Determination of contents and components of water-soluble sugar in watermelon fruit by HPLC-ELSD

【Objective 】The components and contents of water-soluble sugar in watermelon fruit were studied using HPLC- ELSD to provide references for accurate identification of watermelon germplasms and quality watermelon breeding. 【Method 】The components and contents of water-soluble sugars in watermelon fruit were analyzed by HPLCELSD. The working condition of HPLC was Comosil Sugar-D column(4.6 mm ID ×250.0 mm),acetonitrile and water with a volume ratio of 75 ∶25 as mobile phase, flow rate of 1.0 m L/min and column temperature of 30 ℃. ELSD parameters were detector drift tube temperature of 80℃ and gas flow rate of 1.60 m L/min. 【Result 】The contents of glucose,fructose and sucrose could be precisely measured in 10 minutes. The linear relation of fructose(r =0.9943),glucose(r=0.9997) and sucrose(r=0.9988) was good in the range of 0.25-3.00 mg. The recovery of sample ranged from 98.57% to 101.36%. The contents of fructose, glucose and sucrose in watermelon fruit were 45.88,16.62 and34.03 mg / g, respectively. 【 Conclusion 】 The method of HPLC- ELSD possesses advantages of easy operation, high accuracy and good reproducibility, and it can be applied as a quick measurement of the contents of glucose, fructose and sucrose in watermelon fruit.