Optimization of Ultrasonic-assisted Extraction of Polysaccharides from Ottelia Acuminate (Gagnep.) Dandy using RSM

Ultrasonic technology was applied to polysaccharides extraction from Ottelia acuminata (Gagnep.) Dandy and Response Surface Methodology (RSM) was used to optimize the effects of processing parameters on polysaccharides yields. Three independent variables such as liquid-solid ratio (ml/g, X-1), extraction temperature (degrees C, X-2) and extraction time (hour, X-3) were investigated respectively. The statistical analysis indicated that the three variables and the quadratic of X-1 and X-3 had significant effects on the yields and followed by the significant interaction effects between the variables of X-1 and X-3, X-2 and X-3 (p<0.05). A mathematical model with high determination coefficient was gained. The optimal extraction conditions of polysaccharides were determined as follows: liquid-solid ratio 43 ml/g, extraction temperature 90 degrees C and extraction time 3.45 hours. Under these conditions, the experimental yield of polysaccharides was 107.44 mg/g, which was agreed closely with the predicted value 108.71 mg/g.