The Extraction,Purification And Antioxidant Activity For Passion Fruit Polyphenols

Three parts were included in this study.First of all,the study was planned to optimize the passion fruit polyphenols’extraction parameters of three extraction methods,ultrasound assisted cellulase extraction,ultrasound-assisted ethanol extraction and ultrasound-assistedβ-cyclodextrin extraction,respectively,using Box-Behnken response surface design.Then,the purification of the crude extracts via four macroporous resins were exploration.Moreover,the antioxidant activities of polyphenols from passion fruit were evaluated.Part one:Study on the extraction technology of passion fruit polyphenolsThe study was aimed to develop an effective extraction technology of passion fruit polyphenols,via optimizing the parameters of three methods of ultrasound assisted extraction.First of all,the efficient parameters of extract factors on the polyphenols content were studied,using the single-factor experiments.Then,the extraction technology was optimized by Box-Behnken response surface design,basing on the results of the single-factor experiments.Finally,comparing with three extraction methods,the best extraction technology of passion fruit polyphenols used ultrasound-cellulase extract was confirmed with.The optimized conditions were as follow:ultrasound temperature 30℃,ratio of liquid to solid 49.97 mL/g,ultrasound time 50 min,pH=7.0,the extract content 22.70 mg Gae/g dw.Part two:Study on the purification and separation of polyphenols from passion fruitThe study was aimed to obtain high purity of passion fruit polyphenols via purifying by macroporous resin.First,the macroporous resins with different belongings were used for separation of polyphenols from passion fruit.Comparing the abilities of static adsorption and desorption,dynamic adsorption and desorption,we proved that AB-8 macroporous resin had a higher purity rate as the best resin to isolate passion fruit polyphenols,and used 350 mL of 95%ethanol that can achieve complete desorption.Part three:Study on the antioxidant activities of passion fruit polyphenols in vitroThe antioxidant activities of polyphenols form passion fruit were evaluated via free radical of DPPH and ABTS~+in vitro.The antioxidant activities of polyphenols were compared with vitamin C.The results showed that the passion fruit polyphenol behaved an excellent ability to scavenge DPPH radical and ABTS radical by ultrasonic-cellulase method.Compared with vitamin C,the maximum scavenge DPPH radical ability was 20.14 mg VCE/100g,and the scavenge ABTS~+radical ability was 539.14 mg VCE/100g.In addition,the antioxidant activity of passion fruit polyphenols was obviously related to its content.