1. Citrus Research Institute, Southwest University, National Citrus Engineering Research Center, Chongqing 400712, China
2. College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China
3. Chongqing Institute for Food and Drug Control, Key Laboratory of Condiment Supervision Technology for State Market Regulation, Chongqing 401121, P. R. China