Determination of glutathione in ready-to-eat edible bird's nest using a novel LC-MS method

Glutathione (GSH) is a strong antioxidant. However, there was no method to determine the GSH in ready-to-eat edible bird's nest (EBN). A liquid chromatography-mass spectrometry (LC-MS) method was developed for the determination of GSH in ready-to-eat EBN in this study. The method involves extraction by formic acid and methanol, vortex, ultra sonication and analysis using HPLC-MS/MS. The results showed that the linearity was good in the concentration range of 0.05–200 μg/L. The limit of detection and the limit of quantification of the method were 0.1 μg/kg and 1.0 μg/kg. In addition, the recovery was 90.6∼100.4% and the relative standard deviation was 1.2∼2.5%. Moreover, the content of GSH in ready-to-eat EBN produced by different stewing treatment was investigated. It was found that the content of GSH in ready-to-eat EBN increased with the increasing stewing time and temperature. When the stewing temperature was above 110 °C and the stewing time was above 15 min, it was more conducive to the formation of GSH in ready-to-eat EBN. In conclusion, this study provided a new method for the determination of GSH in ready-to-eat EBN, and also opened up a new direction for exploring the nutritional value of ready-to-eat EBN.