母乳低聚糖与婴幼儿健康关系研究进展

母乳低聚糖在促进婴幼儿生长发育上发挥重要作用,目前已报道的母乳低聚糖超过200种。文章综述了母乳低聚糖的种类与结构、对婴幼儿肠道健康的影响、免疫调节作用及促进大脑发育等相关研究成果,总结了母乳低聚糖的应用现状,展望了未来母乳低聚糖工业化生产及其应用的可能性和必要性。     

母乳低聚糖的结构与功能研究进展

母乳低聚糖(human milk oligosaccharides, HMOs)是人乳中仅次于乳糖和脂肪的第三大营养物质,是母乳的独特成分,在婴幼儿生长发育中起到重要作用。每种母乳低聚糖可能具有不同的功能。本文阐述了母乳低聚糖结构组成、功能作用机理以及应用现状,为婴幼儿配方食品的设计、开发提供理论支持。     

母乳源乳酸菌的低聚糖利用特性研究

为探究母乳源乳酸菌对不同低聚糖的利用特性,比较了8株不同种属的乳酸菌在6种低聚糖及复配低聚糖培养基中的生长能力。结果表明,低聚果糖和菊粉对4株副干酪乳杆菌均具有促生长作用(生长量大于葡萄糖);低聚果糖和低聚半乳糖能明显促进植物乳杆菌M113的增长;鼠李糖乳杆菌M53对低聚半乳糖的利用情况优于其他低聚糖;2株双歧杆菌对低聚半乳糖和水苏糖的利用较强。所测母乳源乳酸菌均不能较好利用低聚木糖人乳中常见的2′-岩藻糖基乳糖。8株母乳来源的乳酸菌对低聚糖的利用具有菌株特异性。菌株在混合低聚糖中的生长能力取决于其偏爱低聚糖的含量。该实验结果能够为婴幼儿配方奶粉中益生菌和低聚糖的筛选提供数据支持。     

低聚果糖与婴幼儿健康关系的研究进展

母乳中的低聚糖对婴幼儿健康发挥重要作用。低聚果糖(FOS)是常用来模拟母乳中低聚糖的配方奶粉添加剂之一,可能有助于婴幼儿改善肠道菌群、调节肠道功能、预防过敏及促进矿物质吸收。本文对FOS结构功能以及与婴幼儿健康的关系进行综述,为FOS在婴幼儿营养方面的合理应用提供科学依据。     

母乳低聚糖的研究进展

母乳低聚糖(human milk oligosaccharides,HMOs)是人乳中仅次于乳糖和脂肪的第三大营养物质,是母乳的独特成分,影响着婴儿的生长发育。每个HMO可能具有不同的功能。母乳低聚糖可作为益生元影响肠道微生物群的组成;亦可以充当抗黏附剂或受体诱饵阻止病毒、细菌等病原体与上皮细胞表面的糖结合;还可以作为免疫调节剂改变宿主上皮细胞和免疫细胞应答,对健康有潜在益处。全面阐述低聚糖结构与功能的关系,在原则上需要获得所有HMO的信息,这促进了合成HMO方法的发展。这些方法还在进一步完善,以满足工业生产食品添加剂的经济要求,同时,人们也在为建立具有不同链长、分支模式和岩藻糖基化或唾液酸化低聚糖的HMO库而不懈努力。     

母乳低聚糖的研究进展

母乳中母乳低聚糖(HMOs)含量丰富且独特,在已知的200种成分中,有157种结构被阐明。HMOs不仅具有"双歧因子"效果,还具有抗黏附、抗菌、调节肠道上皮细胞和免疫细胞,减少过度的黏膜白细胞浸润和活化,降低新生儿坏死性小肠结肠炎等功效,并为婴幼儿大脑发育和认知提供唾液酸作为潜在的必要营养素。由于HMOs大规模生产受限,因此化学和生物模拟的HMOs代替品不断出现。虽然经典的代替品,如低聚半乳糖和低聚果糖具有HMOs部分功效,但是其结构组成差异明显,部分国家批准上市的2'-岩藻糖基乳糖(2'-FL)和乳糖-N-新四糖(LNnT)只是模拟了HMOs中一种或几种分子结构。富集牛乳低聚糖作为HMOs替代品具有明显优势。本文综述母乳低聚糖不同泌乳期含量、分型、结构特征、分析方法、生理功能、消化吸收和模拟,介绍牛乳低聚糖产业化模拟母乳低聚糖的可能性,旨在为HMOs替代品的研究、开发与产业化提供理论参考。     

阿魏酰低聚糖制备、结构及生物活性研究进展

对阿魏酰低聚糖的结构,抗氧化、抗糖化、促进益生菌增殖等生物活性,应用以及阿魏酰低聚糖的提取、分离纯化、分析检测方法予以综述,指出当前阿魏酰低聚糖研究出现的问题,并对其研究前景进行展望,以期为阿魏酰低聚糖的深入研究和开发利用提供理论依据。     

低聚糖阿魏酸酯含量的快速测定方法

分别以麦麸、玉米芯、玉米麸皮为原料,采用酶法制备低聚糖阿魏酸酯,探讨其快速检测方法,并通过高效液相色谱法验证该法的准确性。结果表明,采用Amberlite 树脂分离纯化可除去样品中的低聚糖(不含结合态的阿魏酸)、双波长分光光度法(345nm 和375nm)结合还原糖法可用于对低聚糖阿魏酸酯进行准确定量。     

母乳低聚糖与婴儿肠道菌群相关性研究进展

母乳中含有丰富的母乳低聚糖（human milk oligosaccharides,HMOs）,可以刺激新生儿肠道中有益细菌的生长从而起到益生元的作用。目前我国允许添加到婴幼儿配方奶粉中的低聚糖在结构上与HMOs不同,因此,它们无法模拟HMOs的某些结构特异性效应。本文综述了HMOs的组成、结构以及在母乳中的含量,重点阐述了HMOs及其代谢产物与婴儿肠道微生物群间的关系,最后探讨了HMOs配方奶粉喂养对婴儿肠道菌群产生的有益作用,为推进HMOs在婴幼儿配方食品中的应用提供理论支持。     

高效液相色谱法测定母乳及牛乳中总核苷酸含量

建立高效液相色谱测定母乳和牛乳中总核苷酸含量和组成的分析方法。总核苷酸包括游离核苷酸、游离核苷、核苷聚合物及加合物等不同来源的可利用核苷总量。利用酶解法释放出母乳中的核苷,以硼化聚丙烯酰胺凝胶（Affi-Gel 601）作为固相萃取介质进行样品净化,用反相高效液相色谱仪检测,内标法定量,检测结果以核苷酸计。且针对母乳样品的特性,增加高温灭活步骤进行样品前处理,以检测母乳中核苷酸的天然含量及组成。对所建方法进行全面验证,结果表明其具有良好的线性,相关系数（r2）均在0.999以上;母乳中各核苷酸的检出限和定量限分别在0.18～0.45 mg/L和0.60～1.51 mg/L之间;母乳基质中3 种不同加标水平下总核苷酸的回收率均在99%～108%之间,连续3 d 6 次检测结果的相对标准偏差在0.8%～7.8%之间,显示了良好的准确性及精密度。然后进一步利用所建检测方法,评估母乳及5 种市面常见的牛乳中的核苷酸总量及组成用以验证该方法的适用性。该方法的灵敏度、准确性及精密度均可满足对母乳和牛乳样品中天然的核苷酸含量及组成的测定要求。本研究为今后大样本量调查母乳及牛乳样品中核苷酸的含量和组成提供了更加科学准确的方法。     

Applications of Raman spectroscopic techniques for quality and safety evaluation of milk: A review of recent developments

Milk is a complete nutrient source for humans. The quality and safety of milk are critical for both producers and consumers, thereby the dairy industry requires rapid and nondestructive methods to ensure milk quality and safety. However, conventional methods are time-consuming and laborious, and require complicated preparation procedures. Therefore, the exploration of new milk analytical methods is essential. This current review introduces the principles of Raman spectroscopy and presents recent advances since 2012 of Raman spectroscopic techniques mainly involving surface-enhanced Raman spectroscopy (SERS), fourier-transform (FT) Raman spectroscopy, near-infrared (NIR) Raman spectroscopy, and micro-Raman spectroscopy for milk analysis including milk compositions, microorganisms and antibiotic residues in milk, as well as milk adulterants. Additionally, some challenges and future outlooks are proposed. The current review shows that Raman spectroscopic techniques have the promising potential for providing rapid and nondestructive detection of milk parameters. However, the application of Raman spectroscopy on milk analysis is not common yet since some limitations of Raman spectroscopy need to be overcome before making it a routine tool for the dairy industry.     

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.     

Accurate analysis of residual lactose in low-lactose milk: Comparing a variety of analytical techniques

To receive the designation “lactose-free”, milk should contain <0.01% (w/w) lactose. As the analysis of such low levels of lactose is often hampered by other saccharides present or formed during milk processing, methods are required that are highly sensitive, accurate and precise. Currently, there is no international standard analysis method for the determination of lactose in low- or lactose-free milk, despite such a need from the dairy industry. We validated the analysis of residual lactose in lactase-treated UHT milk using HPAEC-PAD on a CarboPac PA100 column and compared it with a variety of commonly used analytical techniques for measuring lactose, including HPLC-RI, NMR, enzymatic kits, cryoscopy, and lactose biosensors. The results show that only one analytical technique, namely the Biomilk³⁰⁰, an amperometric biosensor, has performance comparable with analysis by HPAEC-PAD, which remains one of the most accurate, precise and sensitive methods to assess low levels of lactose in milk.     

Determination of bisphenol A in milk and dairy products by high-performance liquid chromatography with fluorescence detection

This study was conducted to develop a selective and sensitive method for the determination of bisphenol A (BPA) levels in milk and dairy products. A method based on solvent extraction with acetonitrile and solid-phase extraction (SPE) was developed for the analysis of BPA in milk, yogurt, cream, butter, pudding, condensed milk, and flavored milk, and a method using two SPE cartridges (OASIS HLB and Florisil cartridge) for skim milk was also developed. The developed methods showed good recovery levels (77 to 102%) together with low detection limits (1 microg/liter for milk, yogurt, pudding, condensed milk, flavored milk, and skim milk and 3 microg/liter for cream and butter). These methods are simple, sensitive, and suitable for the analysis of BPA in milk and dairy products. When 40 milk and dairy products were analyzed by the proposed methods, BPA was not identified in noncanned products, but its levels ranged from 21 to 43 microg/kg in canned products, levels that were 60- to 140-fold lower than the migration limits in the European Union and Japan.     

Multiclass methods for the analysis of antibiotic residues in milk by liquid chromatography coupled to mass spectrometry: A review

Milk is an important and beneficial food from a nutritional point of view, being an indispensable source of high quality proteins. Furthermore, it is a raw material for many dairy products, such as yoghurt, cheese, cream etc. Before reaching consumers, milk goes through production, processing and circulation. Each step involves potentially unsafe factors, such as chemical contamination that can affect milk quality. Antibiotics are widely used in veterinary medicine for dry cow therapy and mastitis treatment in lactating cows, which can cause the presence of antimicrobial residues in milk. In order to ensure consumers’ safety, milk is analyzed to make sure that the fixed Maximum Residue Limits (MRLs) for antibiotics are not exceeded. Multiclass methods can monitor more drug classes through a single analysis, so they are faster, less time-consuming and cheaper than traditional methods (single-class); this aspect is particularly important for milk, which is a highly perishable food. Nevertheless, multiclass methods for veterinary drug residues in foodstuffs are real analytical challenges. This article reviews the major multiclass methods published for the determination of antibiotic residues in milk by liquid chromatography coupled to mass spectrometry, with a special focus on sample preparation approaches.     

奶茶粉脂肪酸指纹特征及真实性判别模型建立

目的 评价以脂肪酸(fatty acid, FAs)指纹建立奶茶粉真实性判别模型的可行性。方法 采集生牛乳喷雾干燥(湿法)和植脂末、乳粉、炼乳粉粉末原料混合制备(干法)奶茶粉138种产品,并采集植脂末、奶油粉和奶粉为参照样品,气相色谱法检测FAs,进行差异性比较,并进行正交偏最小二乘判别分析(orthogonalpartial least squares discriminant analysis, OPLS-DA)和层聚类分析(hierarchical cluster analysis,HCA),观察各种类奶茶粉样品聚类特征,评价模式相似度。构建奶茶粉掺植脂末OPLS-DA和偏最小二乘(partial least square, PLS)预测模型。结果 生牛乳湿法制备的奶茶粉与其他3种干法制备的奶茶粉FAs指纹显著不同,与奶粉有同质性,两者模式相似度为94.9%; 3种干法制备的奶茶粉与植脂末、奶油粉存在同质性,可归入同一个大类,模式相似度为27.2%。OPLS-DA和PLS模型有良好的预测能力,可以区分0%植脂末(奶粉)与添加12.5%植脂末的人工奶茶粉样品。3种市售干法制备奶茶粉...     

牛奶脂肪酸检测方法的研究进展

牛奶脂肪酸组成不仅与其理化性质和营养品质密切相关,还是评价奶牛健康状况的重要指标。建立准确的定性定量方法,能够全面地了解牛奶脂肪酸组成,有利于奶牛场对奶牛的饲养管理和乳品加工厂对乳制品的质量控制。本文针对牛奶脂肪酸分析中的样品前处理技术和仪器检测技术进行了综述,旨在对比不同检测方法的优缺点,为建立牛奶脂肪酸高通量、高灵敏度的分析方法提供参考。     

Development of a rapid mitochondrial DNA extraction method for species identification in milk and milk products

Isolation of mitochondrial DNA (mtDNA) from milk offers an effective way to monitor aspects of quality control and traceability to ensure food safety. A few methods of DNA isolation from milk have been reported, but many of them are time consuming and expensive. Here, we report a rapid, simple, and efficient method of mtDNA extraction from raw and processed milk (pasteurized, retorted, and UHT milk) to generate substrate for analysis using any PCR analysis platform. Various techniques used for the separation of mitochondria were explored and combined with a sodium dodecyl sulfate method for mtDNA extraction from raw and processed milk. The optimized protocol supports the efficient amplification of mtDNA independent of sample origin and is sufficiently straightforward to allow its widespread adoption by industry.     

基于Heracles Ⅱ超快速气相电子鼻对不同加工方式牛奶的快速鉴别

利用Heracles II超快速气相电子鼻对不同加工方式牛奶中的挥发性有机化合物进行检测。采用主成分分析、样品间区别指数分析和主成分载荷图分析对不同加工方式牛奶挥发性物质的差异性进行比较,结果表明奶粉的整体风味与其他三种不同加工方式样品差异较大,而超巴氏奶与超高温灭菌奶差异较小。结合保留指数和Aro Chem Base数据库对特异性化合物进行定性及含量分析,结果显示随着加工温度升高,丙酮、2-丁醇、辛二烯、己酸和甲硫醚的含量也随之增多。同时,甲基环己烷羧酸、丙酮、2-丁醇和水芹烯在奶粉的加工工艺中出现了大量的损失。由此得出结论,Heracles II超快速气相电子鼻能够实现对不同加工方式牛奶的快速鉴别。     

奶粉中营养元素检测方法的研究进展

奶粉中营养元素的检测是奶粉质量检验的重要组成部分。目前奶粉中营养元素主要有钾、钙、钠、镁、铁、锌、铜、锰、磷、硒、碘元素,各元素的样品前处理方法不一,采用的检测方法使用的分析仪器不同,从而导致检验时间长,与此同时经过学者们的深入研究探索,有部分元素可用同一种前处理方法和同一种分析仪器进行同时测定,从而大大缩短了检验时间,因此奶粉中多元素的同时检测一直是奶粉分析检测领域的重点研究对象。本文着重论述目前国内外婴幼儿奶粉中营养元素的检测方法研究进程,阐述各种方法的基本原理,并对多元素同时测定的样品前处理方法和仪器分析方法进行总结,提出了开展研究微波酸消解样品代替其他前处理方法,采用电感耦合等离子体质谱法(inductively coupled plasma mass spectrometry, ICP-MS)同时测定奶粉中营养元素的新趋势。