Influence of pH,NaCl and pre‐incubation on utilisation of surimi wash water in generation of antioxidative material by using the Maillard reaction

Maillard reaction products (MRPs) were generated from reaction mixtures of surimi wash water (SWW) with glucose or fructose (5%w/v) heated at 95 °C for 2–12 h. The effects of pH, NaCl and pre‐incubation of SWW on the Maillard reaction and antioxidant capacity of MRPs were investigated. The antioxidative capacity of MRPs was determined by measuring free DPPH° radical scavenging activity and reducing power. The highest colour intensity (OD₄₂₀) as well as antioxidative capacity was noted in the reaction mixture containing fructose at pH 9.0. The addition of NaCl (0.5–2.5%w/v) caused reduction in browning intensity but enhanced antioxidative capacity of the MRPs. Pre‐incubation of SWW at 45 °C for 4 h decreased soluble protein but increased the Maillard reaction and antioxidative capacity of MRPs. A positive effect of salt or pre‐incubation of SWW on the antioxidative capacity of MRPs was not associated with the soluble protein content in the reaction mixture.     

酪蛋白-木糖体系美拉德反应产物的抗氧化活性

研究评价了由酪蛋白-木糖模拟体系产生的美拉德反应产物的抗氧化活性,考察了反应过程中体系的pH、褐变和中间产物的变化,并测定了美拉德反应产物对金属离子(Cu2+和Fe2+)的螯合能力、自由基清除能力(.OH、DPPH.和ABTS.)以及其还原能力。结果表明,模拟体系的酸度和褐变均随反映的进行而逐渐增加,中间产物在反应初期大量形成;美拉德反应产物对Fe2+的螯合能力要明显强于对Cu2+的螯合能力;美拉德反应产物对DPPH.和ABTS.具有较强的清除作用,而对.OH的清除作用较弱;美拉德反应产物的还原能力随反应时间的延长而逐渐增大。     

Inhibition of enzymatic browning in actual food systems by the Maillard reaction products

BACKGROUND: The Maillard reaction occurring between amino acids and sugars produces neo‐formed compounds having certain levels of antioxidant activity depending on the reaction conditions and the type of reactants. The objective of this study was to investigate enzymatic browning inhibition capacity of Maillard reaction products (MRPs) formed from different amino acids including arginine (Arg), histidine (His), lysine (Lys) and proline (Pro). RESULTS: The inhibitory effects of the MRPs on polyphenol oxidase (PPO) were determined. The total antioxidant capacity (TAC) of MRPs derived from different amino acids were in the order Arg > His > Lys > Pro. The TAC and PPO inhibition of MRPs were evaluated as a function of temperature (80–120 °C), time (1–6 h) and pH (2–12). Arg‐Glc and His‐Glc MRPs exhibited strong TAC and PPO inhibition. Increasing temperature (up to 100 °C) and time also increased TAC and PPO inhibition. Kinetics analysis indicated a mixed type inhibition of PPO by MRPs. CONCLUSION: The results indicate that the MRPs derived from Arg and His under certain reaction conditions significantly prevent enzymatic browning in actual food systems. The intermediate compounds capable of preventing enzymatic browning are reductones and dehydroreductones, as confirmed by liquid chromatographic–mass spectrometric analyses. Copyright © 2010 Society of Chemical Industry     

The inhibition effects of reactive oxygen species by Maillard reaction products in Caco‐2 cells

Maillard reaction products (MRPs) were prepared by heating a mixture of rice starch with different dextrose equivalents (DE 10, 30, 50 and 70) and glycine. The glycine was added to the sample pastes at the same molar concentration as the sugar contained in each sample. As the dextrose equivalent of rice starch increased, the browning intensity and fluorescence of the MRPs increased. The antioxidant properties of the MRPs were investigated by DPPH radical scavenging activity, reducing power, and phenolic content in a chemical system, and were evaluated by measuring reactive oxygen species levels and antioxidant enzymes activities in Caco‐2 cells. The darkest MRPs, MRPs‐4, showed the highest antioxidant activity and phenolic content among the samples; in addition, it inhibited the cellular oxidative stress. The decrease of cell viability and antioxidant enzymes activities caused by reactive oxygen species and apoptosis were recovered by MRPs‐4. Actually, the addition of the MRPs suppressed apoptosis by decreasing the proportion of cells in the sub‐G1 phase. Therefore, these MRPs, as compounds formed by the Maillard reaction, are considered to possess an effective antioxidant activity against oxidizable substrates.     

Effect of Maillard reaction products prepared from glucose–glycine model systems on starch digestibility

The Maillard reaction is one of the most important phenomena occurring spontaneously during food processing and storage. However, research on the effects of Maillard reaction products (MRPs) on starch hydrolysis remains insufficient. To investigate the effects of MRPs on in vitro starch digestibility, the characteristics of glucose–glycine model system containing MRPs and digestive enzyme activities by MRPs were measured. MRPs were prepared by heating of glucose–glycine mixture solution at 90°C for different times (0, 1, 3, 9, 18, 24, and 48 h). As the Maillard reaction proceeded, browning intensity, and furosine and hydroxymethylfurfural content increased, whereas pH value decreased. The reducing power of MRPs was increased as the Maillard reaction progressed, and MRPs produced in 18 and 24 h showed the highest values (both 1.2). In MRPs heated for 48 h, the reducing sugar content and hydrolysis index were lowest values (88.6 and 87.0%) among the samples. The activity of digestive enzymes significantly decreased by adding of MRPs, as the browning of added MRPs increased. Therefore, MRPs seem to be contributed to decrease in starch digestibility, as shown by an enzymatic digestion result.     

Effect of substrate ratios and temperatures on development of Maillard reaction and antioxidant activity of silver carp (Hypophthalmichthys molitrix) protein hydrolysate–glucose system

The study of antioxidant activity of the hydrolysates is necessary during its processing in which Maillard reaction would often occur. To understand the effect of Maillard reaction on antioxidant activity of silver carp protein hydrolysates (SPH), the Maillard reaction products (MRPs) were prepared at different ratios between SPH and glucose by Maillard reaction in powdered state, respectively. MRPs possessed a strong 2, 2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging activity and reducing power (P < 0.05). The hydrolysate and glucose heated with the ratio of 2:1 at 60 °C showed high browning intensity and good antioxidant properties (P < 0.05). According to the correlation coefficients of variables included in the hydrolysate–glucose system, good correlations were observed among the antioxidant activities, the absorbance at 294 nm and the loss of free amino groups. The results suggested that Maillard reaction has a good potential to improve the antioxidant activity of SPH.     

Antioxidant capacity of maillard reaction products formed by a porcine plasma protein hydrolysate-sugar model system as related to chemical characteristics

This study investigated the chemical characteristics and antioxidant properties of Maillard reaction products (MRPs) prepared by porcine plasma protein hydrolysate (PPH) with three monosaccharides (glucose, fructose, and galactose) at 95°C for different lengths of time (0–6 h). The results revealed that the pH value and free amino group content decreased (p<0.05), whereas the color (redness and yellowness), browning intensity, and intermediate products increased as the reaction time increased (p<0.05). There was an obvious increase in the reducing power, 2,2′-aminodi(2-ethyl-benzothiazoline sulfonic acid-6)ammonium salt (ABTS) radical and hydroxide radical scavenging activities of the MRPs with increasing heating time (p<0.05). The PPH-galactose combination rendered a higher browning intensity, intermediate products and antioxidant activities than the PPH-glucose or PPH-fructose combination. The reducing power, ABTS and hydroxyl scavenging activities were significantly correlated with the color, the UV absorbance and the browning intensity in each model system. The results indicate that the Maillard reaction could improve the antioxidant capacity of PPH.     

美拉德反应产物的褐变、荧光吸收及抗氧化性的研究

采用以还原糖-氨基酸(木糖/葡萄糖分别与甘氨酸、赖氨酸、谷氨酰胺、半胱氨酸)模式美拉德反应(Maillard Reaction,MR)制备得到美拉德反应产物(MRPs),研究反应条件对MRPs的褐变程度、荧光吸收强度以及其抗氧化活性的影响,并分析MRPs的光学特征与抗氧化活性之间的联系。结果表明,还原糖和氨基酸的种类对MR的褐变强度有很大影响,其影响程度由强到弱分别为:Xly>Glc,Lys>Gly>Glu>Cys。随着反应时间的延长,各体系MRPs的褐变程度逐渐变强;而荧光吸收强度随着加热时间的延长而增强,然后在出现最大值后趋于平缓或者表现出下降的趋势。MRPs的抗氧化能力也随反应时间的延长而增强,抗氧化活性与褐变强度呈正相关,与荧光吸收特性没有表现出明显的关联。     

L-赖氨酸与葡萄糖美拉德反应及其产物的抗氧化性能研究

研究L-赖氧酸与葡萄糖氨基和羰基不同比例的3个体系的美拉德反应(L-赖氨酸的氨基与葡萄糖的羰基的物质量之比分别为1:1、1:2和2:1),并以对超氧阴离子O_2,清除能力为指标,评价了美拉德反应产物(MRPs)的抗氧化能力。结果表明:美拉德反应是个酸度和褐变不断增强的反应;MRPs的最大吸收波长在460 nm左右;达到相同的褐变程度,即吸光度A为2.0时,3个体系的反应速率:1:2>1:1>2:1;不同体系得到的MRPs对O_2~-,都具有较好的清除效果,并且MRPs的抗氧化能力不完全依赖于产物的褐变程度。     

Correlating changes that occur in chemical properties with the generation of antioxidant capacity in different sugar-amino acid Maillard reaction models

Abstract: We investigated the development of antioxidant activity relative to the change of pH, fluorescent intensity, ultraviolet (UV) absorbance (A294), browning (A420), and alpha‐dicarbonyl compounds in sugar‐amino acid Maillard reaction (MR) model systems comprising fructose, glucose, or ribose each with glycine (Fru‐Gly, Glu‐Gly, and Rib‐Gly) or lysine (Fru‐Lys, Glu‐Lys, and Rib‐Lys), respectively, which were heated at 121 °C for 5 to 90 min. For hexose models, the change in pH was shown to fit a second‐order polynomial regression with A294 and A420. Antioxidant activity was significantly and positively correlated with UV absorbance (r = 0.905, P < 0.001) and browning products (r = 0.893, P < 0.001) rather than with fluorescent products or the alpha‐dicarbonyl compounds. Type of sugar was most important in evoking a change in UV absorbance, browning, alpha‐dicarbonyl compounds, and antioxidant activity of MR products (MRPs). In conclusion, the antioxidant activity of MRPs in six model systems was more closely associated with products derived at the intermediate‐to‐late stages of the reaction and influenced mostly by the type of sugar. Practical Application: We report on the different factors and their interactions that are important for understanding the functional attributes of food components that comprise the generation of Maillard browning products and the associated antioxidant activities generated during high‐temperature food processing.     

不同模式体系美拉德反应程度及抗氧化活性比较

以葡萄糖、果糖、蛋氨酸、甘氨酸、精氨酸和大豆分离蛋白为美拉德反应原料,研究加热时间和混合比例对褐变程度的影响,并对褐变程度最强的产物进行抗氧化活性检测。结果表明：葡萄糖、果糖分别与甘氨酸按物质的量之比2:1混合(pH9.0),并于100℃恒温水浴锅中加热180min时褐变程度最强。葡萄糖-甘氨酸与果糖-甘氨酸模式体系的美拉德反应物都具有一定的抗氧化能力。在相同体积分数条件下,果糖-甘氨酸模式体系的美拉德反应物的还原能力和抗氧化值均要强于葡萄糖-甘氨酸模式体系的美拉德反应物。葡萄糖-甘氨酸模式体系的美拉德反应物对 ·OH和O2 ·的抑制率最高分别达50.65%和45.42%,而果糖-甘氨酸模式体系的美拉德反应物对 ·OH和O2 ·的抑制率最高则分别达57.55%和28.54%。     

膜分离鸡骨素酶解液美拉德反应产物的初步研究

本研究对鸡骨素酶解液美拉德反应产物(MRPs)膜分离后的不同组分进行了初步分析。首先鸡骨素酶解液经美拉德反应制得鸡骨素酶解液MRPs,再利用膜分离技术将鸡骨素酶解液MRPs进行微滤、超滤、纳滤和反渗透,从而得到不同分子量范围的鸡骨素酶解液MRPs组分;然后通过吸光度和感官仪器分析,检测了鸡骨素酶解液MRPs各组分的褐变程度、风味色泽变化;通过对还原力、ABTS+自由基清除力、AEC抑制率、氧自由基吸收能力(ORAC)及对环状质粒DNA的保护能力的检测,研究了鸡骨素酶解液MRPs各组分的抗氧化特性,并最终对各组分进行了综合评价。结果表明:鸡骨素酶解液美拉德反应中引起褐变的物质分子量大于3 kDa,反应中间产物的分子量集中在0.3~1 kDa;鸡骨素酶解液经美拉德反应后风味得到改善,抗氧化活性显著提高(p < 0.05),其中呈味物质主要集中在微滤和纳滤组分,鸡骨素酶解液MRPs中各组分与未分离原液相比抗氧化活性有所降低,但都显著高于鸡骨素酶解液(p < 0.05);综合评价显示,鸡骨素酶解液美拉德反应原液的综合得分最高,鸡骨素酶解液MRPs各组分得分也高于鸡骨素和鸡骨素酶解液。     

咸味香精中美拉德反应产物的抗氧化性研究

利用膜分离手段从肉味香基中分离得到不同分子量范围的美拉德反应产物(MRPs),考察咸味香精中的肉味香基以及不同分子量的MRPs对卵磷脂脂质体的抗氧化效果。结果表明,肉味香基对脂质体过氧化有抑制能力,其抗氧化能力随反应物浓度的增加而增强。高分子量MRPs的抗氧化能力最强,其次为中分子量MRPs,小分子量MRPs抗氧化能力最弱,并且MRPs的抗氧化能力与其褐色程度成正比。     

美拉德反应对乳清分离蛋白及其水解物抗氧化性的影响

以乳清分离蛋白及其蛋白水解物为原料分别与半乳糖发生美拉德反应,研究两者美拉德反应的褐变程度、接枝度及产物荧光光谱的变化,同时以乳清分离蛋白和蛋白水解物作对照,研究两者美拉德反应产物的抗氧化性。结果表明:乳清分离蛋白及其水解物美拉德反应的褐变程度、接枝度及产物的抗氧化性均在4 h达到最大。其中,乳清分离蛋白及其水解物与半乳糖美拉德反应的褐变程度和接枝度最大值分别为1.114、18.431%和1.413、28.273%;两者美拉德反应产物的还原力、2,2’-联氨-二(3-乙基-苯并噻唑-6-磺酸)二铵盐自由基清除能力和1,1-二苯基-2-三硝基苯肼自由基清除能力分别为0.605、46.29%、61.77%和0.923、69.81%、78.43%,均显著高于对照组(P0.05)。同时,内源荧光光谱发现,美拉德反应改变了乳清分离蛋白及其水解物的构象,使二者的结构更加松散。     

木糖- 甘氨酸美拉德反应体系光谱特性和抗氧化性能的研究

采用木糖和甘氨酸进行模式美拉德反应,考察反应进程中产物pH值、吸光度及颜色参数的变化,并以1,1-二苯基-2-三硝基苯肼(DPPH)自由基清除能力、Fe2＋螯合能力及油脂过氧化值(POV)为指标,研究美拉德反应产物的抗氧化效果。结果表明：随着反应的进行,产物由无色变为蓝色最后生成褐色;反应pH值和L*值逐渐降低,a*值增大,b*值减小,但后期两者变化不显著。产物具有很好的Fe2＋螯合能力,POV值较低,但清除DPPH自由基能力不强。总体而言,产物具有较强的抗氧化能力。     

木糖与甘氨酸美拉德反应产物抗氧化性能的研究

以木糖和甘氨酸为底物,控制不同的物质的量(木糖与甘氨酸物质的量之比分别为1∶0.1、1∶0.2、1∶0.4)进行美拉德反应,制备了三种不同的美拉德反应产物,并通过还原能力、清除H2O2能力、清除羟基自由基(.OH)、清除超氧阴离子自由基(O2-.)、清除亚硝酸根(NO2-)等体系研究了美拉德反应产物的抗氧化性能。结果表明,三种反应产物均具有较强的抗氧化能力,随着反应产物浓度的增加,抗氧化能力增强;三种产物的还原能力和清除O2-.的能力相当;木糖与甘氨酸物质的量之比为1∶0.2的美拉德反应产物清除H2O2、.OH和NO2-的能力要强于物质的量之比为1∶0.1和1∶0.4的反应产物。     

Characteristics and antioxidant activity of ultrafiltrated Maillard reaction products from a casein–glucose model system

Maillard reaction products (MRPs) were prepared from casein–glucose by refluxing for 130 min at 102 °C and initial pH 12.0 without pH control to investigate the characteristics of casein–glucose Maillard reaction and the antioxidant activity difference among different fractions of MRPs. Browning and intermediate products increased, however, the pH of the system decreased with increase in the heating time. Free amino group content decreased 78% during first 10 min and did not change nearly thereafter. Amino acid analysis indicated that lysine and arginine decreased significantly, and casein was partially hydrolysed to peptides or free amino acid. High molecular weight compounds were dominant in the MRPs, determined by high performance gel-filtration chromatography. After ultrafiltration, antioxidant activity of each MRPs fraction was investigated by DPPH radical-scavenging activity, reducing power, Fe²⁺ chelating activity and lecithin oxidation assay. MRPs of different molecular weight exhibited distinctly different antioxidant activities.     

美拉德反应修饰的鲢鱼肽抗氧化活性初探

美拉德反应修饰是改善肽抗氧化活性的新途径。本实验采用鲢鱼肽与葡萄糖作为反应原料,以不同的浓度反应0,2,4,6,8,10h,并分别对棕色变化、还原糖、游离氨基、还原力和DPPH自由基清除活性进行了测定,结果表明美拉德反应产物均表现出很好的抗氧化活性,还原力在一定的范围内随时间的增加而增强,E组(10g鲢鱼肽和5g葡萄糖)最大,在10h时为A组的6.09倍。清除DPPH自由基的活性则在2h时达到较高的值,E组具有最高的的自由基清除率为64.45%。美拉德反应产物的还原力与DPPH自由基清除活性不一致,而且其抗氧化能力不完全依赖于产物的褐变程度。     

赖氨酸—木糖体系美拉德反应产物的优化制备及抑菌性

以木糖(Xylose)和赖氨酸(Lys)为原料,以美拉德反应褐变水平和美拉德反应产物(MRPs)的抗氧化力活性(通过FRAP值表征)为评价指标,结合响应面法优化并得到木糖—赖氨酸体系美拉德反应产物(XL-MRPs)的最佳制备条件,并对其抑菌性进行研究。结果表明,XL-MRPs的最佳制备条件为:反应时间120min,pH 9.0,反应温度109℃,木糖与赖氨摩尔比2.1∶1.0,该条件下XL-MRPs的抗氧化性最强,FRAP值为1.33±0.16。XL-MRPs对金黄色葡萄球菌、大肠杆菌和枯草芽孢杆菌均具有抑菌作用,且XL-MRPs溶液的最小抑菌浓度为10-6。     

微波加热缬氨酸和葡萄糖的棕化反应

研究了微波加热下pH值、反应时间、溶剂配比对缬氨酸与葡萄糖的棕化产物反应深度的影响,以及微波加热和普通加热的棕化产物的差异,并进行了棕化产物的卷烟加香试验及其醚溶性成分的分析。结果表明:①微波能加速棕化反应进程,在相同反应时间内微波反应产物的一些主要成分含量要大于普通加热产物;②温度对棕化反应影响大于加热方式;③相同体系,普通加热和微波加热棕化产物成分基本相同,只是在含量上有差别;④体系的pH值对微波棕化反应进程及反应产物都有较大影响,酸性和碱性环境都能加速反应进程;⑤微波加热的缬氨酸与葡萄糖产物中共鉴定出5种重要的吡嗪类化合物和1种呋喃类化合物,没有鉴定出醛类、吡咯类等常见的普通棕化反应产物;⑥在微波加热,pH6·35,反应时间30min,溶剂为丙二醇-水(1∶1体积比)条件下,缬氨酸与葡萄糖的棕化反应产物加香效果较好。