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.

美拉德反应产物(Maillard Reaction Products MRPs)的生理活性及增量的技术措施

综述了美拉德反应产物抗氧化性能及重要的杂环类化合物—四甲基吡嗪阻抑肝细胞纤维化的作用,介绍了中国白酒中美拉德反应产物的分布,阐述了增加上述产物的技术措施。

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.

Effect of Maillard Reaction Products (MRP) on Chlorophyll Stability in Green Peas

Maillard Reaction Products (MRP) was prepared from glucose and glysine heated at 90°C in air circulating oven for 12 hours. The effect of MRP on chlorophyll stability in green peas was investigated. The addition of Maillard Reaction Products (MRP) decreased the loss of chlorophyll a, chlorophyll b and total chlorophyll. The conversion of pheophytin and pyropheophytin were also reduced by the addition of MRP.

Flavor changes in Lentinus Edodes enzymatic hydrolysate maillard reaction products with different sugars by gas chromatography‐ion mobility spectrometry

The characteristic flavor of the enzymatic hydrolysate of Lentinus edodes,which was involved in the Maillard reaction by xylose,fructose,glucose,sucrose,mannose,maltose,vitamin C(VC)and L-arabinose,was determined and analyzed by gas chromatography-ion mobility spectroscopy(GC-IMS).The characteristic flavor fingerprints of Maillard reaction products(MRPs)of L.edodes enzymatic hydrolysate were constructed.The differences in the characteristic flavors of Maillard reaction with different reducing sugars and VC were compared.The main characteristic flavor,characteristic peak,characteristic marker substance and content were determined,a principal component analysis(PCA)of volatile organic compounds(VOCs)was carried out.The results showed that there were 42 kinds of monomers and some dimers of volatile compounds in the samples including 17 aldehydes,5 alcohols,7 ketones,2 esters,2 acids,7 other compounds and 2 ethers.The volatile VOCs of the sample with added sucrose,VC and L-arabinose were significantly higher than those of the enzymatic hydrolysate of L.edodes.After the Maillard reaction,the flavor of the hydrolysate was significantly improved,and the main components changed significantly.

Maillard反应前体物质参与木质素微生物转化产物的FTIR光谱特性

腐殖质(HS)是由各类前体物质缩聚而成,前体物质是调控HS形成的关键。Maillard反应前体物质能否对木质素转化、HS形成有促进作用有待验证。鉴于此,采用液体摇瓶培养法,以木质素培养液为研究对象,通过添加邻苯二酚、葡萄糖和甘氨酸的单一及组合溶液,启动120 d的液体摇瓶培养,采用离心法收集上清液(细胞代谢产物)和沉淀(菌体残留物),分析两者性质并深入研究菌体残留物FTIR的光谱特性,系统评价各前体物质对木质素向HS转化的贡献。结果表明:(1)在木质素培养液中添加甘氨酸,历经液体摇瓶培养更有利于细胞代谢产物有机分子的缩合,使其结构趋于复杂,而邻苯二酚参与的4个处理及单独添加葡萄糖更易促进细胞代谢产物的降解,使其分子结构更加简单。与作为空白对照(CK)的无菌去离子水相比,外源添加Maillard反应前体物质能够促进细胞代谢产物矿化,使总有机碳(total organic carbon,TOC)含量下降,单一添加邻苯二酚能够使细胞代谢产物TOC含量始终高于其他处理;(2)添加Maillard反应前体物质可显著提升木质素微生物转化形成菌体残留物的回收率,单一添加邻苯二酚的菌体残留物回收率提升幅度最大,而邻苯二酚、葡萄糖和甘氨酸三者组合溶液对菌体残留物回收率的提升幅度最小,葡萄糖和甘氨酸的组合溶液使菌体残留物回收率在整个培养期间始终处于最高水平。添加Maillard反应前体物质使菌体残留物TOC含量的增加幅度小于CK,尽管如此,培养结束时,邻苯二酚参与的4个处理、葡萄糖和甘氨酸组合溶液的添加使菌体残留物TOC含量显著高于CK;(3)木质素经微生物转化形成的菌体残留物拥有羟基O—H、不对称脂族—CH_(3)、对称脂族—CH_(2)—、芳香碳C C及多糖类物质,与土壤胡敏酸有着相似的FTIR特征,但其分子缩合度尚无法达到土壤胡敏酸的复杂程度。各处理在完成培养后,菌体残留物中的羟基含量有着不同程度增加,而多糖含量有所下降,单一甘氨酸以及葡萄糖和甘氨酸组合溶液的添加使菌体残留物的脂族化程度提高,而邻苯二酚参与的4个处理及单独添加葡萄糖可使菌体残留物中的芳香碳比例进一步提高。综上,添加Maillard反应前体物质可促进细胞代谢产物矿化,使TOC含量下降、提高菌体残留物回收率,同时使其羟基含量增加、多糖含量降低,不同前体物质对菌体残留物脂族化和芳香化的影响规律不同,邻苯二酚参与的4个处理及单一添加葡萄糖可使菌体残留物中的芳香碳比例提高。

Effective Components of Chinese Herbal Compound Decoction and Maillard Reaction

This paper intends to explore the color changes considered to be Maillard reaction during the process of Chinese herbal medicine.The Maillard reaction products(MRPs) are often in substantial proportions of Chinese herbal compound decoctions but their effects are often neglected.By considering the effects of MRPs in studies of effective components on Chinese herbal compounds,a new perspective is established in future researches of Chinese herbal compound decoctions.

Stability of β-carotene microcapsules with Maillard reaction products derived from whey protein isolate and galactose as coating materials

The stability of β-carotene microcapsules using Maillard reaction products（MRPs） derived from whey protein isolate（WPI） and galactose as coating materials, was studied under the varying environmental conditions of temperature, pH, air, incandescent light, and ultraviolet（UV） light.Scanning electron microscopy showed that microcapsules prepared by WPI-galactose MRPs displayed a smooth and less concave-convex surface and that the particle size（D_（50）） of the microcapsules made with WPI-galactose MRPs was smaller than those made with WPI-galactose mixture.The storage stability of β-carotene microencapsulated in WPI-galactose MRPs was remarkably better than that of β-carotene microencapsulated in the WPI-galactose mixture and that of β-carotene crystal, in respect of temperature, pH, air, incandescent light, and UV light measurements.When the storage temperature was increased from 5 to 105 ℃, the retention rate of β-carotene microcapsules significantly decreased（P〈0.05）.When p H values were increased from 1 to 12, the β-carotene retention rate of the microcapsules significantly increased and afterward decreased.Compared with the retention rate of β-carotene microencapsulated in a WPI-galactose mixture, the retention rate of β-carotene microencapsulated in WPI-galactose MRPs was at a maximum between pH 8 and 9.Under the actions of air, incandescent light, and UV light, the retention rates of β-carotene microcapsules in WPI-galactose MRPs and WPI-galactose mixture, as well as in β-carotene crystal, decreased significantly as the storage time increased（P〈0.05）.Therefore, the use of WPI-galactose MRPs as coating materials can aid in improving the storage stability of β-carotene microcapsules.

Impact and inhibitory mechanism of phenolic compounds on the formation of toxic Maillard reaction products in food

As one of the dominant reactions occurring during thermal treatment of food, the Maillard reaction not only leads to the formation of aroma, browning color and taste compounds, but also contributes to the formation of some unpleasant toxic substances including acrylamide,heterocyclic amines and advanced glycation end products.Polyphenols, one of the most abundant antioxidants in the human diet, are contained in different kinds of foods. In this review, some recent studies on the impact of dietary polyphenols on the formation of acrylamide, heterocyclic amines and advanced glycation end products formed during the Maillard reaction are summarized, including the research work conducted with both chemical model systems and real food model systems; the possible inhibitory mechanisms of different polyphenols are also summarized and discussed in this review. Basically we found that some dietary polyphenols not only scavenge free radicals, but also react with reactive carbonyl species,thus lowering the formation of toxic Maillard reaction products. This review provides a useful theoretical foundation for the application of polyphenols in food safety, and suggests some directions for further study of natural products as inhibitors against the formation of toxic substances in thermally processed food.

Effects of chitosan oligosaccharide-nisin conjugates formed by Maillard reaction on the intestinal microbiota of high-fat diet-induced obesity mice model

Objectives:The goal of this study was to evaluate the modulatory effect of chitosan oligosaccharide-nisin conjugate(CON-C)on intestinal microbiota of human flora-associated(HFA)mice and also reveal its effect towards the high-fat diet(HFD)-induced obesity.Both Chitosan oligosaccharides and nisin showed great potential in modulating the intestinal microbiota,so it is worth to explore whether the modulation effect of chitosan oligosaccharide could be improved by covalently binding with nisin.Materials and Methods:CON-C was prepared by heating the mixed solution of chitosan oligosaccharide and nisin at 80℃ and pH 2.0 for 24h.The structure of CON-C were analyzed by Fourier transform-infrared spectroscopy(FT-IR)and X-ray diffraction(XRD).The CON-C’s anti-obesity effect and modulatory effect toward intestinal microbiota were analyzed using human flora-associated(HFA)mice model.Results:CON-C could alleviated HFD-induced gut dysbiosis,by significantly decreasing the numbers of Bifidobacterium and Lactobacillus/Enterococcus spp.,and increasing the numbers of Bacteroides-Prevotella and Clostridium groups.CON-C could also enriched the most differentially expressed genes through KEGG pathways of biosynthesis of amino acids,two-component system,and ATP binding cassette(ABC)transporters.Conclusions:The improved therapeutic effect of CON-C against HFD-induced obesity has been approved,and hence,CON-C has a great potential to be utilized as a functional food ingredient in reducing body weight.

Quantification of Chinese yam processing methods based on pyrolysis characteristics and its relation to Maillard reaction

Objective:Chinese yam(Shanyao in Chinese,SY)as one of the representatives for Chinese medicines can be used as both of medicine and food with rich nutritional and medicinal value.Most of Chinese herbal medicines need to be processed prior to be used in clinical practice.SY was divided into Maoshanyao(Hairy Shanyao,MSY)and Guangshanyao(Smooth Shanyao,GSY)based on different processing methods at the place of origin,and it also could be processed as stir-fried SY and bran stir-fried SY to meet the different clinical use.Moreover,during the processing of Chinese herbal medicines,more complicated Maillard reaction occurs compared to food processing.Therefore,the objective of this research is to quantify the firepower of SY processing,and combined this with the relevant parameters of Maillard reaction.Methods:The MSY and GSY produced in Shanxi and Henan Provinces were chosen as the research objects.By using thermal analysis technology,we first established the correlation between pyrolysis and processing of SY and its mixtures.We also quantified the firepower of Shaoyao processing,and combined this with the relevant parameters of Maillard reaction(p H value,amino acid,and 5-HMF)and the changes in medicinal ingredients(allantoin).Results:The SY was mainly fried with moderate-fire(190°C-200°C),and the starting temperatures of different SY–ingredient mixtures were(176.3±5.33)°C for(honey)bran,and(205.9±8.05)°C for rice.The upper limits of processing temperature were(289.9±6.47)°C for(honey)bran and(298.9±1.15)°C for rice.The cooking time was(10.80±1.76)min for soil stir-fry,(10.31±1.06)min for bran stir-fry,and(8.43±0.68)min for rice stir-fry.Moreover,the p H values and the content of 5-HMF were increased(P<0.001),while the content of glycine was decreased significantly(P<0.001)after processing.Conclusion:The results verified and quantified the firepower of traditional processing of SY,and also provided scientific reference for other studies related to SY processing.