋白和分子量较高的P1组分,并经过免疫实验证实这四种组分均能与过敏血清产生反应,而其中β乳球蛋白和P1组分反应性较高。结论本研究探索出一种简单、实用的牛奶主要过敏原制备工艺,并证实牛奶中的β乳球蛋白和高分子量蛋白质为主要过敏原。     

益生菌改善牛乳蛋白过敏性的研究进展

牛奶蛋白过敏是儿童早期最常见的食物过敏反应之一,通常会持续到成年期。益生菌影响肠道微生物群并调节免疫反应。因此,它可能是可以缓解某些涉及肠道免疫系统疾病的工具,例如尚无治疗方法的牛乳蛋白过敏。本文中探讨了牛奶蛋白过敏的重要研究进展,介绍了牛乳蛋白过敏原和过敏机理。重点强调了益生菌在牛奶蛋白过敏方面取得的最新进展,通过调节肠道菌群和提高肠道免疫来改善牛乳蛋白过敏。最后阐述了低致敏性产品的研究现状,提出了研究及应用中面临的主要问题。益生菌改善牛乳蛋白过敏性的深入研究是过敏领域的重大突破,为缓解牛乳过敏提供理论依据。     

Bovine Milk Allergens: A Comprehensive Review

Cow milk allergy is one of the most common food allergies in early childhood and often persists through adult life, forcing an individual to a complete elimination diet. Milk proteins are present in uncounted food products, such as cheese, yogurt, or bakery item, exposing allergic persons to a constant threat. Many efforts have been made to overcome this global problem and to improve the life quality of allergic individuals. First, proper and reliable food labeling is fundamental for consumers, but the verification of its compliance is also needed, which should rely on accurate and sensitive analytical methods to detect milk allergens in processed foods. At the same time, strategies to reduce milk allergenicity, such as immunotherapy or the use of food processing techniques to modify allergen structure, have to be extensively studied. Recent research findings on the applicability of food processing, such as heat treatment, fermentation, or high pressure, have revealed great potential in reducing milk allergenicity. In this review, significant research advances on cow milk allergy are explored, focusing on prevalence, diagnosis, and therapy. Molecular characterization of cow milk allergens and cross‐reactivity with other nonbovine milk species are described, as well as the effects of processing, food matrix, and digestibility on milk allergenicity. Additionally, analytical methods for the detection of milk allergens in food are described, from immunoassays and mass spectrometry methods for protein analysis to real‐time polymerase chain reaction for DNA analysis.     

Comparative resistance of food proteins to adult and infant in vitro digestion models

IgE‐mediated allergy to milk and egg is widespread in industrialised countries and mainly affects infants and young children. It may be connected to an incomplete digestion of dietary proteins causing an inappropriate immune response in the gut. In order to study this, a biochemical model of infant gastroduodenal digestion has been developed, which has reduced levels of protease (eightfold for pepsin and tenfold for trypsin and chymotrypsin), phosphatidylcholine and bile salts, compared with the adult model. This model has been used to study the behaviour of three characterised food‐relevant proteins (bovine β‐lactoglobulin (β‐Lg), β‐casein (β‐CN) and hen's egg ovalbumin), all of which are relevant cows' milk and hens' egg allergens. Digestion products were characterised using electrophoresis, immunochemical techniques and MS. These showed that ovalbumin and β‐CN were digested more slowly using the infant model compared with the adult conditions. Resistant fragments of β‐CN were found in the infant model, which correspond to previously identified IgE epitopes. Surprisingly, β‐Lg was more extensively degraded in the infant model compared with the adult one. This difference was attributed to the tenfold reduction in phosphatidylcholine concentration in the infant model limiting the protective effect of this phospholipid on β‐Lg digestion.     

质谱技术在食物过敏原检测中的研究进展

食物过敏是当前食品安全领域比较突出的问题,相应的过敏原检测方法研究也越来越受重视。相比于传统的免疫学检测方法,质谱技术在检测加工后以及复杂基质中的食物过敏原中,具有高通量和高灵敏性等优点,被广泛应用于食物过敏原的检测。本文主要从定性和定量2方面介绍了质谱技术在食品过敏原检测中的研究进展。相关研究对牛乳、鸡蛋、小麦和榛子(坚果类)等主要食物过敏原均有涉及。在定性研究中,以肽质量指纹图谱法和肽碎片离子鉴定法为主,鉴定食物中的过敏原蛋白。在定量研究中,通过标记/无标记技术,也能够实现对微量的目标蛋白进行相对/绝对定量。质谱技术应用于食物过敏原检测中,将有助于提升过敏原检测能力,降低食物过敏安全风险。     

A food matrix reduces digestion and absorption of food allergens in vivo

Scope: Food allergy is caused by primary (class 1) food allergens, e.g. Bos d 5 (cow's milk) and Cor a 8 (hazelnut) or secondary (class 2) food allergens, e.g. Mal d 1 (apple). The latter cannot sensitize susceptible individuals but can cause allergy due to immunological cross‐reactivity with homologous respiratory allergens. Here, we studied the effects of food matrix on gastrointestinal proteolysis, epithelial transport and in vivo absorption of class 1 and class 2 food allergens. Methods and results: Mal d 1 lost its IgE‐reactivity immediately after simulated gastric digestion whereas Bos d 5 and Cor a 8 did not. Only Cor a 8 maintained IgE‐binding capacity after simulated intestinal proteolysis. The presence of hazelnut and peanut extracts, which served as protein‐rich model food matrices, delayed gastrointestinal degradation and reduced epithelial transport rates of all allergens through CaCo‐2 monolayers. Finally, IgE‐reactive allergens were assessed at different time points in sera from rats fed with all three allergens with or without hazelnut extract. The levels of all allergens peaked 2 h after animals were fed without matrix and increased over 8 h after feeding. Conclusions: A protein‐rich food matrix delays gastrointestinal digestion and epithelial transport of food allergens and thereby may affect their sensitizing capacity and clinical symptoms.     

食品过敏原标签要求及生产过程控制初探

食品过敏已成为世界关注的重大公共卫生学和食品安全问题。食品过敏原是引起食品过敏的直接诱因,具有耐加工和交叉反应的特性。国际食品法典委员会(Codex Alimentarius Commission,CAC)规定了必须在食品标签中标注的8种可能引起过敏反应的食品及其配料,包括含有麸质的谷类、甲壳动物及其制品、鸡蛋及其制品、鱼类及其制品、花生、大豆及其制品、奶和奶制品(包括乳糖)、坚果及其制品、浓度不低于10 mg/kg的亚硫酸盐。欧盟、美国、日本、澳大利亚和新西兰等已根据国际食品法典委员会对过敏原的要求出台强制性标识食品过敏原的法规,这在一定程度上对我国出口食品企业造成了影响。本文通过对比CAC以及欧盟、中国、美国、日本、澳大利亚和新西兰等地有关过敏原标签的要求,提醒出口食品加工企业减少因标签不合格造成的经济损失,并为其在生产加工过程中过敏原的控制提出建议。