Comparative evaluation of flavor-related chemical compounds of 'Feizixiao' litchi from various regions using E-tongue, E-nose, and HS-SPME-GC-MS.

'Feizixiao' (FZX) is the most widely cultivated litchi variety in China. However, the evaluation of quality attributes of FZX remains limited. The flavor-related compounds of FZX from three producing regions were characterized using HPLC, E-tongue, E-nose, and combined with HS-SPME-GC-MS. The results indicated that amino acids were abundant, with the highest level of GABA found in all three FZXs. E-tongue and E-nose effectively distinguished the three FZXs. HS-SPME-GC-MS combined with OPLS-DA identified 24 characteristic volatiles of FZX, including geraniol, citronellol, linalool, rose ether, phenylethyl alcohol, and 1-octen-3-ol. Correlation analysis revealed that Hainan's FZX, which grows at lower altitudes, has a milder volatile profile and fewer volatiles. Guangdong's FZX showed higher contents of sugars, acids, and volatiles. Yunnan's FZX, located at high altitudes, was abundant in sugars, acids, and amino acids, exhibiting a unique flavor profile. This study offers valuable insights into identifying the origin of litchi and evaluating its quality.