In this study, a high-performance liquid chromatography (HPLC) method was adapted to measure the γ-aminobutyric acid (GABA) and glutamate (Glu) content in different fermented foods. The best solvent to extract GABA and Glu from the food matrices was 75% EtOH and water, combined with 4% SSA as posttreatment. The extracted amino acids were derivatized with o-phthalaldehyde (OPA) for 2 min at room temperature and analyzed by HPLC with fluorescence detector (λex = 340 nm and λem = 455 nm). Animal-based fermented products had a higher GABA content, compared with plant-based and soy-based fermented products. Among 17 fermented samples, fish sauce showed the highest amount of GABA (16.29 ± 0.53 mg/kg DW). Results obtained by the HPLC method were compared with those obtained by a spectrophotometric method, which is based on the reaction of ω-amino acids with phenol. All measured GABA contents, obtained by HPLC method, were much lower than those obtained by the spectrophotometric method, which was due to the nonspecific reaction of the coloring reagent with other amino acids than GABA. It can be concluded that GABA content in food products can only be measured by HPLC.

在这项研究中，采用高效液相色谱（HPLC）方法来测量不同发酵食品中的γ-氨基丁酸（GABA）和谷氨酸（Glu）含量。从食品基质中提取GABA和Glu的最佳溶剂是75％的乙醇和水，再加上4％的SSA作为后处理。提取的氨基酸在室温下用邻苯二甲醛（OPA）衍生化2分钟，并通过带有荧光检测器（λex= 340 nm和λem= 455 nm）的HPLC分析。与植物基和大豆基发酵产品相比，动物基发酵产品的GABA含量更高。在17个发酵样品中，鱼露的GABA含量最高（16.29±0.53 mg / kg DW）。将通过HPLC方法获得的结果与通过分光光度法获得的结果进行比较，这是基于ω-氨基酸与苯酚的反应。HPLC法测得的所有GABA含量均比分光光度法测得的低得多，这是由于着色剂与GABA以外的其他氨基酸发生了非特异性反应。可以得出结论，食品中GABA的含量只能通过HPLC测定。