为了探讨不同pH值对美拉德反应产肉香味化合物的影响,文中将硫胺素、半胱氨酸、核糖、木糖组成5个不同的模型体系,用0.2mol/L,pH值分别为4.5、5.0、5.5、6.0、6.5、7.0的磷酸盐缓冲液溶解,125℃反应3h。采用动态顶空制样,结合气相色谱-质谱联用(GC-MS)技术对反应产物中的2-甲基-3-呋喃硫醇、双(2-甲基-3-呋喃基)二硫化物、2-糠硫醇、3-巯基-2-戊酮、壬醛、辛醛进行定量分析。结果发现:硫胺素和半胱氨酸组成的体系在pH=5.5时产生的2-甲基-3-呋喃硫醇最多;含有戊糖的4个反应体系则产生了较多的2-糠硫醇;半胱氨酸和戊糖组成的体系只有在pH≤5.5时才可产生2-甲基-3-呋喃硫醇。5个体系均未检测到双(2-甲基-3-呋喃基)二硫化物和3-巯基-2-戊酮,检测到少量的辛醛和壬醛。

In order to study the effect of the different pH value on the compounds with meat aroma generated in the Maillard reaction,thiamine,cysteine,ribose,xylose were taken to compose five different model systems,the reactants were dissolved in phosphate buffer(0.2 mol/L)at pH 4.5,5.0,5.5,6.0,6.5 or 7.0 and heated at 125℃ for 3 h.Dynamic headspace sampling in combination with gas chromatography-mass spectrometry(GC-MS)was used to analyse the amounts of 2-Methyl-3-furanthiol,bis(2-methyl-3-furyl)disulfide,2-Furfurylthiol,3-Mercapto-2-pentanone,nonanal and octanal.As a result,the model system contained thiamine and cysteine has the highest yields for 2-Methyl-3-furanthiol at pH=5.5,four model systems which contained pentose yield more 2-Furfurylthiol,the reaction between cysteine and ribose yield 2-Methyl-3-furanthiol in the pH≤5.5,All the five model systems were not detected in bis(2-methyl-3-furyl)disulfide and 3-Mercapto-2-pentanone,and only detected small amounts of octanal and nonanal.