温和条件下的美拉德反应对干腌肉品风味的贡献

为了研究干腌肉制品风味形成机理,建立了核糖与氨基酸(Leu,Ile,Val,Met)在温和(微酸性pH及非加热)条件下的美拉德反应模型.经过SPME-GC/MS检测,表明产生的主要挥发性产物分别是3-甲基丁醛、2-甲基丁醛、2-丁酮、2-甲基-2-丁烯醛、2-甲基丙醛、二甲基二硫化物、3-甲基硫代丙醛,以上挥发性化合物已在一些不同的干腌火腿中检测到.     

大豆肽的美拉德反应产物在鸡汤中的应用

采用超滤技术对大豆肽进行初步分离,制备的分子量分布1000~5000u含量不同的五种大豆肽(SP1、SP2、SP3、SP4、SP5)分别与木糖在120℃反应120min,考查各大豆肽美拉德反应产物(MRPs)在鸡汤中的应用效果。结果表明,各大豆肽的MRPs显著增强了鸡汤的鲜味、醇厚味和持续感,但对鸡汤香气没有明显的改善。SP4和SP5的MRPs适用于高品质风味料的制备,SP2和SP3体系产物适用于大规模开发成本低廉且具有良好风味增强效果的风味料。      

基于烟草水提物的Maillard反应产物影响因素

为充分利用烟叶资源,提高其使用价值,以亚临界萃取后的烟叶残渣为原料制备了烟草水提物,利用GC-MS法对Maillard反应产物进行定量分析,系统探讨了氨基酸种类及用量、反应时间对Maillard反应产物化学组成及卷烟感官质量的影响;并探讨了Maillard反应产物中的18种成分与卷烟感官指标的相关关系。结果表明:①谷氨酸和天冬氨酸的Maillard反应产物与水提物自身的Maillard反应相似,以5-羟甲基糠醛为主,其次为羟基丙酮、2-乙酰基吡咯;脯氨酸参与的反应产物则以羟基丙酮、糠醇和5-羟甲基糠醛为主。②以感官作用为依据,基于烟草水提物Maillard反应的最佳条件为还原糖（以葡萄糖计）与谷氨酸的摩尔比n_还原糖:n_谷氨酸=1:0.5、反应温度110 ℃、反应时间2 h。③18种成分中,2-甲基四氢呋喃-3-酮与烟气浓度相关关系密切,糠醛、5-甲基糠醛、2-呋喃基羟基甲基酮和5-羟甲基糠醛与透发性关系密切,羟基丙酮和3-甲基-1, 2-环戊二酮与烘焙香关系密切。      

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。      

Characteristics and antioxidant activity of Maillard reaction products from fructose-glycine oligomer

The pH of Maillard reaction products (MRPs) derived from the Gly model system (Gly) decreased markedly as heating time increased. However the Digly model system (Digly) exhibited the highest increase in absorbance at 294 and 420 nm. Moreover, the loss of fructose and degree of sugar enolization in MRPs derived from the Trigly model system (Trigly) was the highest, whereas the glycine oligomer content in the Digly noticeably decreased as heating time increased. Furthermore, the gel permeation chromatograms (GPC) patterns of all MRP samples exhibited rising intensities as a function of the heating time, whereas the major peaks of each MRP sample were eluted at different retention times as glycine oligomer. Antioxidant activity of each MRP sample was investigated by Fe²⁺ and Cu²⁺ chelating activity, Trolox, ABTS, 1,1-diphenyl-2-picryl-hydrazil (DPPH) radical scavenging activity, and ferric reducing ability of plasma (FRAP) assay. MRPs derived from the glycine oligomer were found to be effective antioxidants in different antioxidant activity assays.     

抗氧化作用的精氨酸-木糖美拉德反应产物的制备条件

用精氨酸和木糖通过美拉德反应可制备具有抗氧化活性的产物。调查了反应时间、起始pH和反应物摩尔比对产物的抗氧化性能的影响。最佳反应条件是:1mol/L的精氨酸与1mol/L的木糖水溶液在pH起始值为5时反应回流10h。如在1∶1吡啶/水介质中反应产物的抗氧化性可提高二倍。     

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。     

Antioxidant activity of water-soluble Maillard reaction products

Maillard reaction products (MRP) results from a condensation reaction between amino acids (or proteins) and reducing sugars or lipid oxidation products, and MRP exhibit in vitro antioxidant activities. The objective of this study was to determine antioxidant activities of water-soluble MRP from the reaction between histidine (His) and glucose (Glu) by using the oxygen radical absorbing capacity (ORAC_PE) assay with phycoerythrine. Heating His–Glu mixture at 100 °C up to 30 min did not generate MRP with antioxidant activity. However, significant formation of MRP with ORAC_PE values of 0.25, 0.43, and 0.44 μmol Trolox equivalent/mg reaction mixture was observed when the mixture was heated at 120 °C for 10, 20, and 30 min, respectively. Heating the mixture at 120 °C over 30 min reduced the peroxyl radical scavenging activity of the MRP, possibly due to the degradation of antioxidant MRP formed in the earlier stages of the reaction. In conclusion, MRP obtained from His–Glu mixture possesses peroxyl radical scavenging activity, and this activity can be quantified by the ORAC_PE assay.     

美拉德反应产物的抗突变作用

美拉德反应是食品制备、加工和贮存过程中发生的非酶褐变反应，褐变的发生对产品质量有很大影响，从食品卫生学的角度来看，有些产物对人体健康有极大的危害。本文讨论的是美拉德反应产物有益的一面，即其抗突变的效果。     

磷脂酰乙醇胺-还原糖美拉德产物的制备及抗氧化活性研究

为研究亚麻籽炒籽过程中形成的美拉德产物(MRPs)以及提高低温压榨亚麻籽油的氧化稳定性,将3种还原糖(葡萄糖、果糖和木糖)与磷脂酰乙醇胺(PE)进行模拟反应,探究反应温度、反应时间和底物物质的量比对MRPs抗氧化活性的影响,利用质谱分析MRPs的主要成分,并考察MRPs对低温压榨亚麻籽油氧化稳定性和醛类化合物形成的影响。结果表明：PE-木糖体系的MRPs具有最高的体外抗氧化能力,其最适反应条件为PE与木糖物质的量比1∶1、反应温度160℃、反应时间60 min,在该条件下MRPs (2 mg/mL)DPPH自由基清除率达79.57%,铁离子还原抗氧化能力(FRAP)为43.65μmol/g,铁离子螯合能力为13.34%;通过质谱分析发现由一分子木糖和一分子PE反应形成的PE-吡咯-2-甲醛为MRPs中的主要成分;在190℃加速氧化实验中,PE-木糖体系的MRPs对低温压榨亚麻籽油过氧化值和p-茴香胺值的增长表现出与TBHQ相似的抑制作用,同时核磁共振氢谱分析结果表明MRPs可以减缓单烯醛和二烯醛的生成。综上,MRPs可以有效提高油脂的氧化稳定性。     

乳清蛋白肽美拉德反应产物的制备及其抗氧化特性的评价

以乳杆菌A-2发酵乳清蛋白与乳糖发生美拉德反应,制备得乳清蛋白肽美拉德反应产物,对其进行分离纯化并研究抗氧化活性。将乳杆菌A-2接种于复原乳清粉培养基经热加工得发酵产物,经Sephadex G 15层析柱分离,采用SDS-PAGE图谱证实乳杆菌A-2发酵乳清粉在干热处理条件下确实发生了美拉德反应;以抗坏血酸(维生素C)和丁基羟基茴香醚(BHA)为阳性对照,用ABTS法和ORAC法来测定和评价乳杆菌9029乳清蛋白发酵产物的抗氧化作用。在反应体系中,H-DPWF-1、BHA和维生素C的ABTS清除率分别是77.38%、86.47%和73.95%,H-DPWF-1清除ABTS自由基的能力的介于维生素C和BHA之间;样品H-DPWF-1的相对ORAC值为3.43mmol TE/g,维生素C的相对ORAC值为9.67mol TE/g,即H-DPWF-1清除AAPH的能力为维生素C的1/3。结果显示H-DPWF-1具有较强的抗氧化活性,具有广阔应用前景和潜力。     

Optimization of Maillard reaction products from casein-glucose using response surface methodology

Response surface methodology (RSM) was applied to optimize the processing parameters of casein-glucose Maillard reaction for improving the emulsifying ability and antioxidant activity. The effect of heating time, temperature and initial pH on Maillard reaction products (MRPs) was evaluated. Emulsifying ability and reducing power were taken as response values. An increase of temperature in range and initial pH were associated with an enhanced emulsifying ability and reducing power of the MRPs. Substrate concentration 20%, casein-glucose ratio 1:2, heating time 132.7 min, temperature 100.2 °C and initial pH 12.0 were optimum conditions for the improved emulsifying ability and antioxidant activity of the MRPs. The predicated results for optimum reaction conditions coincided well with experiments values.     

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。     

Antioxidant activity of Maillard reaction products from a Yak casein-glucose model system

Maillard reaction products (MRPs) were prepared by reacting both Yak and Holstein casein with different ratios of glucose to casein from 0:1 to 2.5:1. The results showed that the content of intermediate products and browning intensity of the Yak casein-glucose system increased with increasing concentrations of glucose, but were lower than for the Holstein system at the same ratio. With glycosylation, the reducing power and the 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity of both Yak and Holstein caseins were enhanced. With increased glucose content, the reducing power of Yak MRPs increased at the same concentration. The metal chelating activity of Holstein MRPs decreased or was eliminated in the ratio range of 0.5:1 to 2.0:1 g glucose g⁻¹ casein, while that of Yak MRPs were reduced in general. Improvement of the inhibitory activity for Yak casein was lower than that of Holstein casein after glycosylation by glucose.     

Characteristics and antioxidant activity of Maillard reaction products from psicose-lysine and fructose-lysine model systems

D-Psicose, an epimer of D-fructose isomerized at C-3 position, is a rare ketohexose that is thought to be beneficial for obese people and diabetic patients as a noncaloric sweetener. In the present study, model Maillard reaction products were obtained from D-psicose (or D-fructose) and L-lysine heating at 120 °C up to 8 h with the initial pH 9.0. The changes in pH, UV-vis absorbance, and free amino groups during the reaction were detected. Moreover, the antioxidant potential of the Maillard reaction products at different intervals was investigated. Although there was almost no difference in the oxygen radical absorbance capacity, the Maillard reaction products from psicose performed better than that from fructose in the radical-scavenging activity of 2, 2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt and 1, 1,-diphenyl-2-picryl-hydrazyl. The reducing power of the Maillard reaction products from psicose was also stronger than that from fructose. These results indicated that psicose played an effective role in the Maillard reaction and its Maillard reaction products could act as potential antioxidants in food industry.     

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。     

乳制品中的Maillard反应标示物及其应用

乳制品中的Maillard反应标示物既可作为乳制品热处理程度的指标，还可用于不同热处理乳制品的鉴别。介绍了在评价乳制品热处理程度以及区分不同乳制品中常用的几种Maillard反应标示物。这些标示物包括糠氨酸、乳果糖、糠醛类化合物、荧光化合物等。此外，还介绍了可溶性乳清蛋白、碱性磷酸酶和乳过氧化物酶等热处理标示物，这些标示物与Maillard反应之间具有较好的相关性，也是评价乳制品热处理程度以及区分不同乳制品时常用的指标，可与Maillard反应标示物联合应用。     

Isolation and identification of an antiproliferative substance from fructose–tyrosine Maillard reaction products

We isolated a substance from fructose–tyrosine Maillard reaction products (MRPs) and investigated its antiproliferative effect on six human cancer cell lines. The ethyl acetate fraction of fructose–tyrosine MRPs showed a strong antiproliferative effect; this fraction was isolated and purified using silica gel column chromatography, semipreparative RP-HPLC, and recycling HPLC. The structure of the purified compound was determined using spectroscopic methods. The isolated compound was identified as 2,4-bis(p-hydroxyphenyl)-2-butenal (C₁₆H₁₄O₃, HPB242). HPB242 inhibited cell growth in a dose-dependent manner (10–80 μg/ml) on the six human cancer cell lines. The IC₅₀ values of HPB242 on the six human cancer cell lines were 17.34 μg/ml (MCF-7), 29.21 μg/ml (HCT-116), 34.57 μg/ml (H-460), 34.87 μg/ml (HepG2), 48.77 μg/ml (PC-3), and 55.83 μg/ml (MKN-45).     

梅拉德反应产物在白肋烟处理中的应用

利用不同的氨基酸与葡萄糖进行梅拉德反应,用多种氨基酸混合后与葡萄糖进行梅拉德反应.反应结果显示,用多种氨基酸的混合物与糖反应产物用于白肋烟处理好于单一氨基酸的反应产物.以合适的反应产物为基础料研制开发出的白肋烟专用香精,对提高白肋烟的特征香气、掩盖杂气、减轻刺激、改善余味有较明显的作用.