致乳糜泻小麦麸质检测方法研究进展

乳糜泻是因遗传易感者对麸质不耐受而引发的肠道疾病,该病是终生的且极少量麸质的摄入就会导致患病。因此,对食物中麸质的检测和定量显得尤为重要。目前,用于检测麸质的方法主要有ELISA法、免疫印迹法、质谱法和PCR法。本文将详细叙述这四种方法在检测麸质上的应用及其优缺点。其中,ELISA法在麸质的快速检测上使用较多;免疫印迹法检测结果稳定直观,但定量精确度不高;质谱法准确度非常高,但费时费力,且依赖贵重设备;PCR法在检测食物基质复杂、麸质含量低的食品上具有优势。      

小麦麸质蛋白相关性疾病的研究进展

小麦是主要的粮食作物,但也可引发多种过敏性疾病和自身免疫性疾病。麸质蛋白的摄入,是引起这些疾病的关键因素,麸质蛋白主要存在于小麦中,但也存在于大麦,黑麦和燕麦中。特别是小麦麸质蛋白因含有大量的非极性氨基酸和谷氨酰胺而耐胃肠道酶消化,生成使部分人群致病的毒性肽。麸质蛋白相关性疾病的全球患病率接近5%,已经严重影响了部分人群的生活质量,甚至危及生命,已成为全球性不可回避的食品安全问题之一。本文主要对麸质蛋白结构、麸质蛋白相关性疾病的发病机制、流行病学、诊断和治疗进行了概述,为小麦的安全食用提供参考。     

小麦麸质蛋白中乳糜泻关联表位的检测方法研究进展

乳糜泻关联表位的定量检测可以评价小麦种质资源及加工食品的乳糜泻致敏性,为患者安全消费提供技术保障。定量检测小麦麸质蛋白中致乳糜泻表位的方法包括免疫印迹法、高通量测序法和多反应检测串联质谱检测（LC-MRM/MS）,它们在麸质表位的检测中各具特色。免疫印迹法检测结果稳定直观,但定量精确度不高;高通量测序法准确度相对较高,但应用范围窄,且数据处理困难;多反应检测串联质谱检测灵敏度高、样品用量少、分析速度快,但费用较高。      

水溶性小麦蛋白制备工艺研究

水溶性小麦蛋白系以谷朊粉为原料,经复水、预处理、酶水解和干燥所得产品。加酶量为1350U/g干物质,反应温度55℃;所得产品蛋白质含量为75.1%,氮溶解指数(NSI)为95.5%,乳化能力(EC)为1.2,乳化稳定性(ES)为84.6%。     

Gluten contamination of naturally gluten-free flours and starches used by Canadians with celiac disease

A large national investigation into the extent of gluten cross-contamination of naturally gluten-free ingredients (flours and starches) sold in Canada was performed. Samples (n = 640) were purchased from eight Canadian cities and via the internet during the period 2010–2012 and analysed for gluten contamination. The results showed that 61 of the 640 (9.5%) samples were contaminated above the Codex-recommended maximum level for gluten-free products (20 mg kg^–1) with a range of 5–7995 mg kg^–1. For the ingredients that were labelled gluten-free the contamination range (5–141 mg kg^–1) and number of samples were lower (3 of 268). This picture was consistent over time, with approximately the same percentage of samples above 20 mg kg^–1 in both the initial set and the subsequent lot. Looking at the total mean (composite) contamination for specific ingredients the largest and most consistent contaminations come from higher fibre ingredients such as soy (902 mg kg^–1), millet (272 mg kg^–1) and buckwheat (153 mg kg^–1). Of the naturally gluten-free flours and starches tested that do not contain a gluten-free label, the higher fibre ingredients would constitute the greatest probability of being contaminated with gluten above 20 mg kg^–1.     

Gluten contamination in oat products and products naturally free from gluten

Some countries now allow celiac patients to include oats in their gluten-free diet. Studies have shown that commercially available oats can be contaminated with gluten. The aim of the study was to analyse oat products and products naturally free from gluten to determine the degree of contamination. A total of 88 oat products and 22 products based on maize, rice, millet or buckwheat were analysed, using a commercially available enzyme-linked immunosorbent assay (ELISA) with a monoclonal antibody to gliadin. The ELISA is quantitative with a detection limit of 20 mg/kg gluten. Some of the positive samples were also analysed for the presence of DNA from wheat, barley or rye. Thirteen percent of the oat products had gluten content over 200 mg/kg. Of the products naturally free from gluten 14% had a gluten content over 200 mg/kg. There was a tendency for higher levels of contamination with increased processing. The risk of gluten contamination in oat products as well as in non-gluten cereals must be considered. The level of contamination was in most cases low. The results regarding oats can be compared to those of such cereals as maize, rice, buckwheat and millet.     

Non‐Celiac Gluten Sensitivity: How Its Gut Immune Activation and Potential Dietary Management Differ from Celiac Disease

Non‐celiac gluten sensitivity (NCGS) is a clinical entity triggered by the ingestion of gluten‐containing grains leading to intestinal and/or extraintestinal symptoms that resolve once the gluten‐containing foodstuff is eliminated from the diet, and it is diagnosed when celiac disease (CD) and wheat allergy (WA) have been ruled out. The limited knowledge about the pathophysiology of NCGS and the lack of validated biomarkers are still major limitations for clinical studies, making it difficult to differentiate NCGS from other gluten‐related disorders (GRD). In the absence of clear‐cut diagnostic criteria, NCGS is still mainly a diagnosis of exclusion. Several studies suggest that NCGS is an immune‐mediated disease that likely activates an innate immune response. Moreover, it has recently been hypothesized that in addition to gluten, other components of wheat may be responsible for the symptoms observed in individuals without CD. This review aims at discussing available evidence related to the histological and immunological features in the gut mucosa of patients with NCGS and at outlining new dietary opportunities for these patients.     

以麸质蛋白为靶向的乳糜泻治疗方法研究进展

乳糜泻(celiac disease,CD)是携带遗传易感基因人群的自身免疫疾病,其特点是摄入含麸质蛋白的小麦或大麦和黑麦产品后,小肠会受到炎症性损伤。乳糜泻患者必须终生坚持无麸质饮食,这是目前唯一有效的治疗方法。然而,严格遵守无麸质饮食是困难的,需要新的治疗方法来补充甚至替代饮食治疗。尽管迄今为止,还没有技术允许乳糜泻患者无限制地安全食用含麸质的产品,但随着对乳糜泻发病机制认识的不断深入,在无麸质饮食替代疗法方面已经取得了有希望的进展。本文综述了以麸质蛋白为靶向的乳糜泻治疗方法研究进展,如下调麦醇溶蛋白的表达、麦醇溶蛋白的隔离、谷氨酰胺残基的转酰胺化和免疫显性肽的酶解,批判性地讨论了这些治疗方法的实用性和获得的结果。     

Physiopathology and Management of Gluten‐Induced Celiac Disease

Proline‐ and glutamine‐rich gluten proteins are one of the major constituents of cereal dietary proteins, which are largely resistant to complete cleavage by the human gastrointestinal (GI) digestive enzymes. Partial digestion of gluten generates approximately 35 amino acids (aa) immunomodulatory peptides which activate T‐cell–mediated immune system, followed by immunological inflammation of mucosa leading to the onset of celiac disease (CD). CD is an autoimmune disease associated with HLA–DQ2/DQ8 polymorphism and dysbiosis of gut microbiota. CD is either diagnosed using duodenal mucosal biopsis or serological testing for transglutaminase 2 (TG2) specific antibodies (IgA and IgG). Current therapy for CD management is gluten‐free diet, while other therapies like glutenase, probiotics, immunomodulation, jamming of HLA‐DQ2, inhibition of TG2, and gluten tolerance aided by gluten tolerizing vaccines are being developed.     

谷朊粉的研究与应用

谷朊粉由于其黏弹性、乳化性等特性,在食品工业和饲料工业等领域有着广泛的应用。介绍了谷朊粉的组成、特性以及近年来的研究与应用情况。     

小麦面筋蛋白结构及其改性研究

小麦面筋蛋白是生产小麦淀粉时副产品,具有价格低廉、产量大等特点。小麦面筋蛋白因分子量大、结构复杂、溶解性低而使其应用受限,因此在认识小麦面筋蛋白结构基础上,研究其结构及性能方面改性方法,对拓宽小麦面筋蛋白应用和缓解小麦过饱和问题都大有裨益。     

面筋蛋白的组成、分离方法及应用研究进展

小麦面筋蛋白是一种营养丰富、物美价廉的植物性蛋白,主要包含清蛋白、球蛋白、麦谷蛋白和醇溶蛋白,可以面粉为原料也可采用整粒小麦直接湿磨法得到。本文对小麦面筋蛋白在食品、化工及饲料等行业中的应用进行了详细的综述,并对小麦面筋蛋白未来的研究趋势进行了展望。      

谷朊粉应用及深加工技术研究进展

在介绍谷朊粉应用现状的基础上,对酶解谷朊粉以及发酵谷朊粉的研究进展进行了综述,并探讨了谷朊粉研究开发中存在的问题,以期为谷朊粉的深度加工提供一定的参考。     

小麦面筋蛋白组成、结构和功能特性

小麦面筋蛋白(俗称谷朊粉)主要由麦醇溶蛋白和麦谷蛋白组成,其蛋白组成和结构是影响小麦面团特性和烘焙品质重要因素。该文对小麦面筋蛋白组成、结构进行综述,以更清楚了解其结构对功能性影响。     

谷朊粉改性研究进展

谷朊粉是一种营养丰富的植物蛋白资源,其特有功能性质在食品生产中具有广泛用途.通过一定生物化学手段改性,可大大拓宽谷朊粉应用范围.主要综述近年来有关谷朊粉物理、化学、酶法和基因工程改性方面的研究进展.     

一种基于BALB/c背景由膳食麸质引起的乳糜泻小鼠模型的构建及其评价

目的：利用麸质诱导建立小鼠乳糜泻（celiac disease,CeD）模型,通过检测乳糜泻相关指标来评价该模型的可行性。方法：将连续食用无麸质饲料3 代以上的雌性BALB/c小鼠（6～8 周龄）随机分为两组（对照组（Control组）和模型组（CeD组））,CeD组于实验开始的第1天将饲料换为麸质含量2.5 g/kg的含麸质饲料,Control组则继续饲喂无麸质饲料。实验前3 周,分别给予CeD组每只小鼠腹腔注射含150 μg麦醇溶蛋白的磷酸盐缓冲溶液（0.2 mL 0.01 mol/L）,每周两次。在实验的第4周,给予CeD组每只小鼠后脚掌注射乳化有50 μg麦醇溶蛋白的弗氏完全佐剂50 μL两次（第1天和第4天各注射一次）。利用血清荧光素异硫氰酸酯-葡聚糖质量浓度表征小鼠的肠道通透性;利用实时荧光定量聚合酶链式反应检测小鼠十二指肠组织中紧密连接蛋白（ZO-1、ZO-2、Claudin-1等）、相关炎症因子白细胞介素（（interleukin,IL）-15、干扰素（interferon,IFN）γ和IL-4等）和相关免疫细胞的表面标志物基因（CD4、CD19、CD138等）的表达水平;采用酶联免疫吸附试验测定小鼠十二指肠中组织转谷氨酰胺酶（tissue transglutaminase,tTG）和连接蛋白水平。结果：相比Control组,CeD组小鼠十二指肠肠道屏障被明显破坏,小肠绒毛长度明显缩短,TGM2 mRNA相对表达量显著升高（P＜0.05）,与乳糜泻相关的炎症因子和免疫细胞的标志物基因相对表达量都显著升高。结论：该造模方法在肠道病理情况、肠道屏障以及免疫方面均能很好地模拟临床上乳糜泻的病理学特征,可用于未来乳糜泻新的潜在治疗措施研究中。     

Inhibitory activity towards human α‐amylase in wheat flour and gluten

Wheat α‐amylase inhibitors (AI) have been targeted as potential triggers of noncoeliac gluten or wheat sensitivity (NCGS). The aim of this study was to determine AI activity towards α‐amylase from human source in wheat cultivars. Contrary to barley, buckwheat, or oats, high level of AI activity was found in wheat and, to a lesser extent, rye. AI activity (mean IC₅₀ = 137 μg mL^?1) did not vary with respect to ancient or recently developed wheat cultivars. Vital wheat gluten had very high and heat‐stable AI activity (mean IC₅₀ = 23 μg mL^?1), higher than wheat starch (?10 000 μg mL^?1) or acarbose (40 μg mL^?1), a medication for the management of hyperglycaemia and potentially causing digestive disorders due to the accumulation of undigested carbohydrates in the intestine. Data suggest that eating raw wheat gluten, flour or dough could pose a health risk.     

面筋中腐败微生物的分离和鉴定的研究

该实验对变质面筋中腐败微生物进行分离,分离出的18株微生物全部为细菌,并对其进行面筋腐败验证试验,所有菌株均能在24 h内引起面筋变质。对面筋中腐败微生物进行分离纯化以及生理生化试验,初步鉴定引起面筋变质的腐败微生物主要为地衣芽孢杆菌（Bacillus licheniformis）,枯草芽孢杆菌（Bacillus subtilis）,巨大芽孢杆菌（Bacillus megaterium）以及蕈状芽孢杆菌（Bacillus mycoides）。     

小麦面筋蛋白酶解物对小鼠溃疡性结肠炎的影响

以小麦面筋蛋白为原料,采用定向酶解工艺制备富含Gln的小麦面筋蛋白酶解物,并通过葡聚糖硫酸钠(DSS)诱导的小鼠结肠炎模型,探讨酶解物对小鼠溃疡性结肠炎的调节作用。结果表明:小麦面筋蛋白酶解物能缓解DSS诱导的结肠炎小鼠体重降低和炎症临床症状,提高小鼠结肠组织的抗氧化能力,减轻结肠组织炎症因子分泌和炎症细胞的浸润。表明小麦面筋蛋白酶解物能有效缓解溃疡性结肠炎小鼠的肠道炎症。     

谷朊粉改性技术研究进展

综述了谷朊粉的物理、化学、酶法等改性技术的研究进展及对其乳化性的影响.