Compositions And Bioactivities Of Extractable And Non-extractable Polyphenols In Pyracantha Fortuneana Fruit And Passion Fruit Pomace

Due to the manner in which fruit and vegetables are consumpted and processed,a significant amount of them are traditionally discarded,which not only causes waste of resources but also causes environmental pollution.The pomace rich in polyphenols which have good prevention and adjuvant treatmentg on various cardiovascular diseases,diabetes,tumors,aging and other chronic diseases.Traditional polyphenol extraction methods focus on extractable polyphenols(EPP)while neglecting non-extractable polyphenols(NEPP).The purpose of this paper is to explore the comprehensive characterization of EPP and NEPP in pomace,the existent form of NEPP,and compare the antioxidant activity and hypoglycemic activity of EPP and NEPP,in order to provide a material basis for the resource utilization of polyphenols in pomace.In this paper,Pyracantha fortuneana fruit and Passion fruit peel were used as research objects.The comprehensive characterization of EPP and NEPP of polyphenols were studied by spectrophotometry and LC-MS,and further through pectinase,cellulose and the snail enzyme were used to extract NEPP from the pomace after EPP extraction and the existence form of NEPP was explored.The antioxidant activities of EPP and NEPP were evaluated by three methods: T-AOC total antioxidant activity,DPPH scavenging free radical ability and FRAP iron ion reducing ability.Alpha-glucosidase inhibition and alpha-amylase inhibition assays were applied to explore the hypoglycemic activity of EPP and NEPP.The main findings are as follows:1)The content of NEPP in the Pyracantha fortuneana fruit pomace and the passion fruit peel was 40.6 ± 0.7% and 53.2 ± 0.6%,respectively,indicating that the content of NEPP in the two pomace was equal to or more than EPP.In both pomace,the content of total flavonoids in NEPP is higher than that in EPP,while the content of proanthocyanidins in EPP is higher.It is preliminarily concluded that both pomace EPPs contain cyanidin-3-glucoside,cyanidin-3-galactoside and rutin while HPP contains more various monomer polyphenols than EPP by using LC-MS technology;Compared with Pyracantha fortuneana fruit pomace,the HPP of passion fruit peel contains higher content of Edulilic acid?myricetin,caffeic acid and protocatechuic acid,and polyphenols of EPP and HPP(Hydrolyzable polyphenols,belong to NEPP)from Passion fruit peel are more various.2)The enzymatic hydrolysis of pectinase,cellulase and snail enzyme in the pomace residue after extracting EPP respectively,the extractable rates of NEPP of Pyracantha fortuneana fruit pomace were: 26.0 ± 1.1%?27.3 ± 0.7% and 25.5 ± 0.3%,respectively.The extractable rates of 0.3%,passion fruit peel NEPP were: 26.1 ± 1.5%?28.0 ± 2.3% and 37.8 ± 2.1%,respectively.The addition of the cell wall enzymes pre-treatment can partially increase the polyphenol extraction rate,but the extraction amount of NEPP is lower than that of the acid treatment.It shows that there are interactions such as intermolecular,covalent ester bond and glycosidic bond between NEPP and cell wall components.3)The total antioxidant capacity of EPP,HPP and NEPA from Pyracantha fortuneana fruit pomace was 460.28 ± 7.51?2798.79 ± 170.20 and 325.64 ± 5.01 ?g trolox/mg GAE,respectively,the DPPH free radical scavenging IC50 of them was 81.95 ± 1.52?60.72 ± 11.62 and 28.12 ± 2.72 ?g GAE/m L,respectively,and the FRAP iron ion reducing ability was: 777.53 ± 36.58?449.34 ± 6.84 and 478.15 ± 8.14 ?g Ascorbic acid/mg GAE;The total antioxidant capacity of passion fruit peel EPP,HPP and NEPA were 219.43 ± 5.01?0.83 ± 0.08 and 1544.89 ± 47.56 ?g trolox/mg GAE,DPPH free radical scavenging IC50 were: 128.87 ± 7.63?78.56 ± 4.77 and 20.44 ± 0.54 ?g GAE/m L,respectively and the FRAP iron ion reduction abilities were: 501±64.58?394.92 ± 22.83 and 1195.28 ± 44.28 ?g ascorbic acid / mg GAE.Both Pyracantha fortuneana fruit pomace and Passion fruit perphenol have good antioxidant activity.NEPP has stronger DPPH free radical scavenging ability and is stronger than or equivalent to VC(IC=70.68 ± 0.65 ?g/m L).4)Both Pyracantha fortuneana pomace and Passion fruit peel polyphenols have good hypoglycemic activity in vitro.For the inhibition ability of ?-glucosidase,Pyracantha fortuneana fruit pomace EPP is stronger than NEPP,and Passion fruit peel NEPP is stronger than EPP and the HPP part of the passion fruit peel NEPP has the strongest inhibitory effect on ?-glucosidase,which corresponds to the above finding that in the passion fruit peel contains more phenolic acid;The inhibition ability of ?-amylase of EPP and NEPP from passion fruit peel is stronger than that of the corresponding extract part of Pyracantha fortuneana fruit pomace.The inhibition ability of ?-amylase of NEPP from both pomace is stronger than EPP and that of acarbose(IC50=30.48 ± 0.21 ?g/m L),indicating that NEPP contains a large amount of hypoglycemic-potential natural alpha-amylase inhibitory molecules.In this paper,the compositions and potential bioactivities of NEPP in pomace were revealed from the aspects of composition analysis,antioxidant activity and hypoglycemic activity in vitro,which provided a scientific basis for the further development and utilization of NEPP in plants.