Abstract:

The ultrasonic-assisted extraction of polysaccharides from seed cake of Camellia oleifera Abel was investigated.
An orthogonal array design was used to establish the optimum extraction conditions. Total sugar content was determined by
phenol-sulfuric acid method and monosaccharide composition was analyzed by HPLC following pre-column derivatization.
Besides, the antioxidant activity of polysaccharides from seed cake of Camellia oleifera Abel was assessed. The results showed
that the optimum extraction conditions of ultrasonic output power, temperature, time and solid-to-solvent ratio were 150 W, 80 ℃,
45 min and 1:15 (g/mL), respectively. Under these conditions, the extraction yield of polysaccharides was (14.22 ± 0.51)%.
The extracted polysaccharides consisted mostly of glucose Glu, Rha and Man along with a small amount of GalUA, Gal, Xyl
andAra and showed a total sugar content of 81.2%. Antioxidant experiments showed that the free radical scavenging activity
of the polysaccharides against hydroxyl and DPPH radicals was concentration dependent, with scavenging rates of 84.6% and
73.5% at 5 mg/mL, respectively. Nevertheless, almost no reducing power activity was observed.

Key words: polysaccharides from seed cake of Camellia oleifera Abel, ultrasonic-assisted extraction, orthogonal array design, monosaccharide composition, antioxidant activity