Simultaneous quantification of free amino acids and 5′-nucleotides in shiitake mushrooms by stable isotope labeling-LC-MS/MS analysis

• Published in: Food chemistry 2018-12, Vol.268 (C), p.57-65
• Main Authors: Dong, Meng, Qin, Lei, Xue, Jia, Du, Ming, Lin, Song-Yi, Xu, Xian-Bing, Zhu, Bei-Wei
• Format: Article
• Language: English
• Subjects: 5′-Nucleotides; Free amino acids; PCA; Shiitake mushrooms; SIL-LC-MS/MS
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2018.06.054

•A method for simultaneous quantitation of FAAs and 5′-nucleotides in mushrooms is described.•The method was validated and showed good quantification accuracy, precision, and recovery.•Ten species of shiitake mushrooms could be discriminated by the contents of FAAs and 5′-nucleotides. Evaluation of free amino acids (FAAs) and nucleotides in various food matrices has been a widely studied topic in recent years. Here, a fast and efficient strategy for the simultaneous analysis of 20 FAAs and six 5′-nucleotides, using stable isotope labeling-liquid chromatography coupled with tandem mass spectrometry (SIL-LC-MS/MS) is proposed. The method was validated with respect to selectivity, linearity, limits of detection (LOD) and quantification (LOQ), recovery, precision, and stability. LOQs of most FFAs were lower than 1 ng/mL, and 5′-nucleotides were in the range of 5–20 ng/mL. FAAs and 5′-nucleotides in ten shiitake mushrooms from different cultivate areas were further analyzed. Results showed that the contents of cytidine 5′-monophosphate, adenosine 5′-monophosphate, lysine, threonine, arginine were significantly different. Principal component analysis showed clear discrimination of origins, seasons and species. Thus, the proposed method is suitable for the fast discrimination of species and geographical origins of shiitake mushrooms.