摘要
探讨氨基酸对广泛存在于食品和人体中丙酮醛和甲醛的消除作用及其机制。将氨基酸与丙酮醛按物质的量比1∶1加入pH 7.0的蒸馏水中,80℃反应4 h,对丙酮醛衍生后测定其残留量,研究不同氨基酸对丙酮醛的消除作用,发现半胱氨酸、γ-氨基丁酸、赖氨酸有较高的清除能力。然后,以食品中含量较高的γ-氨基丁酸为对象,在甲醛存在的模拟胃肠条件下,研究其对丙酮醛消除的影响,发现γ-氨基丁酸在pH 7.0体系中对丙酮醛的消除率更高,且甲醛的添加促进了γ-氨基丁酸对丙酮醛的消除,消除率达81%。同时发现在热加工条件下(160℃)甲醛也大幅促进了丙酮醛的消除。在此基础上,制备并分离纯化γ-氨基丁酸与丙酮醛和甲醛的反应产物。经高效液相色谱-串联质谱、高分辨质谱和核磁共振波谱鉴定,该产物的相对分子质量为254.1339,最大吸收波长为220 nm,其结构为2分子γ-氨基丁酸与1分子甲醛和1分子丙酮醛通过亲核加成反应后形成的一个含氮五元环化合物,属于咪唑盐类。
Methylglyoxal and formaldehyde are harmful substances widely existing in foods and in the human body.This work aimed to evaluate the efficacy and mechanism of action of amino acids in eliminate them.At pH 7.0,different amino acids were reacted with methylglyoxal with a molar ratio of 1:1 at 80℃for 4 h,and residual methylglyoxal was determined using high performance liquid chromatography(HPLC)after derivatization.Among the 14 amino acids investigated,cysteine,γ-aminobutyric acid,and lysine showed the highest ability to eliminate methylglyoxal.γ-Aminobutyric acid,more abundant in foods,was found to be more effective in eliminating methylglyoxal at pH 7.0 than pH 2.0,and the presence of formaldehyde increased the elimination rate to 81%.This effect was more pronounced under thermal conditions(160℃).Based on the above results,the reaction product ofγ-aminobutyric acid with methylglyoxal and formaldehyde was synthetized and purified.By high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS),high-resolution mass spectrometry(HRMS),and nuclear magnetic resonance(NMR),the product was identified as an imidazole salt with a molecular mass of 254.1339 and a maximum absorption wavelength of 220 nm.It was a nitrogen-containing pentabasic cyclic product formed from two molecules ofγ-aminobutyric acid,one molecule of methylglyoxal and one molecule of formaldehyde through nucleophilic addition.
作者
胡嘉漫
黄才欢
郑洁
欧仕益
李瑞阳
欧隽滢
HU Jiaman;HUANG Caihuan;ZHENG Jie;OU Shiyi;LI Ruiyang;OU Juanying(College of Science and Engineering,Jinan University,Guangzhou 510632,China;Guangdong-Hong Kong Joint Innovation Platform for the Safety of Bakery Products,Guangzhou 510632,China;Institute of Food Safety and Nutrition,Jinan University,Guangzhou 510632,China)
出处
《食品科学》
EI
CAS
CSCD
北大核心
2022年第4期32-38,共7页
Food Science
基金
广东省自然科学基金项目(2018A030313064)
中国博士后科学基金项目(2020M673077)
中央高校基本科研业务费专项(21620327)。
关键词
丙酮醛
甲醛
氨基酸
Γ-氨基丁酸
加合物
methylglyoxal
formaldehyde
amino acid
γ-aminobutyric acid
adduct
