Optimization of Extraction Process of Crude Polysaccharide from Siraitia grosvenorii and Development of Pressed Candy

Taking Siraitia grosvenorii as experiment material, crude polysaccharide was extracted by water-extraction alcohol-precipitation method assisted with cellulase. Single factor experiments were conducted to analyze the effect of digestion pH, cellulase dosage, digestion time, and digestion temperature on the crude polysaccharide yield. Based on the results of the single experiments, response surface method was applied to optimize the extraction process. The optimized extraction process of crude polysaccharide from Siraitia grosvenorii was as follows: Digestion pH5.9, cellulase dosage 0.8%, digestion temperature 50 ℃, digestion time 62 min. Under the above extraction process, the crude polysaccharide yield was 6.64%, which was consistent with the model predicted value. Based on the anti-inflammatory and antioxidant value of Siraitia grosvenorii, a kind of pressed candy was developed. The influence of the different addition of crude polysaccharide, magnesium stearate, aspartame and mannitol on the sensory quality of the Siraitia grosvenorii pressed candy by single factor experiment. Subsequently, the formula of the pressed candy was further optimized by orthogonal experiment. The results showed that the optimized formula of the pressed candy was as follows: Siraitia grosvenorii crude polysaccharide 20%, magnesium stearate 1.5%, aspartame 3%, and mannitol 60%. The sensory score of the pressed candy under the optimized formula was 90 and the candy was of uniform color, cool taste, and no sand sense.