Tudy On Extraction Of Flavonoids In Ginkgo Biloba Leaves By Enzymatic Method

Flavonoids widely exist in some plants and berries in nature,with a wide range of efficacy Solvent such as ethanol,water,methanol,etc,are often used as the extracting agent of Flavonoids..Water immersion extraction costs low,but the extraction rate is low either;organic solvent extractions such as ethanol has high cost.Enzymatic technology with the advantages of its high efficiency,non-toxic,mild reaction conditions has been widely used in the extraction of bioactive ingredients.This research mainly include extracting flavonoids from ginkgo biloba,optimizing the process of the traditional methods and determining the best technological conditions for extraction of flavonoids from ginkgo biloba leaves by the enzymatic technology.The main work is as follows:Flavonoids analysis has been improved.After respectively adding 0.7 mL 5% sodium nitrite solution,0.7 mL 10% aluminum nitrate aqueous solution,and 5 mL 4% sodium hydroxide aqueous solution,with 30% ethanol in volume,then flavonoids could be measured the absorbance value under the condition of 508 nm wavelength.Rutin used as a standard is formulated into a series of concentrations of the solution,calculating the standard curve regression equation is Y= 0.0763A+ 0.0032,r= 0.9995,the absorbance linear is in the range of 0.1~0.6.We have reaserched the circulating extraction of Ginkgo Flavone in Ginkgo biloba leaves by the ethanol-water-miscible solvent.The effect of ethanol concentration,extraction temperature,extraction time,solid-liquid ratio and extraction times on the extraction of flavonoids from Ginkgo biloba leaves was also considered.Optimal conditions were that ethanol concentration was 60%,extracted temperature was 70 C,extracted time was 3 h,solid-liquid ratio was 1:30,the number of extracted passes was three times.Under these conditions,the extraction rate can reach 75%.We have researched the extraction conditions of flavonoids in Ginkgo biloba leaves by enzymatic method.Through a variety of single-factor test,analyzing the impact under various conditions on the extraction rate of flavonoids,in order to determine the type and proportion of the enzymes,enzyme dosage,extracting time,extracting temperature,the feature of Ginkgo biloba's size,ratio of solid to liquid and extracting speed.According to the results of orthogonal test,the best technological conditions was that Ginkgo biloba feature size was 25,the use of 90 U/g cellulase pectinase =1:1complex enzyme,ratio of material to liquid was 1:20,pH was 5.5,at a temperature of 50 ?,and extracted for 3 h.In this method,we could get the highest extraction rateIn a word,the extraction process of flavonoids by enzymatic method is mild reaction conditions,simple process,non-toxic,suitable for industrial promotion cost and convenient.