Extraction Optimization of Polysaccharides from Pitaya Stems

Objective] The aim was to describe the extraction of polysaccharides from pitaya stems.Method] The hot water,enzyme-assisted and microwave-assisted methods were used,with the microwave-assisted extraction being deemed optimal by general evaluation.Result] The main factors affecting the yield of polysaccharides in the microwave-assisted extraction,by order of magnitude,were as follows:time>microwave power>temperature;additionally,optimal conditions included a 10 min extraction time,an 80 ℃ extraction temperature and a microwave setting of 200 W.Using these optimal conditions,the yield of PSPS(Polysaccharides from Pitaya Stems) was 1.42%.After purification,the yield of PSPS was 0.74%.Conclusion] The PSPS was analyzed by IR,MALDI-TOF-MS and an element analysis technique.It was shown to be a polysaccharide mixture,and the molecular weight was between 3 900 and 4 300 Da.