The content of mogroside V as a key indicator of mogrosides was determined by HPLC. HPLC separation was conducted on a Waters Sunfire C18 column (4.6x150 mm, 5um) at 25 C, and the injection volume was 15 ul. The mobile phase consisted of acetonitrile (A) and water (B) at a flow rate of 1.0 ml/min; a gradient separation was programmed as follows : 0 to 40 min, 5 to 68% (A). The elution was monitored at 203 nm.