乳及乳制品加工中的美拉德反应

针对乳及乳制品在加工和储藏过程中由于发生美拉德反应不仅使乳制品的营养物质受到破坏，还产生对人体有害的物质，在很大程度上影响的乳制品的质量，对乳制品中美拉德反应的历程，产生的标志物及其测定方法等进行了的综述。     

Maillard反应合成咸味香精研究进展

阐明了国内外Maillard反应合成咸味香精的研究进展,并对其目前存在的问题及发展趋势作了进一步的说明。      

Maillard反应合成咸味香精研究进展

阐明了国内外Maillard反应合成咸味香精的研究进展,并对其目前存在的问题及发展趋势作了进一步的说明。     

方格星虫酶解物与不同糖Maillard反应特性及其产物特征风味变化

研究不同种类糖（葡萄糖、麦芽糖、木糖和阿拉伯胶）与方格星虫酶解物（enzymatic hydrolysate of Sipunculus nudus,SEH）在一定条件下（120 ℃、120 min）形成Maillard反应产物的吸光度（A420 nm和A294 nm）、pH值、色差、总/游离氨基酸和荧光强度变化,并结合电子鼻对不同反应产物的特征风味进行分析。结果表明,不同种类糖与SEH反应后,产物褐变度增大、黄色加深、亮度变暗、pH值减小;Maillard反应产物的17 种游离氨基酸和总氨基酸含量较SEH均降低,其中8 种苦味氨基酸含量显著降低,改善了酶解液的苦味;SEH与不同糖反应后的荧光强度显著降低且红移,其三级结构发生改变;且不同糖与SEH的反应程度表现为：木糖＞阿拉伯胶＞葡萄糖＞麦芽糖。电子鼻能够较好地区分SEH与不同糖形成的Maillard反应产物特征风味,发现线性判别分析法区分效果优于主成分分析方法,负荷加载分析显示2号和7号传感器在第1主成分上贡献率较大,6号和9号在第2主成分上贡献率较大,表明氨氧化物、甲烷、硫化氢类成分是区别SEH和Maillard反应产物的主要挥发性特征风味。因此,不同种类糖与酶解物Maillard反应特性及其产物特征风味不同,可根据工艺需求选择合适的糖基供体。     

脯氨酸与葡萄糖Maillard初级反应动力学

用HPLC对脯氨酸与葡萄糖Maillard初级反应动力学进行了研究,结果表明:该反应是一个二级反应,在T=327 K和T=337 K下的总速率常数分别为k=0.257 8 L/(mol·h)(r=0.995 4)和k=0.638 1 L/(mol·h)(r=0.997 4);Es=101.47 kJ/(mol·L).     

葡萄糖/丙氨酸Maillard反应水溶性高分子产物的规模化合成及其在烟草中的应用

为扩大Maillard水溶性高分子产物的产量,考察了规模化合成葡萄糖(Glu)/丙氨酸(Ala)Maillard水溶性高分子产物的条件包括投料比、加热方式、反应时间、分离方法对产物得率及其在卷烟中的加香效果的影响。结果表明:①适宜的规模化合成条件为:投料比Glu/Ala(摩尔比)=1∶1,NaHCO34%,95℃下反应24～30h,醇析法和喷雾干燥法分离;②规模化产品对卷烟的香气量、杂气、浓度、细腻柔和度、刺激性、余味、回甜等方面都有不同程度的改善,尤其是在香气量、杂气和细腻柔和度方面。醇析法产品对香气的改善更明显,而喷雾干燥法产品对口感的改善效果更好。     

谷氨酸和葡萄糖的Maillard反应

研究了由谷氨酸和葡萄糖反应合成烟草增香剂的反应条件对反应产物加香效果的影响。结果表明 :摩尔比为 1∶2的葡萄糖与谷氨酸在 10 0℃、反应 2h的反应产物具有较好的增香效果。GC/MS测定证明 ,在反应体系中添加少量乙醛 ,可促进多种挥发性致香成分的生成 ,且主要生成吡嗪类化合物     

Maillard反应合成香味料机理的研究

文章通过一定花生粕蛋白水解液在葡萄糖(6%)∶氨基酸=1∶1,VB1=0.8%,VC=0.5%,pH5.5,T=180℃条件下,反应60min,所得挥发性成分的分离和检测,进一步从机理方面探讨Maillard反应合成香味料的模式。     

不同鸡肉蛋白肽在Maillard反应中的降解趋势研究

研究了鸡肉蛋白酶解3、6、9、12h产物中不同鸡肉蛋白肽(分子量<10000Da)与葡萄糖Maillard反应中肽降解的趋势。结果表明,不同鸡肉蛋白肽中相同分子量范围的肽段在Maillard反应中的降解趋势相同;而随着酶解程度的加大,鸡肉蛋白肽中各肽段的反应活性增加,12h酶解产物中的鸡肉蛋白肽各肽段均具有最高的反应活性。      

Maillard反应制备虾味香精

利用虾酶解液结合Maillard(美拉德)反应研制虾味香精,利用均匀设计安排实验,根据感官分析找出反应的最佳条件为:温度:115℃、时间:37min、虾酶解液40.00g、葡萄糖6.00g、甘氨酸2.70g、蛋氨酸1.90g、脯氨酸3.00g、丙氨酸3.00g、精氨酸2.90g、酵母提取物4.00g。     

Chemical methods and techniques to monitor early Maillard reaction in milk products; A review

Maillard reaction is an extensively studied, yet unresolved chemical reaction that occurs as a result of application of the heat and during the storage of foods. The formation of advanced glycation end products (AGEs) has been the focus of several investigations recently. These molecules which are formed at the advanced stage of the Maillard reaction, are suspected to be involved in autoimmune diseases in humans. Therefore, understanding to which extent this reaction occurs in foods, is of vital significance. Because of their composition, milk products are ideal media for this reaction, especially when application of heat and prolonged storage are considered. Thus, in this work several chemical approaches to monitor this reaction in an early stage are reviewed. This is mostly done regarding available lysine blockage which takes place in the very beginning of the reaction. The most popular methods and their applications to various products are reviewed. The methods including their modifications are described in detail and their findings are discussed. The present paper provides an insight into the history of the most frequently-used methods and provides an overview on the indicators of the Maillard reaction in the early stage with its focus on milk products and especially milk powders.     

Disappearance of Maillard reaction products during ensilage and rumen fermentation in vitro

The disappearance of Maillard reaction products (MRPs) during ensilage and rumen fermentation was studied. MRPs were prepared by heating mixtures of D ‐glucose and glycine (GG) or D ‐xylose and glycine (XG); lyophilised powder (MW > 1000) was subjected to anaerobic incubation for 24 h with lucerne juice or buffered rumen fluid. Changes in MRPs were assessed by comparing gel filtration profiles before and after incubation, and the proportion of disappeared MRPs was calculated based on the area under the curve. A portion of MRPs, particularly high‐MW fractions, disappeared when incubated with lucerne juice, and the extent was greater (P < 0.01) in XG than in GG. The disappearance of GG was increased (P < 0.01) when ensilage was fortified with added glucose, while that of XG was unaffected with or without the fermentable substrate. Rumen fermentation had little impact on GG and XG, whereas a portion of MRPs disappeared when microbial activity was enhanced by adding lucerne hay to the media. Volatile fatty acid production was unaffected by MRPs in either ensilage or rumen fermentation. These results suggest that the effect on MRPs of anaerobic fermentation may be different between ensilage and rumen digestion. Significant amounts of MRPs would enter the intestine when ruminants are fed hay‐based diets rather than silage‐based diets. © 2000 Society of Chemical Industry     

Preventive effect of fermented Maillard reaction products from milk proteins in cardiovascular health

The aim of this study was to determine the dual effect of Maillard reaction and fermentation on the preventive cardiovascular effects of milk proteins. Maillard reaction products (MRP) were prepared from the reaction between milk proteins, such as whey protein concentrates (WPC) and sodium caseinate (SC), and lactose. The hydrolysates of MRP were obtained from fermentation by lactic acid bacteria (LAB; i.e., Lactobacillus gasseri H10, L. gasseri H11, Lactobacillus fermentum H4, and L. fermentum H9, where human-isolated strains were designated H1 to H15), which had excellent proteolytic and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities (>20%). The antioxidant activity of MRP was greater than that of intact proteins in assays of the reaction with 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt and trivalent ferric ions; moreover, the effect of MRP was synergistically improved by fermentation. The Maillard reaction dramatically increased the level of antithrombotic activity and 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) inhibitory effect of milk proteins, but did not change the level of activity for micellar cholesterol solubility. Furthermore, specific biological properties were enhanced by fermentation. Lactobacillus gasseri H11 demonstrated the greatest activity for thrombin and HMGR inhibition in Maillard-reacted WPC, by 42 and 33%, respectively, whereas hydrolysates of Maillard-reacted SC fermented by L. fermentum H9 demonstrated the highest reduction rate for micellar cholesterol solubility, at 52%. In addition, the small compounds that were likely released by fermentation of MRP were identified by size-exclusion chromatography. Therefore, MRP and hydrolysates of fermented MRP could be used to reduce cardiovascular risks.     

Effect of Maillard reaction products on oxidation products in ground chicken breast

Three amino acid-sugar solutions were adjusted to pH 8.0, heated and lyophilized prior to addition to ground chicken breast (GCB). GCB with no additives, GCB with 0.01% BHT, GCB with 0.1 or 0.2 mg/g glucose heated with arginine, valine, or histidine were prepared. Thiobarbituric acid reactive substances (TBARS), volatiles determined by gas chromatography, and Hunter L*, a* and b* values were monitored over nine days. Multiple linear regression models were used to determine the effects of the studied factors on the corresponding outcome variables. a* values of GCB ranged from 1.60 to 4.90 over nine days of storage. While Maillard reaction products (MRP) lowered oxidation compared to control, no significant difference in TBARS between MRP solutions heated for 8 or 24 h was found. Further, 0.1 mg/g heated glucose-valine mixture decreased aldehydes up to 72.87%. Therefore, shelf-life of GCB could be extended using 0.1 or 0.2 mg/g MRP.     

前表面荧光法在牛奶美拉德反应检测中的应用

在热处理中,牛奶中的乳蛋白容易与乳糖发生美拉德反应,使牛奶的色泽、风味、营养等发生变化。与传统化学检测法相比,前表面荧光法具有快速灵敏、前处理简便等优点。为了评估前表面荧光法在检测牛奶美拉德反应程度上的准确性和适用性,本文对比了不同热处理下牛奶的美拉德反应的荧光图谱和美拉德产物的含量,分析了指标间的相关性。并以前表面荧光法和羟甲基糠醛含量建立模型对商业乳品进行预测,结果良好,为荧光检测的工业应用提供理论依据。结果显示,前表面荧光法可应用于牛奶前中期美拉德产物的无损检测。     

Maillard Reaction in Microwave Cooking: Comparison of Early Maillard Products in Conventionally and Microwave-Heated Milk

The impact of microwave cooking on the formation of early Maillard products was investigated and compared with the effect of conventional cooking, using milk as a test system. Experiments were carried out at controlled temperatures of 80°C and 90°C, respectively, at holding times up to 420min. Furosine, hydroxymethylfurfural (HMF) and lactulose, which are all established indicators to estimate heat damage, were determined. The concentrations of all the heating indicators increased with increasing heating time. For example in the 90°C test series the furosine values rose from 34mglitre⁻¹ (0·5h) to 94mglitre⁻¹ (2h holding time) in the milk heated by microwaves and from 35mglitre⁻¹ (0·5h) to 96mg litre⁻¹ (2h) in the conventionally heated milk. None of the reaction products showed significant differences as between the microwave heating and conventional cooking methods.     

The kinetics of Maillard reaction in lactose-hydrolysed milk powder and related systems containing carbohydrate mixtures

The kinetics of Maillard reaction in lactose-hydrolysed skim milk powder and related systems containing carbohydrate mixtures were analysed. The effect of the increase of water activity and temperature during storage of the commercial product was also evaluated. In systems with two and three carbohydrates, a marked decrease of the reaction rate was observed when monosaccharides were partially replaced by lactose, notwithstanding the fact that the former still remained in a higher proportion than lysine. The rate of available lysine loss in lactose-hydrolysed milk was mostly affected by the presence of galactose. The reaction rate constants at a_w 0.52 and at 37 and 50 °C were higher than at a_w 0.33. However, no significant differences were observed at 60 °C. Temperature is the most important factor to be controlled in order to minimise nutritional deterioration during storage.     

葡萄糖-甘氨酸美拉德反应产物对脂肪氧合酶的抑制作用研究

以葡萄糖和甘氨酸为原料制备美拉德反应产物（Glu/Gly-MRPs）,研究其对大豆脂肪氧合酶（LOX）的抑制作用以及机理。结果表明:随着反应中甘氨酸浓度、反应初始pH、反应温度和反应时间的增大,Glu/Gly-MRPs的褐变程度加深,pH下降,对LOX的抑制作用增强;当甘氨酸浓度大于0.6mol/L、反应体系初始pH高于8.0、反应温度高于110℃、反应时间长于3h时,MRPs对LOX的抑制率均趋于稳定值（80%¹00%）。Glu/Gly-MRPs对LOX酶促反应的迟滞时间具有延长作用,通过Lineweaver-Burk双倒数法确定Glu/Gly-MRPs对LOX的抑制类型为混合型抑制。