Institute of Nutritional and Food Sciences, Molecular Food Technology, University of Bonn, Römerstrasse 164, D-53117 Bonn, Germany.
Food Res Int. 2018 Jul;109:426-432. doi: 10.1016/j.foodres.2018.04.052. Epub 2018 Apr 25.
Hydroxycinnamic acids are a major group of phenolic compounds widely distributed in plants. Among them, chlorogenic acids and caffeic acid have been in the focus of interest due to their impact on food quality and their putative health benefits. Numerous microorganisms like lactic acid bacteria are able to hydrolyze chlorogenic acids by cinnamoyl esterase enzymes. Data on the specificity of theses enzymes regarding the cleavage of distinct isomers of mono- or dichlorogenic acids is lacking. Lactobacillus reuteri, Lactobacillus helveticus, and Lactobacillus fermentum were screened for their ability to hydrolyze chlorogenic acid isomers in culture medium. Concentrations of chlorogenic acids and the released caffeic acid were determined by UHPLC-ESI-MS. The highest hydrolysis rate (100%) was observed for the hydrolysis of 5-CQA by Lactobacillus helveticus. A so far unknown metabolic pathway for the cleavage of 4-CQA is proposed including isomerization to 5-CQA and 3-CQA followed by hydrolysis.
羟基肉桂酸是广泛存在于植物中的一类主要的酚类化合物。其中，绿原酸和咖啡酸因其对食品质量的影响及其潜在的健康益处而受到关注。许多微生物，如乳酸菌，能够通过肉桂酰酯酶水解绿原酸。关于这些酶对单或二咖啡酰基绿原酸不同异构体的切割特异性的数据尚缺乏。本研究筛选了瑞士乳杆菌、德氏乳杆菌和发酵乳杆菌是否能够在培养基中水解绿原酸异构体。通过 UHPLC-ESI-MS 测定绿原酸及其释放的咖啡酸的浓度。瑞士乳杆菌对 5-CQA 的水解率最高（100%）。提出了一个目前未知的 4-CQA 裂解代谢途径，包括异构化为 5-CQA 和 3-CQA，然后水解。
