Abstract:

Objective: To develop a simple, accurate and sensitive method for determination of fructose, glucose, sucrose, maltose and lactose in pumpkin. Methods: The sugars in pumpkin were extracted with hot water, separated on Kromasil NH2 column (250 mm × 4.6 mm, 5 μm) using acetonitrile and water (80:20, V/V) as the mobile phase, and examined using an evaporative light scattering detector. Results: The linear ranges of fructose and glucose, sucrose, were maltose and lactose 0.5 to 3 g/L, 0.75 to 5 g/L, 0.5 to 5 g/L, 1 to 10 g/L and 1 to 10 g/L respectively. Their detection limits were 1.90, 2.40, 1.80, 2.50 and 2.60 μg/L, respectively. The average spike recoveries were 99.0%, 97.1%, 98.9%, 99.5% and 102.4%, respectively, and the relative standard deviations were 1.02%, 1.41%, 1.27%, respectively. The determination results of fructose, glucose and sucrose in five saled pumpkin samples were 1.05% to 3.80%, 0.823% to 4.49%, and 0.090% to 5.19%, respectively, while no maltose and lactose were found in these pumpkin samples. Conclusion: This method is simple, fast and accurate, and can be applied to the determination of fructose, glucose and sucrose in pumpkin with satisfactory results.

Key words: high performance liquid chromatography-evaporative light scattering detection (HPLC-ELSD), pumpkin, fructose, glucose, sucrose