A study on the effect on an ultrasound-enhanced aqueous two--phase extraction and purification of plant polysaccharides

目录

声明

致谢

1.1General background

1.2Astragalus membranaceus

1.2.1 Composition

1.2.2 Health-related properties

1.3Lentinus edodes

1.3.1. Composition

1.3.2. Health-related properties

1.4. Extraction of polysaccharides

1.5.Conventional polysaccharide extraction methods

1.5.1. Hot water extraction

1.5.2. Reflux extraction

1.5.3. Complex enzyme hydrolysis method

1.6.Novel polysaccharide extraction methods

1.6.1. Ultrasound-assisted extraction

1.6.2. Subcriticalwater extraction (SWE)

1.6.3.Microwave-assisted extraction (MAE)

1.6.4. Enzyme assisted extraction (EAE)

1.6.5. Aqueous two-phase system

1.7. Traditional deproteinization methods of polysaccharides

1.7.1. Sevag Method

1.7.2. Trichloroacetic acid method (TCA)

1.7.3. NaCl method

1.7.4. Calcium chloride method

1.8. Traditional purification methods.

1.8.1. Column Chromatography

1.8.2.High-Pressure Liquid Chromatography (HPLC)

1.8.3. Gas Chromatography

1.8.4 Ethanol graded precipitation

1.9.Significance and Justification of the study

1.10. Specific objectives

2.1. Introduction

2.2.MATERIALS AND METHODS

2.2.1.Materials and chemicals

2.2.2. Plant material preparation

2.2.3. Pre-treatment of Astragalus root powder

2.2.4.Phase diagram

2.2.5.Selection of ethanol/salt ATPS

2.2.6 Dual-frequency ultrasound-assisted aqueous two-phaseextraction (DFu-AATPE)

2.2.7. Conventional extraction experiments

2.2.8.Response surface methodology

2.2.9. Desalination

2.2.10. Thermodynamics

2.2.11. Chemical analysis

2.2.12.Structural Analysis

2.2.13. Spectral analysis

2.2.14. Radical scavenging activity assays

2.2.15. Statistical analysis

2.3 RESULTS AND DISCUSSION

2.3.1. Phase diagram

2.3.2.Selection of ATPS

2.3.3. Single-factor experiments on DFu-AATPE

2.3.4. Optimization

2.3.5. Primary Characterization of APS polysaccharides

2.3.6. Thermodynamics

2.3.7. Desalination

2.3.8. Structural composition

2.3.9. Spectral analysis

2.3.10. Anti-radical activities

2.3.11.Mechanism of DFu-AATPE ofAstragaluspolysaccharides

2.3.12 Comparisonwith other extraction techniques

2.4. Conclusion

CHAPTER 3 SYNERGIZED SUBCRITICAL-ULTRASOUND-ASSISTED AQUEOUS TWO-PHASE EXTRACTION, PURIFICATION, AND CHARACTERIZATION OFLENTINUS EDODES POLYSACCHARIDES

3.1 Introduction

3.2.1. Chemicals and reagents

3.2.2. Plant material and pretreatment

3.2.3. Subcritical water extraction

3.2.4. Purification

3.2.5Comparison of Extraction methods

3.2.6. Response Surface Methodology

3.2.7. Ultrasound-assisted desalination

3.2.9. Structural characterization

3.2.10. Spectral analysis

3.2.11. Radical scavenging activity assays

3.2.12. Statistical analysis

3.3.1 Yield ofLentinusedodespolysaccharides

3.3.2. Optimization

3.3.3. Mechanism of Multi-frequency ultrasound-assisted aqueous two-phase extraction (MFU-AATPE) ofLentinusedodespolysaccharides

3.3.4 Chemical composition

3.3.5 Desalination

3.3.6. Structural Analysis

3.3.7. Spectral analysis

3.3.8 Radical Scavenging Activity Assays

3.3.9.Comparison with other extraction techniques

3.5. Conclusion

CHAPTER 4 CONCLUSION AND FUTURE WORK

4.1 General Conclusion

4.2. Novelty

4.3. Recommendations

参考文献

APPENDIX