Dissertation > Excellent graduate degree dissertation topics show

Ultrasound Effects on Molecular Chain, Structure and Antioxidant Activity of Marine Fucoidan

Author: GuoXin
Tutor: YeXingQian
School: Zhejiang University
Course: Of Food Science
Keywords: sulfated polysaccharides fucoidan ultrasound degradation antioxidant activity
CLC: TS254.4
Type: Master's thesis
Year: 2014
Downloads: 21
Quote: 0
Read: Download Dissertation

Abstract


Fucoidans are a class of sulfated polysaccharides from marine organisms with multi-activities. They has been reported to have various biological benefits, such as anticoagulant and antithrombotic activities, antiviral activityies, antioxidant activities, promotion of neural stem cell proliferation, protection against gastric ulcer and so on. Native fucoidan is usually with high molecular weight (Mw), which limited its utilization by human body. The Mw and structure of polysaccharides are reported to be related to their biological activities. Thus, more and more researches are focus on reducing the Mw of fucoidan to improve its diffusion into biological tissues. Generally, the low Mw polysaccharide is mainly prepared by chemical methods such as acid hydrolysis or free radical depolymerization, which would destroy its structure and damage the bioactivity. Researchers hope to find a more mild and effective way to degrade the polysaccharides.In this thesis, the ultrasonic method was applied to degrade the fucoidan from sea weeds and sea cucumber Isostichopus badionotus. The Mw, structure and antioxidant activities changes of the fucodian during ultrasonic, as well as the degradation kinetics was investigated to optimize and prediction the degradation of fucoidan. The results showed:(1) The ultrasonic process was a mild and effective way to reduce the Mw of the fucoidan. The degradation efficiency was directly proportional to ultrasonic intensity, and inversely related to temperature and sample concentration.(3) Degradation kinetics model of fucodian from Isostichopus badionotus quite was fitted to1/Mt-1/M0=kt during5-45℃.(4) According to the results of response surface methodology, the optimum temperature and ultrasonic intensity of ultrasonic degradation of fucoidan of seaweed and sea cucumber Isostichopus badionotus was7.83℃,469W/cm2and12℃,508W/cm2, respectively.(4) Structure analysis suggested that ultrasound treatment is an effective approach to decrease the Mw of fucoidan with only minor structural destruction. The fucoidan from Isostichopus badionotus have kept the tetrasaccharides-repeats as the original after ultrasonic process, with some destruction on non-sulfated fucose in the tetrasaccharide-repeat. Some sulfate groups in sea weed fucoidan might suffer minor destruction, especially those substituted at the C-4positions.(5) Antioxidant activity assay showed the antioxidant activity was slightly improved after a short period of ultrasound treatment. However, a long period of ultrasound treatment would paly a bad effect on the antioxidant activity of the degraded fucoidan.(6) Based on the results of the structure analysis and the antioxidant activity, we speculated the possible mechanism of the ultrasonic acted on the fucoidan may be a combination a mechanical and free radical degradation. The mechanical effect from shear force may paly a major role in degrading the fucoidan from Isostichopus badionotus.

Related Dissertations

  1. Study on the Degradation of Unsaturated Polyester Resin and Fiber Reinforced Polymer in Hot Compressed Water,TQ320.1
  2. Competitive Adsorption of Phenolic/Ethanol onto Silica Fiber Effected by Ultrasound in RTM Process,TB332
  3. Research on Methods of Medical Ultrasound Image Denoising,TP391.41
  4. Research on Feature Extraction and Classification of Doppler Ultrasonic Blood Flow Signals of Wrist Radial Artery,TP391.41
  5. Process Optimization and Degradation Kinetics for Microwave Vacuum Drying of Different Traditional Chinese Medicine Extract,TQ461
  6. Study on the Preparation of the Low Molecular Weight Fuciodan from Sargassum Henslowianum (C.Agardh) and Anti-tumor Activity,TS254.9
  7. Study on Activated Carbon Supported Cerium Catalytic Ozone Oxidation of Chloramphenicol,X703
  8. The Study of Preparation and Photocatalytic Activity of TiO2 by Electrospinning,O614.411
  9. Process and Mechanism of Eucalyptus Pulp Bleaching Catalysed by Cu2+/Co2+,TS745
  10. The Research on Sulfate Leaching Properties of Cation-exchange Resin Used in Power Plants,TQ425.23
  11. Study of Nitrobenzene Wastewater’s Treatment by Combination of Immobile Phanerochaete Chrysosporium and Activated Sludge,X703
  12. Study on the Breeding of High Efficient Detoxification Strains and Suggestion Parameters of Solid Fermentation on Cottonseed Meal,S816.6
  13. Detection of Exogenous Recombinan DNA of Transgenic Rice and Its Rice Product,S511
  14. Study on Detection of Transgenic Ingredients in Genetically Modified Cottonseed Meal and Its Degradation during Feed Processing,S816
  15. Isolation and Characterization of Carbendazim-Degrading Strains, Cloning and Expression of the mheI Gene,X172
  16. Isolation, Identification and Degradation Characteristics of a Benazolin-Ethyl Degrading Bacteria and Degradation Pathway,X172
  17. Isolation and Identification of Pyrene-Degrading Strain SE12 and Its Degrading Effect,X172
  18. The Interaction of Fluroxypyr with the Green Alga Chlamydonomas Reinhardtii,S482.4
  19. Isolation, Identification and Degrading Characteristic of a Cyhalofop-Butyl-Degrading Bacteria, and Cloning, Expression of a Cyhalofop-Butyl-Hydrolyzing Gene chbH,X172
  20. A Study on Environmental Behaviors of 2,4-D Butylate,TQ450.2
  21. Study on Extraction, Isolation and Antioxidant Activity of Lignans of Sesame Cake,TS229

CLC: > Industrial Technology > Light industry,handicrafts > Food Industry > Aquatic products processing industry > Aquatic food processing and preservation
© 2012 www.DissertationTopic.Net  Mobile