| In order to study the biological activity of coconut inflorescence sap phenolic and polysaccharides extracts, using fresh and natural fermented 24h coconut inflorescence sap as object of study. Extraction method used to obtain phenolic; alcohol method used to extract polysaccharides. The major researches contain:The antioxidant study of fresh and fermented coconut inflorescence sap phenolic extraces; the antioxidant syudy of coconut inflorescence sap polysaccharides extracts; improves of metal iron on superoxide radical scavenging activities of coconut inflorescence sap; on this basis, though the RP-HPLC determination the phenolic's variety and content.The antioxidant potential of fresh and natural fermented coconut sap extracts were studied by using peroxidation of phospholipids liposomes assay, DPPH radical and hydroxyl radical scavenging activity, metal chelating activity, and ferric reducing power with BHT, gallic acid, Trolox as standards. The results indicate that the natural fermented coconut sap extract has a higher peroxidation of phospholipids liposomes inhibiting activity, DPPH radical and hydroxyl radical scavenging activity, metal chelating activity than fresh coconut sap, while the fresh coconut sap extract has a stronger ferric reducing power than natural fermented coconut sap extract. Additionally, the total phenolic content determined by Folin-Ciocalteau's reagent is 0.061mg/mL for fresh coconut inflorescence sap extract and 0.087mg/mL for natural fermented coconut sap.The antioxidant potential of coconut inflorescence sap polysaccharides extracts were studied by using super oxide radical scavenging activity, reducing power, DPPH radical scavenging activity, hydroxyl radical scavenging activity and so on. The results:the super oxide radical scavenging activity within the limit of 50-300ug/ml is with the increasing of the concentration increase; the reducing power of sample, Vc and BHT is with the increasing of the concentration increase, in the same concentration the sample is lower with the Vc and BHT; the DPPH radical scavenging activity of all is with the increasing of the concentration increase; the hydroxyl radical scavenging activity: gallic acid>polysaccharides extractes>Trolox>BHT.Superoxide anion radical scavenging activity and xanthine oxidase inhibition activity of fresh and naturally fermented coconut sap have been investigated in this work with protocateechuic acid as standard. The result shown that fresh and naturally fermented coconut sap has a high superoxide anion redical scavenging activity, but a low xanthine oxidase inhibition activity. The Zn2+ can improve their superoxide anion radical scavenging activity and xanthine oxidase inhibition activity, while the Cu2+ only has better effect on its superoxide anion radical scavenging activity.The phenolic compounds in fresh and natural fermented 24h coconut inflorescence sap were analyzed by high performance liquid chromatography(HPLC). Chromatographic separation was performed by Zorbax SB-C18 column(150 mm×4.6 mm,5.0μm) using the mobile phasw gradient elution of methanol-acetic acid(2%) mixture at 30℃. The flow rate was 1.0mL/min. Several phenolic compounds, including galic acid, protocatechuic acid, caffeic acid, p-coumaric acid and galangin, were found both in fresh and natural fermented 24h coconut inflorescence sap. The total phenolic contents in natural fermented 24h coconut inflorescence sap were found to be much higher than those in fresh ones.The dissertation first systematic study of the coconut inflorescence sap phenolic and polysaccharides extract, apart and biological activity, discover that the coconut inflorescence sap contain comparatively many phenolic and polysaccharides. The coconut inflorescence sap have determinate antioxidative activity, it complexes with the iron could exhibit the SOD mimic activity to inhibit the xanthine oxidase activity. Taking the coconut inflorescence sap as raw materials to processing the functional drinks could extend the industrial chain of nut production and increase product added value, its has great significance for the comprehensive utilization and deep processing of coconut inflorescence sap. |
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