Abstract:

This paper describes a reasonable ultrasonic-assisted extraction (UAE) techinque for water-soluble
polysaccharides (WSPs) from Mallotus furetianus tea. Crude polysaccharides were deproteinized by the combined use
of Sevag reagent and protease. The optimum process conditions for enhanced UAE extraction of WSPs were 250 W, 40
min, 60 ℃, 15:1 (mL/g) and 30 min for ultrasonic power, ultrasonication time, temperature, solid/liquid ratio and hot
water extraction time, respectively. Under these conditions, the extraction yield of WSPs was 9.976%. Five extraction
parameters in decreasing order of their importance were ultrasonic power, ultrasonication time, temperature, extraction
time and solid/liquid ratio. The resulting crude extract gave rise to a deproteinization rate of 17.7%. Both Mallotus
furetianus tea and the remaining residue after WSPs extraction contained a small amount of water and showed no obvious
differences in the contents of soluble ash or insoluble ash, with good repeatability. The 15 elements detected in Mallotus
furetianus tea were K, Ca, Mg, Na, S, P, Ba, Mn, Fe, Ni, Zn, Sc, Cu, Cr and Li in the decreasing order of content. The
contents of K, Mg, Na, Mn, Zn, S and P in the WSPs were higher than in the residue, but Ba, Cr, Li, Fe, Cu, Ca, Sc and
Ni were richer in the residue.

Key words: Mallotus furetianus tea polysaccharides, extraction process, element distribution