National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, China.
Jiangsu Provincial Engineering Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi 214122, Jiangsu, China.
J Agric Food Chem. 2024 Aug 7;72(31):17465-17480. doi: 10.1021/acs.jafc.4c02319. Epub 2024 Jul 24.
Elevated levels of biogenic amines (BAs) in fermented food can have negative effects on both the flavor and health. Mining enzymes that degrade BAs is an effective strategy for controlling their content. The study screened a strain of 1614 from fermented food system that can degrade BAs. The multiple copper oxidase genes were successfully mined after the whole genome protein sequences of homologous strains were clustered and followed by homology modeling. The enzyme molecules can interact with BAs to stabilize composite structures for catalytic degradation, as shown by molecular docking results. Ingeniously, the kinetic data showed that purified LHMCO was less sensitive to the substrate inhibition of tyramine and phenylethylamine. The degradation rates of tyramine and phenylethylamine in (18% vol) after adding LHMCO were 41.35 and 40.21%, respectively. Furthermore, LHMCO demonstrated universality in degrading tyramine and phenylethylamine present in other fermented foods as well. HS-SPME-GC-MS analysis revealed that, except for aldehydes, the addition of enzyme treatment did not significantly alter the levels of major flavor compounds in enzymatically treated fermented foods ( > 0.05). This study presents an enzymatic approach for regulating tyramine and phenylethylamine levels in fermented foods with potential applications both targeted and universal.
发酵食品中生物胺（BAs）水平升高会对风味和健康产生负面影响。挖掘能够降解 BAs 的酶是控制其含量的有效策略。本研究从发酵食品系统中筛选出一株可降解 BAs 的 1614 菌株。对同源菌株的全基因组蛋白序列进行聚类后，进行同源建模，成功挖掘出多种铜氧化酶基因。分子对接结果表明，酶分子可以与 BAs 相互作用，稳定复合结构进行催化降解。巧妙的是，动力学数据表明，纯化的 LHMCO 对酪胺和苯乙胺的底物抑制作用不敏感。添加 LHMCO 后，（18% vol）中酪胺和苯乙胺的降解率分别为 41.35%和 40.21%。此外，LHMCO 还表现出在其他发酵食品中降解其他存在的酪胺和苯乙胺的普遍性。HS-SPME-GC-MS 分析表明，除了醛类，酶处理的添加并没有显著改变酶处理发酵食品中主要风味化合物的水平（ > 0.05）。本研究提出了一种酶法来调节发酵食品中酪胺和苯乙胺的水平，具有靶向和普遍的应用潜力。
