The Preparation Of Pumpkin Polysaccharide Slow-release Microcapsules

Pumpkin,an annual herbaceous vine,is rich in a large number of active substances of pumpkin polysaccharide(PP),with hypoglycemic,lowering blood pressure,reducing blood lipid,anti-tumor,enhancing the immunity and other physiological activities.Water-soluble pumpkin polysaccharide,with a strong water-swellable,calorie-free,is not easy to be digested and absorbed by human body,thus prolonging the residence time of the pumpkin polysaccharide in the gastrointestinal tract can reduce food conversion rate and give rise to a sense of satiety.At the same time,it can repair and improve the sensitivity of insulin,improving glucose tolerance,and increasingly become the preferred health products of diabetes patients.In China,diabetes patients reached 114 million people,and it is imminent that the health food based on natural pumpkin polysaccharide must be researched.In this study,the process was optimized which extraction and purification of pumpkin polysaccharide was studied by using the frozen-ultrasonic assisted method.The preparation methods of pumpkin polysaccharide microcapsule were established.The results of this study are as follows:1、Single factor and four factors and three level L9(34)orthogonal experiments were carried out on the extraction conditions of pumpkin polysaccharide extracted by Frozen-ultrasonic method.The optimum extraction process was as follows: ultrasonic power was 560 W,reaction time was 90 min,solid-liquid ratio was 1: 5(W:V),the extraction temperature was 60℃.The extraction rate of pumpkin polysaccharide was13.65mg/g.2、After purification,the powder contained the average content of pumpkin polysaccharide was 83.85%.3、By studying the inhibitory of pumpkin polysaccharide on the α-glucosidase,it was found that with the increase of the volume of pumpkin polysaccharide,the inhibition rate increased slowly,and then remained unchanged.It can be determined that the hypoglycemic effect of pumpkin polysaccharide is not achieved by theinhibition to α-glucosidase,but by other means.4、Microcapsule were Prepared with the wall material: chitosan and sodium alginate.Through single factor and the four factors and three level L9(34)orthogonal experiments,the optimum formula of pumpkin polysaccharide sustained-release microcapsules was: the concentration of sodium alginate was 3.5%,the concentration of CaCl2 was 4%,the concentration of chitosan was 0.2%,and the core wall ratio 1:3.5、The slow-release effect of microcapsules were evaluated by in vitro gastric intestinal juice,Microcapsules after 3h in simulated gastric juice to continue 5.5h in the simulated intestinal fluid,the release rate of around 15.20%,41.31%,respectively.A total of 8.5 hours,the pumpkin polysaccharide total release rate is 56.51%.Microcapsules will continue to release in the intestinal tract for a long time.