Study On Extraction,Purification And Antioxidant Activity Of Total Flavonoids From Pueraria By Deep Eutectic Solvents Method

In this paper,Pueraria lobata was used as raw material to extract flavonoids.The effects of different kinds of deep eutectic solvents and different extraction conditions on the extraction rate of Pueraria flavonoids were studied.AB-8 macroporous resin was used to purify the extract.Ultra performance liquid chromatography(UPLC)and mass spectrometry(MS)were used to qualitatively analyze the purified flavonoids.A kind of Pueraria flavonoids milk beverage was prepared.The main results are as follows(1)The effect of different deep eutectic solvents on the extraction rate of Flavonoids from Pueraria lobata was studied by single factor experiment.The results showed that the best extraction effect was obtained by using choline chloride/ethylene glycol deep eutectic solvent with water content of 40%and molar ratio of 1:5.In addition,with heating temperature,heating time,ultrasonic time and ultrasonic temperature as independent variables,the extraction rate of Pueraria flavonoids was taken as the target value.The results showed that the extraction efficiency was the best when the heating temperature was 82.13℃,the heating time was 40.28 min,the ultrasonic time was 30.54 min,and the ultrasonic temperature was 30.39℃.At this time,the yield of Flavonoids from Pueraria lobata was 15.6548mg/g.(2)AB-8 macroporous resin was used to purify the flavonoid extract from Pueraria lobata.The results showed that the best purification effect was obtained when the loading volume was 1BV,the loading rate was 1BV/h,the elution volume was 1BV and the elution rate was 2BV/h.The results showed that there were 10 kinds of flavonoids in the extract,and puerarin content was the highest(93.26%).The antioxidant activity and stability of Pueraria flavonoid extract were studied.The results showed that the DPPH·inhibition rate and ABTS~+inhibition rate were 86.55%and 98.52%,respectively.The stability of Pueraria flavonoids was better under the conditions of weak acid to neutral under 70℃.Glucose,sucrose,sodium ion and potassium ion had no effect on the stability of pueraria flavone.Zinc ion had a weak effect on Pueraria flavonoids,calcium ion and sodium sulfite had a weak effect It has a certain effect on the flavonoids of Pueraria lobata.(3)The optimum formula of Pueraria flavonoids milk beverage was determined by response surface methodology design.The results showed that the optimum formula of Pueraria flavonoids milk beverage was 8.41%,1.2%,30.30%,respectively When the content was 9.13%,the sensory quality of Pueraria flavonoids milk beverage was the best.The effects of three stabilizers on the stability of pueraria flavone milk beverage were studied.The results showed that the stability of three stabilizers on the prepared pueraria flavone milk beverage was better,but guar gum had a greater impact on the taste and other quality of the product due to its high viscosity.Under the same conditions,the stability of xanthan gum was higher than that of pectin,and the taste difference was not obvious.The addition amount is0.16%.