Abstract:

Objective: The contents of total polysaccharides, total phenols, total flavonoids and different configurations
of vitamin E and antioxidant activity were considered as indicators to select a suitable drying method for Euryale
Semen. Methods: Ultraviolet (UV) spectroscopy was applied to determine antioxidant activity and the contents of total
polysaccharides, total phenols and total flavonoids and different configuration of vitamin E were quantified by high
performance liquid chromatography (HPLC). The effects of six different drying methods including shade drying, sun
drying, cabinet drying, vacuum-freeze drying, infrared drying and microwave drying on the quality of Euryale Semen
were evaluated. Results: Microwave drying could largely retain total polysaccharides, total phenols and total flavonoids in
samples. But the highest contents of different configuration of vitamin E were accumulated and the ability to scavenge DPPH
free radicals and ABTS+· was the strongest in vacuum freeze-dried samples. Meanwhile, a significant correlation existed
between vitamin E and antioxidant activity. Conclusion: Vacuum freeze drying can be regarded as a suitable method for
processing Euryale Semen because it not only can largely accumulate the content of vitamin E to result in the best antioxidant
activity, but also can reduce the loss of total polysaccharides, total phenols and total flavonoids to the largest extent.

Key words: drying method, Euryale Semen, functional component, antioxidant activity