Studies On The Extraction Process And Application Of Polyphenols From Robinia Pseudoacacia L. Flowers

Robinia pseudoacacia L. was one of the fast-growing commercial trees. They are widely distributed in many countries including China. Their flowers are not only high-yield, but also be used as one kind of natural edible vegetable. It has been reported that they contain a great amount of nutrients and potentially health-promoting phenolic compounds. Therefore, they have high nutritional and functional values. Robinia pseudoacacia L. flowers were taken as main material in this research, and the optimum extraction condition was obtained by response surface methodology. The phenolic crude was purified by the macroporous resin, and the phenolic compounds in crude extract were determined by HPLC. The spray drying technology was used to microcapsule to the polyphenols. The results indicated:1,The phenolic content of Robinia pseudoacacia L. flowers determined by modified Folin-Ciocalteus method was 1.083g/100g.2,The optimum extraction conditions were as follows: the temperature was 35℃, the power of pulsed ultrasonic was 110W, the ultrasonic time was 36min, and solvent to solid ratio was 20:1(ml/g). Under these conditions the yield of polyphenols was up to 7.891% fresh weight.3,The high-performance liquid chromatography conditions were as follows: Shimadzu ODS column (4.6mm×150mm, 5μm); column temperature was 30℃; injection volume was 10μl; detection wavelength was 345nm, flow rate was 1.0ml/min; mobile phase A 100% methanol, B 5% acetic acid; gradient elution: 0-5min, 15%B-30%B; 5-30min, 30%B-80%B, 2min continued. Phenolic compositions in crude extract were elucidated as followings: caffeic acid, chlorogenic acid, gallic acid, acacetin, rutin, quercetin, kaempferol, and luteolin.4,The spray drying technological conditions are as follows: Arabic gum: Beta-the ring-like dextrin is 1: 7, the sodium alginate content is 0.3%, the emulsifier single glyceride content is 0.4%. The core material and the wall material ratio is 25mL/g, the content of solid is 15%, then enters wind temperature is 150℃, and the amount of air is 40%.