Effects of Maillard reaction and its product AGEs on aging and age-related diseases

Maillard reaction(MR)is a non-enzymatic browning reaction commonly seen in food processing,which occurs between reducing sugars and compounds with amino groups.Despite certain advantages based on Maillard reaction products(MRPs)found in some food for health and storage application have appeared,however,the MR occurring in human physiological environment can produce advanced glycation end products(AGEs)by non-enzymatic modification of macromolecules such as proteins,lipids and nucleic acid,which could change the structure and functional activity of the molecules themselves.In this review,we take AGEs as our main object,on the one hand,discuss physiologic aging,that is,age-dependent covalent cross-linking and modification of proteins such as collagen that occur in eyes and skin containing connective tissue.On the other hand,pathological aging associated with autoimmune and inflammatory diseases,neurodegenerative diseases,diabetes and diabetic nephropathy,cardiovascular diseases and bone degenerative diseases have been mainly proposed.Based on the series of adverse effects of accelerated aging and disease pathologies caused by MRPs,the possible harm caused by some MR can be slowed down or inhibited by artificial drug intervention,dietary pattern and lifestyle control.It also stimulates people's curiosity to continue to explore the potential link between the MR and human aging and health,which should be paid more attention to for the development of life sciences.

Maillard reaction affecting immunobinding activity and digestibility of tropomyosin in Alectryonella plicatula food matrix

In recent years,the allergy rate of oysters has surged,and daily food processing methods make it hard to reduce heat resistance and digestive allergy such as tropomyosin(TM).In this study,the Maillard reaction with xylose significantly reduced the IgE binding capacity of Alectryonella plicatula food matrix(AFM),that reduced by(77.81±2.68)%.The study found the Maillard reaction changes the structure of the AFM,in which the content ofα-helix decreased by(24.64±1.46)%.Structural transformation further explains why the Maillard reaction alters the immunobinding activity of AFM.In addition,the Maillard reaction reduces the digestive stability of the AFM and makes TM in the A.plicatula food matrix Maillard reaction products(AFM-MRPs)more easily digested.Based on the above research,10 amino acids on the 7 IgE epitopes of TM were modified.This result indicates that the Maillard reaction reduces the immunobinding activity of the AFM by changing the structure and modifying the amino acids on the epitope.

Curcumin delivery nanoparticles based on Maillard reaction of Haematococcus pluvialis protein/galactose for alleviating acute alcoholic liver damage

The aim of this study is to investigate the feasibility of Maillard reaction products of Haematococcus pluvialis protein and galactose(HPP-GAL)for improving the bioactivities of curcumin(CUR)for alleviating alcoholic liver damage.CUR was embedded into HPP-GAL nanoparticles by the self-assembly of hydrogen bonding and hydrophobic interaction with the particle size around 200 nm.HPP-GAL enhanced the encapsulation efficiency and loading amount of CUR with the value of(89.21±0.33)%and(0.500±0.004)%,respectively.The stabilities of CUR under strong acid,salt ion stability and ultraviolet irradiation conditions were improved by the encapsulation.HPP-GAL-CUR nanoparticles exhibited excellent concentration-dependent in vitro antioxidant activities including DPPH and ABTS scavenging rates,and better protective effect on CUR against gastric acid environment as well as longer release of CUR in simulated intestinal fluid.In addition,the HPPGAL-CUR delivery system possessed liver targeting property due to the existence of GAL,which could effectively alleviate the alcohol-induced liver damage and the inflammation indexes by inhibiting the oxidative stress.Therefore,HPP-GAL-CUR nanoparticles might be a potential candidate system for the prevention of alcoholic liver damage in the future.

Fish Gelatin-Based Film Containing Maillard Reaction Products:Properties and Its Use as Bag for Packing Chicken Skin Oil

Maillard reaction is a non-enzymatic browning reaction and its products(MRPs)have been proven to possess antioxidant properties.This research aimed to produce a fish gelatin-based packaging incorporated with MRPs to retard lipid oxidation in chicken skin oil(CSO)during storage at ambient temperature(28℃–30℃).MRPs produced from fish gelatin and fructose(1:1,90℃,pH 11)showed the highest antioxidant properties compared to those prepared under other conditions.Different glycerol/MRPs ratios(30:0,25:5,20:10,15:15,10:20,5:25,0:30)were incorporated into the film and resulting films were characterized.Glycerol/MRPs at 10:20 ratio was chosen to add into the film prior to bag preparation via heat sealing method.CSO packed in the bag was monitored for lipid hydrolysis and oxidation during 15 days of storage(30℃±0.5℃,RH 52%±5%).After 15 days,quality deterioration was lower in CSO packed in the prepared gelatin bag as evidenced by lower FFA,TBARS,and volatile compounds in comparison with CSO packed in LDPE bag.Fish gelatin film added with MRPs possessed an excellent water vapor barrier property(WV-BP).This finding indicated that MRPs could be used to substitute glycerol and simultaneously could serve as antioxidants for the developed active bag.The novel packaging can be a potential alternative packaging for retarding lipid oxidation of lipid or fatty foods.

Preparation of natural isovaleraldehyde by the Maillard reaction

Isovaleraldehyde possesses malty, fruity, cocoa-like odor and is widely used in fruit, chocolate, coffee flavors. The preparation of natural isovaleraldehyde by the Maillard model reaction was studied in this paper. The effects of the ratio of d-glucose/l-leucine, reaction temperature and pH value on the yield of isovaleraldehyde were explored. The optimum conditions were as follows: n(d-glucose):n(l-leucine) = 4, temperature 150 °C, reaction time 3 h, pH 5. The highest yield of isovaleraldehyde obtained was about 32%.

Management of Maillard reaction-derived reactive carbonyl species and advanced glycation end products by tea and tea polyphenols

Tea as the most consumed beverage in the world has received enormous attention for its promoting health benefits.The deleterious effect ofα-dicarbonyls and AGEs formed in Maillard reaction is also a longterm challenge.The connection between the two topics was the main aim of this review,to address and update the antiglycation effect and mechanism of tea and tea polyphenols.By analyzing recent publications,we have covered across chemistry models,cell lines and animal studies.Tea polyphenols,particularly catechins,showed outstanding antiglycation effect by trappingα-dicarbonyl compounds and impeding AGEs formation.Reduction of carbonyl stress brought alleviation to aging,diabetes,and collagen related diseases or complications through regulation of RAGE expression and subsequent MAPK and TGF-βpathway.Therefore,tea polyphenols can serve as promising natural candidates in the treatment and/or prevention of nephropathy,retinopathy,hepatopathy,hyperglycemia and obesity among others,by their potent antiglycation effect.Further studies need to address on aspects like exact mechanisms,solution of detection obstacles,balance of practical usage and harmful effects such as potential flavor damage and toxicity in food,to gain a comprehensive understanding of antiglycation activities of tea polyphenols and its actual application.

Oxidation combined with Maillard reaction induced free and protein-bound N^ε-carboxymethyllysine and Nε-carboxyethyllysine formation during braised chicken processing

The objective of this work was to investigate the effects of oxidation and Maillard reaction on free and protein-bound N^ε-carboxymethyllysine(CML)and Nε-carboxyethyllysine(CEL)formation during braised chicken processing.It was found that a positive correlation was observed between carbonyl,fat oxidation,Maillard reaction,CML and CEL(P<0.05).The sulfhydryl groups could be used as potential indicators to evaluate the compounds’interaction levels between Maillard reaction and protein oxidation.Frying promoted the formation of lysine(Lys),glyoxal(GO)and methylglyoxal(MGO)(P<0.05);boiling enhanced the formation of GO and MGO(P<0.05)while inhibited the levels of Lys(P<0.05);sterilizing blocked the formation of MGO and Lys(P<0.01)but improved GO levels(P<0.05).Finally,a perspective was concluded that the Maillard reaction combined with oxidation is one of the main reasons for the formation of free and protein-bound CML and CEL during braised chicken processing.

The dynamic changes and mechanisms of Rehmanniae radix processing based on Maillard reaction

Background:Traditional Chinese medicines are usually processed before they are used for clinical treatment.This is done in a way associated with the Maillard reaction.Methods:Based on the Maillard reaction,this paper analyzed the degree of processing of rehmannia root(Rehmanniae radix)relative to the dynamic variation rules of Maillard reaction index parameters,including pH,A420,amino acids,and 5-hydroxymethylfurfural.Furthermore,this study introduced thermal analysis techniques and pyrolysis kinetics to assess the influence of the correlation between processing raw rehmannia root and the Maillard reaction during carbonization.It then went through the whole process of transforming the raw material to end-product in order to explain the scientific connotation of processing it.Results:The results showed that each time rehmannia root was processed,its pH value and amino acid content decreased,while the A420 value and 5-HMF increased.Processing with wine shows a significant difference in these experimental indexes.The position and intensity of the maximum thermal weight loss rate peak of processed rehmannia root at different degrees of processing are different.Comprehensive quantitative 221±0.2°C for processed rehmannia root carbonization was the processing temperature limit.Moreover,the kinetic solution verified that the activation energy corresponding to the carbonization temperature was close to the maximum value of the activation energy of the whole carbonization process,and the optimal mechanism function was g(α)=((1−α)−1/3−1)2.Conclusion:The Maillard reaction occurred during the processing of rehmannia root mixed with carbonization.With each increase of the number of steaming and drying cycles involved in the processing,the level of Maillard reaction increased significantly.The wine-steaming method had a significant effect on the quality of the processed product.

Maillard reaction in Chinese household-prepared stewed pork balls with brown sauce:potentially risky and volatile products

The stewed pork balls with brown sauce(SPB-BS)in China is well known for its delicacy and preferred by consumers.Maillard reaction(MR)is widespread in SPB-BS due to the use of sugar,meat and sauce in the thermal process.However,there is a lack of research on its risk and flavor by MR.By solid phase extraction combined with HPLC-MS,4 kinds of harmful compounds including acrylamide(AA),heterocyclic aromatic amines(HAAs),4-methylimidazole(4-MEI)and furan were analyzed in SPB-BS and their amounts ranged 0.05–0.50 mg/kg.The quantitative formula was proposed to evaluate the risk value of the SPB-BS,after taking into account the content,acceptable daily intake(ADI)and carcinogenicity of each compound.The risk values were in range of 0.57–37.93,suggesting that the risk caused by MR in SPB-BS was low.By head space-solid phase microextraction combined with GC-MS,57 volatile compounds in SPB-BS were identified with the dominant contribution of alcohols,aldehydes,acids and esters.Based on the structures of these compounds and the composition of SPB-BS,lipid oxidation and MR are inferred to be responsible for the formation of the harmful and volatile compounds.In addition,the added sauces and oil provides the main precursors to form the harmful and volatile compounds in SPB-BS,so it is necessary to point out a balance between them in the further study.

Maillard reaction and immunogenicity of protein therapeutics

The recombinant DNA technology enabled the produ-ction of a variety of human therapeutic proteins. Accumulated clinical experience, however, indicates that the formation of antibodies against such proteins is a general phenomenon rather than an exception. The immunogenicity of therapeutic proteins results in inefficient therapy and in the development of undesired, sometimes life-threatening, side reactions. The human proteins, designed for clinical application, usually have the same amino acid sequence as their native prototypes and it is not yet fully clear what the reasons for their immunogenicity are. In previous studies we have demonstrated for the first time that interferon-b （IFN-b） pharmaceuticals, used for treatment of patients with multiple sclerosis, do contain advanced glycation end products （AGEs） that contribute to IFN-b immunogenicity. AGEs are the fnal products of a chemical reaction known as the Maillard reaction or glycation, which implication in protein drugs’ immunogenicity has been overlooked so far. Therefore, the aim of the present article is to provide a comprehensive overview on the Maillard reaction with emphasis on experimental data and theoretical consideration telling us why the Maillard reaction warrants special attention in the context of the well-documented protein drugs’ immunogenicity.

Study on the Regulation of Diorganogermanium Compounds on the Maillard Reaction of Histidine and Glycine by Fluorescence Spectrum

The suppression of diorganogermanium compounds on the Maillard reaction of histidine(His) and glycine (Gly) with glucose has been determined by fluorescence spectrum underphysiological conditions. The title compounds show inhibition for the fluorescence intensity (FI) ofglycosylated andno acids stronger than Ge-132.

热反应条件对葡萄糖-丙氨酸甜香型美拉德反应模拟体系中二羰基化合物及风味物质的影响

目的:探究不同热反应条件(温度、pH、反应时间和底物摩尔比)对葡萄糖-丙氨酸模拟体系中3种重要二羰基化合物(Dicarbonylcompounds,DCs)同步生成规律及对应风味物质的影响。方法:采用邻苯二胺衍生结合HPLC同步测定了葡萄糖-丙氨酸体系中的乙二醛(Glyoxal,GO)、丙酮醛(Methylglyoxal,MGO)和3-脱氧葡萄糖醛酮(3-Deoxyglucosone,3-DG)的含量;采用SPME-GC-MS测定了体系中的5类重要风味化合物。结果:温度升高会促进DCs的生成;碱性条件不利于3-DG的生成但有利于GO和MGO的生成;增加还原糖比例有利于3-DG的生成,而增加氨基酸比例则有利于GO和MGO的生成。结论:在甜香型食品热加工过程中,需要重点关注体系中的MGO。调整加工工艺来控制DCs生成或向危害物转化时,需要重点考虑对酮类和吡嗪类风味物质的影响。

蛋白多肽美拉德反应物稳定乳液的研究进展

乳液被认为是一种用于递送生物活性物质的良好体系,但由于其不稳定,极大地限制了应用。蛋白多肽具有独特的营养价值和生物活性,其结构灵活且易于在油水界面展开和重排,因此蛋白多肽稳定的乳液受到了广泛关注。蛋白多肽作为乳化剂虽然能够形成有效的乳液,但在稳定乳液方面效率较低。有研究发现蛋白多肽美拉德反应物稳定的乳液具有较好的稳定性、理化特性和功能特性。因此,本文对蛋白多肽美拉德反应物稳定乳液的作用机制、理化特性、功能特性、影响乳液稳定性的因素及其在递送体系中的应用进行了详细的阐述,为扩大蛋白多肽乳液在递送生物活性物质中的应用提供理论依据。

微乳液体系中Maillard反应研究

介绍了微乳液的形成机理、微乳液体系中Maillard反应特点以及应用情况,着重讨论了微乳液体系中Maillard反应的影响因素,如表面活性剂、助表面活性剂、油-水界面、含水量、反应物浓度、pH等对反应的影响。

模式体系Maillard反应肉类(牛肉)香精的挥发性成份分析

本研究采用固相微萃取(SPME)与同时蒸馏萃取(SDE),对模式体系Maillard反应肉类 (牛肉 )香精的挥发性成份进行分离,然后应用GC MS对反应产物进行分析,共分离鉴定出 98种挥发性化合物,尤其是分离鉴定出吡嗪、2,6- 二甲基吡嗪、2- 呋喃甲硫醇、2- 甲基 3 -呋喃硫醇、甲基(2 -甲基 3- 呋喃基)二硫醚、双(2- 糠基)二硫醚、双 (2 -甲基 3 -呋喃基 )二硫醚、4 -甲基噻唑、2- 甲基 2 -环戊烯 -1 酮与 -3-甲基- 2 -噻吩基甲醛等关键性肉香(牛肉)化合物等肉香或特征性牛肉风味化合物。

模式体系Maillard反应合成热加工肉类(牛肉)风味料的研究

以牛肉酶解物、L 半胱氨酸盐酸盐、DL 丙氨酸、D 木糖、盐酸硫胺素等为模式体系反应制备热加工肉类风味料 ,采用固相微萃取 (SPME) GC MS对反应产物进行分析 ,共分离鉴定出 71种挥发性化合物 ,尤其是分离鉴定出 2 ,5 二甲基 4 羟基 3 (2H) 呋喃酮、2 乙基 4 羟基 5 甲基 3(2H)呋喃酮、甲基吡嗪、2 ,5 二甲基吡嗪、2 ,6 二甲基吡嗪、4,5 二甲基噻唑、2 乙酰基 3 氨基噻吩、3 甲基 2 噻吩羰基醛、甲基 (2 甲基 -3 呋喃基 )二硫醚、反式茴香醚、5 乙烯基 4 甲基噻唑、四氢 3 甲基 1 ,3 二硫醇 (4 ,5 b)呋喃、十六醛等肉香或特征性牛肉风味化合物。

Comprehensive analysis of advanced glycation end-products in commonly consumed foods:presenting a database for dietary AGEs and associated exposure assessment

Advanced glycation end-products(AGEs)are a group of heterogeneous compounds formed in heatprocessed foods and are proven to be detrimental to human health.Currently,there is no comprehensive database for AGEs in foods that covers the entire range of food categories,which limits the accurate risk assessment of dietary AGEs in human diseases.In this study,we first established an isotope dilution UHPLCQq Q-MS/MS-based method for simultaneous quantification of 10 major AGEs in foods.The contents of these AGEs were detected in 334 foods covering all main groups consumed in Western and Chinese populations.Nε-Carboxymethyllysine,methylglyoxal-derived hydroimidazolone isomers,and glyoxal-derived hydroimidazolone-1 are predominant AGEs found in most foodstuffs.Total amounts of AGEs were high in processed nuts,bakery products,and certain types of cereals and meats(>150 mg/kg),while low in dairy products,vegetables,fruits,and beverages(<40 mg/kg).Assessment of estimated daily intake implied that the contribution of food groups to daily AGE intake varied a lot under different eating patterns,and selection of high-AGE foods leads to up to a 2.7-fold higher intake of AGEs through daily meals.The presented AGE database allows accurate assessment of dietary exposure to these glycotoxins to explore their physiological impacts on human health.

L-阿拉伯糖/半胱氨酸Maillard反应动力学的研究

本文通过模型体系的建立，研究了L-阿拉伯糖/半胱氨酸Maillard反应动力学。利用高效液相色谱-蒸发光散射检测器，分析了Maillard反应产物，比较了不同反应条件下阿拉伯糖/半胱氨酸模型体系中L-阿拉伯糖的残留情况的反应动力学特征。研究表明，pH5、120℃条件下，Maillard反应初期L-阿拉伯糖与氨基酸结合迅速，是一个动力学控制过程;随着反应时间的延长，反应速率趋于稳定，反应速率取决于Amadori化合物分解为产物的速率，是一个热力学控制过程。反应温度对Maillard反应速率的影响大于反应时间，高温可使Maillard反应速率迅速提高。初始pH对Maillard反应影响最大，酸性和弱酸性条件反应缓慢，中性和碱性条件下反应快速。pH5、反应温度120℃时，L-阿拉伯糖的残留率随反应时间的延长而下降，反应时间180 min时残留率为50.53%;pH5、反应时间1 h时，反应温度不同L-阿拉伯糖的残留率不同，在40-100℃范围内残留率变化（70.4%-76.78%）不大，在100-140℃范围内随反应温度的上升残留率迅速下降，140℃时残留率为27.79%;反应温度120℃、反应时间1 h时，酸性条件下不同初始pH，残留率变化不大。但中性及碱性条件下残留率迅速下降，pH9时残留率为15.1%。结论：反应时间对L-阿拉伯糖的残留率影响远不如反应温度和pH，其中pH的影响最为显著。

Density Functional Study on the Mechanism of Amadori Rearrangement Reaction

The reaction mechanism of amadori rearrangement in the initial stage of Maillard reaction has been investigated by means of density functional theory calculations in the gaseous phase and aqueous solution.Cyclic ribose and glycine were taken as the model in the amadori rearrangement.Reaction mechanisms have been proposed,and possibility for the formation of different compounds has been evaluated through calculating the relative energy changes for different steps of the reaction by following the total mass balance.The calculations reveal that the amadori rearrangement initialized via the intramolecular rearrangement,transferring one proton from N（3） to O（4） atom.In the next step,the second proton is also transferred from N（3） to O（4） atom,corresponding to the cleavage of C（4）-O（4） bond and the release of one water molecule.Then another proton is transferred from N（3） to C（5） atom via TS3 with the reaction barrier of 58.3 kcal·mol-1 after tunneling the effect correction calculated at the B3LYP/6-31＋G（d） level of theory,and this step is rate limiting for the whole catalytic cycle.Ultimately,the product is generated via keto-enolic tautomerization.Present calculation could provide insights into the reaction mechanism of Maillard reaction since experimental evaluation of the role of intermediates in the Maillard reaction is quite complicated.

Maillard Products Formed from Chicken Fat Oxidants and Amino Acids Act as a Flavor Enhancer in Comminuted Chicken Products

Lipid oxidation and degradation are generally recognized as unfavorable reactions in food processing. However, lipids can be utilized to produce meat-like flavorings through reaction with amino acids after degradation to carbonyls such as aldehydes and ketones. The fatty acids in chicken fat mainly comprise palmitic acid, oleic acid and linoleic acid. After being heated at 120 ~C for 3 h, the degraded carbonyls of chicken fat were reacted with cysteine, alanine, glycine and thiamine to form a chicken-like flavoring. The key aromatic components of the flavoring were identified by GC-MS. In the overall volatile profile, 22 kinds of compound were detected, among which 2-furanmethanol was formed by the Maillard reaction, 1-（2-furanyl）-ethanone by cyclization and 2,4,6-trimethyl-l,3,5-trithiane by the Strecker degradation of cysteine. Dihydro-2-methyl-3（2H）-furanone, dihydro-2-methyl- 3（2H）-thiophenone, 2-acetyl-lH-pyrroline and 4-methyl-5-thiazoleethanol were the degradation products of thiamine. The prepared chicken flavoring was added to comminuted chicken product （CCP）. GC-MS analysis and sensory evaluation showed that the flavor and odor of the CCP were greatly enhanced.