Different Technologies For Extracting Flavonoids From Pueraria Lobata And Its Application In Milk Beverages

China is rich in Pueraria lobata resources, presently the application of Pueraria lobate is focused on Pueraria. Flowers of Pueraria Lobata, even though containing a lot of flavonoid and with high value after properly drying, are less known and underutilized. But now they just used as a medicinal herb, and other aspects of application is less, create added value is not high, application is not extensive. Recently, with the increase of people ’s health care awareness, flavonoids are getting more and more attention and thus the development of Pueraria Lobata flowers is increasingly significant.In this study, Pueraria lobata was used as raw material to extract flavonoids, and we used the flavonoids to produce Pueraria flavonoids milk beverage introducing a new health drink to consumers providing a new health drink for consumers. The research focused on extraction of Pueraria lobata flavonoids by ultrasonic extraction method and high-intensity pulsed electric field method, and the key technologies of Pueraria lobata flavonoids milk beverage processing. The main results of the research were as follows:1. Using ultrasonic extraction method to extract Pueraria lobata flavonoids. Results were analyzed by response surface optimization on the basis of single-factor experiments, the extraction rates were taken as assessment indicators to study the effect of different conditions for Pueraria lobata flavonoids extraction rate. The results showed that, the yield rate of total flavonoids was 9.36% under the following conditions with the ethanol concentrations 60%, ratio of stuff-liquid ratio 1:41, ultrasonic power 320 W and ultrasonic time 17 min. And response surface optimization test was used to determine the influence of various factors on the yield of Pueraria lobata and the results were as follows: stuff-liquid > ethanol concentrations > ultrasonic power > extraction time.2. Using high-intensity pulsed electric fields to extract Pueraria lobata flavonoids, the effects of ethanol concentration, the ratio of material to liquid,electric field intensity and electric pulse number on extraction of Pueraria lobata flavonoids were studied by single factor experiment and response surface methodology. The results showed that, the yield rate 10.37% by total flavonoids was achieved with the ethanol concentrations 60%, the ratio of stuff-liquid ratio 1:32, electric field intensity 16kv/cm, electric pulse number 8, and the extraction rate was higher than the ultrasonic method. And response surface optimization test to determine the degree of influence of various factors on the yield of Pueraria lobata flavonoids stuff-liquid> electric field intensity> ethanol concentrations> electric pulse number.3. By sensory evaluation to determine the best formulation for Pueraria lobata flavonoids milk beverage, using the Pueraria lobata flavonoids which was extracted by high-intensity pulsed electric field, milk, fine white sugar and honey. The results showed that concentrated liquid of Pueraria lobata flavonoids 12%, 40% milk added, sugar added amount of 8%, and honey0.5%. The product is light brown and drinks homogeneous, taste smooth, and has particular aroma of Pueraria lobata.4. In order to ensure the stability of the beverage, the optimal formula of stability was determined by stability. The results showed that the amount of CMC 0.20%, the beverage had uniform structure, no delamination, no precipitation, and with a higher stability.