Research On The Key Technology Of Polysaccharide-enriched Lycium Barbarum Solid Beverage

Polysaccharide-enriched Lycium barbarum L. solid beverage was developed using Lyciumbarbarum L. from Zhongning, Ningxia Province in this paper. The key processingtechnologies, including extraction, clarification and drying were researched, and the factorsthat affect the product’s property such as the polysaccharide content were also studied indetail. An optimum processing conditions to produce polysaccharide-enriched Lyciumbarbarum L solid beverage was obtained..Firstly, the extraction technology of Lycium barbarum L polysaccharide was studied inthis paper. The influence of microwave power, irradiation time and solid to solution ratio onthe yield of polysaccharide were investigated and extracting conditions were optimized byusing RSM (Response Surface Method). The results showed that: the highest yield(3.74%(w/w)) of the polysaccharide was obtained under300W of microwave power for1.8min at1(g):26(mL) of solid to solution ratio, which was23.03%higher than3.04%ofwater-extracted polysaccharide. The antioxidizability of polysaccharide extracted bymicrowave-assistant extraction was close to the polysaccharide yielded by water extraction.The comparison of the main component content’s change before and after clarification bypectinase, chitosan, gelatin and chitosan-gelatin indicated that the vast majority of pectincould be wiped off by pectinase. Chitosan could wiped off segmental pectin and protein, alsowith a bit of polyphenol. Chitosan-gelatin could wiped off more than half of pectin, proteinand polyphenol. Chitosan-gelatin was chosen as the best clarificant after compositecomparation. The influence of different chitosan to gelatin ratio, pH, temperature and time onthe clarification performance were studied. The highest luminousness (91.36%) of theLycium barbarum L. juice was obtained by0.4:1.6of chitosan: gelatin for60min at45℃andpH4.5.16.25times of concentration as the destination of the vacuum concentration process, andthe soluble solid content was65%, with a proper viscosity for the followed operation. A goodcomprehensive quality was observed at1:6(w/w) of malt dextrin-sucrose ratio. Differentdrying methods (hot-air drying, vacuum drying, microwave drying, microwave-vacuumdrying) was used for the sample drying,.The sample dried by microwave-vacuum got the best quality with the shortest drying time, highest polysaccharide preservation. Taking an overallconsideration of drying time, polysaccharide preservation, dissolve time and sensoryevaluation, the quadratic general rotary united experiment was carried out to optimize a bestmicrowave-vacuum drying processing and the optimum conditions was as follows:microwave power density1.86W/g, vacuum degree0.078MPa. Under this drying condition,the drying time, polysaccharide preservation ratio, dissolve time and sensory evaluationwould be35.07min、96.04%、2.21min、9.74, respectively. Under the quality analysisexperiment, the polysaccharide content in Lycium barbarum L solid beverage was more than6.65%, and the sensory quality and flavor of product were good.