Changes in lipids and medium- and long-chain fatty acids during the spontaneous fermentation of ripened pu-erh tea oleh Qiu-yue Chen, Ming-li Liu, Ruo-yu Li, Bin Jiang, Kun-yi Liu, Yan-qin Xiao, Qi Wang, Teng Wang, Lian-qin Zhao, Wei-tao Wang, Zhi-wei Liu, Li-jiao Chen, Yan Ma, Ming Zhao