Ultrasound-assisted ethanol extraction and purification of flavonoids from walnut peel
Walnut is a traditional economic tree species in China.With the continuous increase of walnut production,the accumulation of walnut peel has gradually increased.Most of the walnut peel is discarded as agricultural waste,which not only causes a great waste of resources,but also causes pollution to the environment.Therefore,it has received much attention for turning walnut peel into treasure.The effects of different extraction solvents and different extraction methods on the extraction rate of flavonoids were compared to explore the optimal extraction and purification process of flavonoids from walnut peel.The extraction conditions were optimized using Box-Behnken experimental design,and the effects of loading mass concentration,loading flow rate,ethanol volume fraction and elution flow rate on the purification efficiency were explored.The results showed that the optimal flavonoids extraction method was ultrasonic-assisted ethanol extraction.The results of single factor experiment showed that the extraction rate of flavonoids from walnut peel was the highest when ethanol volume fraction was 50％,ultrasonic time was 45 min and ultrasonic temperature was 80 ℃.The optimal extraction conditions were ethanol volume fraction of 50.52％,ultrasonic temperature of 80.19 ℃ and ultrasonic time of 47.01 min.In this condition,the extraction rate of flavonoids was 52.45％.For the convenience of practical operation,the optimal extraction process was verified by ethanol volume fraction of 51％,ultrasonic temperature of 80 ℃ and ultrasonic time of 47 min,and the extraction rate of flavonoids from walnut peel was 52.53％,which was basically consistent with the software design results.Among the results of D3520,D101,HPD-600,AB-8 and DM130 macroporous resins on the adsorption and desorption rates of flavonoids from walnut peel,AB-8 macroporous resin exhibited the best purification efficiency on flavonoids.The results of dynamic adsorption experiment show that the best purification conditions of flavonoids were loading mass concentration of 4 mg/mL,loading flow rate of 3 BV/h,ethanol volume fraction of 70％,and elution flow rate of 2 BV/h.The purity of flavonoids after purification was 81.10％.This study was aimed at providing scientific basis and technical support for the extraction and purification of total flavonoids from walnut peel,solving the problem of resource waste and environmental pollution caused by the increase of walnut production year by year,and providing new ideas for the reuse of walnut peel in agriculture,food,medicine and other fields.
国家科技期刊平台
NSTL
万方数据
