Study On The Technological Conditions Of Extraction And Purification Of Flavonoids And Polysaccharides From Asparagus Officinalis Stems And Leaves

The extraction of active components from vegetable materials is one important direction of further vegetable processing development. This could not only increase the value of vegetable, but also made the vegetable waste to usefully. Asparagus is one of the important export vegetables in our country, and has numerous useless materials during processing, which courses environmental pollution and resource waste. The extraction and purification of flavonoids and polysaccharides from Asparagus officinalis stems and leaves, and their identification and medical effect were studied in this paper. The results were as following:1. The appropriate type of solvent, size of extracted material and extracting conditions, and their effects on total flavonoids in the stems and leaves of Asparagus officinalis were investigated. The comparisons were made between traditional heat extraction technique with or without ultrasonic application and microwave-assisted extraction by using orthogonal experiments were made, and mathematical models were built for each method by regression analysis. The results showed that: the best condition of heat extraction was temperature 80℃,ethanol concentration 55%,ratio of extracting material to ethanol of 1:15,for lh,and the mathematical model for predicting the amount of total flavonoids from stems and leaves of Asparagus officinalis was: y=10. 0565 -0.9114X₁+0. 0094X₁²+58. 0883X₂-42. 5978X₂²+1.1965X₃-0. 7377X₃²+6. 0177X4-1. 0244X₄²;the best condition of microwave-assisted extraction: ethanol concentration 80%, pH10, ratio of material to ethanol of1:25 for 5min, and the predicting mathematical model: y=-9.1803+1.6378X₁-0.1509X₁²+4.5216X²-1.1894X₂²+6.9266X₃+1.3543X₄.2. The ethanol extracted flavonoids from asparagus stems and leaves were initially purified by using macroporous resin. The optimal extracting parameters of sample concentration, adsorption speed, flowing rate and eluant gradient were investigated. The Result demonstrated that: NKA- II was better to separate the flavonoids than others. The adsorpting and eluant ratio can reach 87.56% and 98.79% respectively,and concentration of flavonoids can reach 11.3% after separation from 2.25% at the beginning.3. The extraction and initial purification techniques of Asparagus polysaccharides were investigated. The results showed that: The polysaccharides was largely affected by ethanol concentration, time of ethanol precipitation and the method of protein removing. The best condition of extracting polysaccharides from asparagus stems and leaves: 90℃, ratio of material to ethanol of 1:20, 3h of each time(twice). The comparisons among heat extraction technique, microwave-assisted extraction and ultrasonic extraction indicated that microwave-assisted extraction was better than other methods, which the extraction rate...