Preparation Of Cyperus Esculentus Polysaccharide And Its Application In Protein Beverage

Cyperus esculentus,also known as sugar root fruit,has the efficacy of mild intestines and stomach and treatment of degenerative diseases.Polysaccharides,as the important active components of Cyperus esculentus,have antioxidant and other physiological functions.At present,there are few studies on the component analysis and application of Polysaccharides from Cyperus esculentus.In order to deeply explore the composition of Polysaccharides from Cyperus esculentus and improve its utilization value,we extracted the active polysaccharides from Cyperus esculentus and explored the components of polysaccharides and their application in protein drinks.The specific content is as follows:1.Polysaccharides WOCL-Z from Cyperus esculentus were extracted by cellulase method and their antioxidant properties were determined.The single factor and response surface methodology were used to optimize the extraction conditions.The optimal extraction conditions were determined as follows: enzymolysis time 34 min,enzymolysis temperature 61℃,enzyme dosage 1.7% and pH4.55.Under these conditions,the polysaccharide yield is 15.86%.The DPPH free radical scavenging rate and the hydroxyl free radical scavenging rate of Cyperus esculentus polysaccharide are60.54% and 72.82%,respectively.2.The neutral sugar fraction WOCL-N and acidic sugar fraction WOCL-A were obtained from the classification of WOCL-Z by DEAE-cellulose ion exchange method.The yields of the two sugars were 15.18% and 18.97%,respectively.The physicochemical properties of WOCL-Z,WOCL-N and WOCL-A were studied respectively.The results showed that there were differences in chemical composition and monosaccharide composition among the three sugars.WOCL-Z and WOCL-A had block structure and sheet structure,respectively.WOCL-N had a compact flocculent structure,and all three sugars contained characteristic absorption peaks of polysaccharides.The molecular weight of WOCL-N was 10.640 KDa and that of WOCL-A was 3.458 KDa.3.The effect of polysaccharides from Cyperus esculentus on the stability of yoghurt was studied by experiments.The optimal preparation conditions were obtained through single factor test and response surface methodology optimization.The optimal preparation conditions were as follows: lactic acid bacteria powder 0.41%,sugar 4.45%,Cyperus esculentus polysaccharide extract 16% and fermentation time 7 h.The yogurt with water holding capacity of 56.63% and sensory score of 90.33 was obtained through the validated test.The sensory indicators,stability indicators,nutritional composition and texture characteristics were taken as the factors to conduct the comparative test of the yousha bean polysaccharide yogurt,the polysaccharide-free yogurt and the commercially available yogurt with three different protein contents under the optimal conditions.The results showed that,on the comprehensive quality,the polysaccharide yogurt was close to the yogurt with high content of protein,and better than the polysaccharide-free yogurt and the commercially available yogurt with low content of protein.4.The effect of polysaccharides from Cyperus esculentus on the stability of peanut protein beverage was studied by experiments.Three kinds of hydrocolloids were selected by single factor test and orthogonal test,and the optimal proportion of composite hydrocolloid was obtained.The single factor and response surface methodology were used to optimize the extraction conditions using the centrifugal precipitation rate and stability coefficient as the index.The optimal extraction conditions were obtained as follows: the amount of oil-tea bean polysaccharide extract2.78%,the amount of monoglyceride 0.1%,and the ratio of peanut paste to liquid 1:15.5g/mL.The peanut protein beverage with the centrifugal precipitation rate 9.71% and stability coefficient 69.28% was obtained through the experimental results.The stability and texture properties of the three kinds of beverage were compared.The results showed that the stability of the beverage was better than that of the commercial protein beverage.The nutritional index of the beverage was close to that of the commercial protein beverage and better than that of the polysaccharide-free protein beverage.