酶解小麦蛋白产物-还原糖美拉德反应的光谱研究

采用紫外-可见吸收光谱和荧光光谱研究了酶解小麦蛋白产物与还原糖不同加热条件下的美拉德反应及其产物.美拉德反应在紫外区240和294 nm产生两个特征峰,荧光的最大激发和发射波长为347和450 nm;随反应进行,紫外光吸收和荧光强度迅速增加,表明美拉德反应进入高级阶段,产生的糠醛类、呋喃酮类、吡喃酮类、噻吩类及噻唑类等小分子物质表现较大的积累速率.温度升高,强度增加速率增大.在较高温度时,紫外光吸收出现最大平稳值;荧光强度则到达最大值后降低,表明小分子物质间或与肽聚合生成大分子黑素类物质,小分子物质的积累表现消除速率,反应进入终级阶段.     

生物质热解液化与美拉德反应

对生物质热解液化和美拉德反应进行了介绍,指出美拉德反应不仅存在于生物质热解液化过程中,而且通过引入适量氨等调控措施,可以促进美拉德反应有选择性地生成吡嗪类杂环化合物等高值化学品,然后再通过分级冷凝将生物油分为化工生物油和燃料生物油,前者用于分离提取高值化学品,后者用于锅炉和窑炉的燃料.引入美拉德反应后,生物质热解液化技术经济性将会得到根本性的改善.     

Agilent 6410三重串联四极杆质谱检测中国食品中的丙烯酰胺

丙烯酰胺是一种具有神经毒性的小分子化合物,它主要由游离的天门冬酰胺在食品加工过程中通过美拉德反应形成[1].     

紫花苜蓿叶蛋白抗氧化产物的制备及其抗氧化活性的研究

以紫花苜蓿叶蛋白为原料,葡萄糖为改性物,以总还原能力,DPPH·清除率与HO·清除率为指标,湿热美拉德反应为改性方法,在单因素试验基础下探究反应体系pH值、反应底物配比、温度及时间对紫花苜蓿叶蛋白抗氧化活性的影响。结果表明在pH=9,底物配比(m紫花苜蓿叶蛋白∶m葡萄糖)为2∶1,反应温度为80℃,反应时间为60 min时美拉德产物(改性之后的紫花苜蓿叶蛋白)的抗氧化活性最显著。在最优单因素条件下未改性的紫花苜蓿叶蛋白总还原能力为0.84,DPPH·清除率为1.45%,HO·清除率为2.18%。在最优单因素条件下改性之后的紫花苜蓿叶蛋白总还原能力达到1.10,DPPH·清除率达到75.10%,HO·清除率达到39.70%,与未改性的蛋白相比总还原能力提高了0.31,DPPH·清除率提高了50.80%,HO·清除率提高了17.21%。通过测定在不同单因素条件下美拉德产物的褐变程度、中间产物、接枝度等,表明紫花苜蓿叶蛋白与葡萄糖之间发生了美拉德反应。     

表面等离子体共振免疫传感器在蛋白质检测中的应用及其研究进展

表面等离子体共振(SPR)技术是20世纪90年代发展起来的一种新型技术,应用SPR原理可检测生物传感芯片上配位体与分析物之间的相互作用情况,在生命科学、医疗检测、药物筛选、食品检测及环境监测等领域具有广泛的应用需求.SPR技术可与免疫传感器结合,利用抗原抗体的特异性反应可用于各种蛋白质抗原的检测.本文重点总结了SPR免疫传感器在食品及医疗领域蛋白质检测的应用,综述了近年来SPR免疫传感技术在这该领域的研究热点及进展.     

基于质谱的蛋白质组学技术在食品真伪鉴别及品质识别方面的应用

蛋白质组学作为后基因组时代的一个新研究方向,近几年发展迅速,目前已应用于多个领域,在食品品质检测和安全控制方面成为有力的研究工具。蛋白质组学为食品科学的相关研究打开了新思路,不仅可以鉴定蛋白质种类,还可进行蛋白质定量,为分析不同物种、产地、成熟阶段的食品蛋白质组分和含量提供了可能。蛋白质组学研究手段多样,质谱是常用技术之一。该文介绍了蛋白质组学的概念、分类、研究技术以及常见蛋白质数据库,综述了基于质谱的蛋白质组学技术在真伪鉴别和品质检测方面的应用,涉及海鲜、肉制品、奶制品、保健食品及高附加值食品等多种食品,并对蛋白质组学的发展进行了展望。     

基于OBE理念的混合式教学模式在“食品化学”课程教学中的实践

基于OBE教学理念,在食品化学课程教学中探索了混合式教学模式,从课程目标确立、教学内容优化、课程资源建设、课程考核、课程目标达成度等方面进行系统的教学设计。以知识点美拉德反应的教学为例介绍了混合式教学实施过程,并对改革效果进行了分析。实践表明：基于OBE理念的混合式教学模式有利地促进了学生对知识的掌握,提升学生综合能力,取得了显著的教学效果。     

水发食品中甲醛现场测定的样品快速前处理新方法研究

提出了一种用于现场测定水发食品中甲醛含量的样品快速前处理新方法,采用乙酸锌和亚铁氰化钾沉淀样品中的蛋白质和脂肪,在弱酸性介质和沸水浴条件下提取了样品中的甲醛,并与乙酰丙酮立即发生显色反应.研究了不同样品前处理方法对甲醛提取和测定的影响,探讨了水发食品中的甲醛本底值及其是否被人为添加甲醛的判断标准.此方法的特点是样品前处理与显色反应同时进行,在10min内即可完成对水发食品中甲醛含量的定量测定.     

缩醛/缩酮的合成研究进展

民以食为天。然而,鲜有中文文献专业、系统地介绍与食物相关的化学反应,这无疑导致化学课程的教学脱离现实生活,阻碍了大众透过现象看到食物背后的本质。因此,本文重点介绍了为食物带来独特美味及色泽的非酶褐变反应,主要包括焦糖反应、美拉德反应、维生素C的氧化反应等;并从化学的角度探讨食物中与医学相关的分子转变现象,如食盐中碘在体内的转化,反式脂肪酸对健康的影响,酒精的代谢过程等。使化学课程的教学密切联系现实生活,为化学与食品科学、医学等学科之间架起桥梁。     

蛋白质的研究历程与诺贝尔科学奖

介绍蛋白质研究的发展历程,并结合诺贝尔科学奖的获奖历史,解读基因与蛋白质、蛋白质的结构与功能以及蛋白质与生命活动等方面的关系。     

松香胺类衍生物在非表面活性剂方面的应用研究

综述了近年来国内外松香胺类衍生物在非表面活性剂方面的应用研究进展,主要包括催化特定氧化反应、手性反应及手性拆分、Maillard反应、抗菌活性、离子识别、施胶、废水处理、缓释、缓蚀、助焊剂等方面。     

Baking,Ageing, Diabetes: A Short History of the Maillard Reaction

The reaction of reducing carbohydrates with amino compounds described in 1912 by Louis‐Camille Maillard is responsible for the aroma, taste, and appearance of thermally processed food. The discovery that non‐enzymatic conversions also occur in organisms led to intensive investigation of the pathophysiological significance of the Maillard reaction in diabetes and ageing processes. Dietary Maillard products are discussed as “glycotoxins” and thus as a nutritional risk, but also increasingly with regard to positive effects in the human body. In this Review we give an overview of the most important discoveries in Maillard research since it was first described and show that the complex reaction, even after over one hundred years, has lost none of its interdisciplinary actuality.     

Maillard反应的高分子产物的研究进展

Maillard反应产物由于其天然性和独特的香味,使其在食品和烟草领域的应用倍受关注.目前,对Maillard反应产物中的小分子化合物的研究已经比较透彻,但是高分子产物的结构及形成机理尚不清楚.虽然Maillard高分子产物及其复杂,但人们通过膜透析、凝胶柱层析等分离方法,对其提纯分级后,再运用凝胶渗透色谱、元素分析、放射性同位素标记、紫外-可见光谱、红外光谱、核磁共振(NMR)、热裂解等分析手段对其进行表征,对Maillard高分子产物的结构和形成机理有了一定的了解.本文对Maillard反应的高分子产物的分离提纯方法、分析表征方法和分子结构的假设模型三方面的研究进展进行了综述.     

Novel approaches to the analysis of the Maillard reaction of proteins

The Maillard reaction comprises a complex network of reactions which has proven to be of great importance in both food science and medicine. The majority of methods developed for studying the Maillard reaction in food have focused on model systems containing amino acids and monosaccharides. In this study, a number of electrophoretic techniques, including two-dimensional gel electrophoresis and capillary electrophoresis, are presented. These have been developed specifically for the analysis of the Maillard reaction of food proteins, and are giving important insights into this complex process.     

Key Aspects of Amadori Rearrangement Products as Future Food Additives

Flavor is one of the most important factors in attracting consumers and maximizing food quality, and the Maillard reaction (MR) is highly-involved in flavor formation. However, Maillard reaction products have a big drawback in their relatively low stability in thermal treatment and storage. Amadori rearrangement products (ARPs), MR intermediates, can alternatively act as potential flavor additives for their better stability and fresh flavor formation ability. This review aims to elucidate key aspects of ARPs’ future application as flavorings. The development of current analytical technologies enables the precise characterization of ARPs, while advanced preparation methods such as synthesis, separation and drying processes can increase the yield of ARPs to up to 95%. The stability of ARPs is influenced by their chemical nature, pH value, temperature, water activity and food matrix. ARPs are associated with umami and kokumi taste enhancing effects, and the flavor formation is related to amino acids/peptides of the ARPs. Peptide-ARPs can generate peptide-specific flavors, such as: 1,6-dimethy-2(1H)-pyrazinone, 1,5-dimethy-2(1H)-pyrazinone, and 1,5,6-trimethy-2(1H)-pyrazinone. However, further research on systematic stability and toxicology are needed.     

Molecular Shape Analysis of a Maillard Reaction Intermediate

Abstract

The Maillard (browning) reaction involving the polycondensation of sugars and amino acids is believed to be an important abiotic pathway for humic substance formation in nature. However, a major drawback is that the Maillard reaction is extremely slow at temperatures encountered under normal environmental conditions. In order to elucidate some details of this process molecular shape analysis was applied to investigate the initial reaction between D-glucose and glycine to form the Amadori compound fructosylglycine which is an intermediate product in the Maillard reaction. The structure of the Amadori compound was optimized at a quantum mechanical level and its ground state electron energy calculated. Molecular Iso-Density Contours (MIDCO's), electron density contour surfaces of constant electron density, were constructed for D-glucose, glycine and fructosylglycine in order to study the steric conditions for the reaction. The calculations indicate that the Amadori compound and water on one hand and the separate entities D-glucose and glycine on the other hand are very similiar to each other in terms of their ground state energy. This agrees with the experimental observation that the reaction between D-glucose and glycine to form the Amadori compound is slow.     

Kinetics of Maillard reaction in a chicken meat model system using a multiresponses modeling approach

This research aimed to study the Maillard reaction pathway in chicken meat. Owing to the complexity of real chicken meat, which is composed of many different types of amino acids and reducing sugars, the experiment was initiated with a glucose/lysine model system with the same concentration ratio of reactants as found in chicken meat. By considering glucose as the rate-limiting substrate, a kinetic model of the glucose/lysine model system was developed. Methylglyoxal (MG) was found to be the principal important α-dicarbonyl compound intermediates that further reacted to form melanoidins. Pyridine was a major volatile compound in this model system. The optimized kinetic model was then further validated in a chicken extract, for which the Maillard reaction mechanism has not been elucidated. However, the kinetic model of the glucose/lysine system could not explain the Maillard reaction in the chicken extract, presumably because both types of intermediates and reaction pathway depend on the reactants. Thus, a kinetic model of the Maillard reaction in the chicken extract was developed based on the main types of detected intermediates. Overall, MG was the central intermediate and acted as a substrate for the formation of furfural, volatile compounds, melanoidins, and unknown carbonyl compound(s) (C_n). Pyrazines and aldehydes were the major volatile compounds in the chicken extract.     

热重-固相微萃取/气相色谱-质谱联用研究葡萄糖/天冬酰胺模拟体系非水相Maillard反应

利用热重-固相微萃取/气相色谱-质谱(TG-SPME/GC-Ms)联用对葡萄糖/天冬酰胺模拟体系非水相Maillard反应热学性质进行了研究,并分析了模拟体系46种热解逸出挥发性产物相对含量的动态变化情况.探讨了有效减少Maillard反应产物丙烯酰胺的方法.结果表明:葡萄糖/天冬酰胺模拟体系非水相Mail-lard反...     

荧光法研究Ge—132对苯丙氨酸Maillard反应的抑制作用

哺乳动物体内氨基酸及蛋白质的非酶糖化反应（Ｍａｉｌａｒｄ反应）与糖尿病及其并发症的关系已引起广泛关注［１］，β－羧乙基锗倍半氧化物（Ｇｅ－１３２）具有预防糖尿病和调节糖代谢的作用［２］，研究Ｇｅ－１３２对Ｍａｉｌａｒｄ反应的抑制作用对于开发防治糖尿病...