桑葉為�？浦参锷orus alba L的干燥葉,藥食同源。桑葉多糖具有降血壓、血脂、抗炎等包括免疫刺激作用等多種生物活性,本研究以桑葉為研究對象,研究了桑葉多糖（MLP80%）的提取工藝、理化性質(zhì)及抗輻射氧化脅迫作用。對超聲波輔助和熱水浸提2種提取工藝后桑葉殘渣的形態(tài)特征和結(jié)構(gòu)變化進行掃描電鏡（SEM）分析,表明超聲輔助提取對提高生物活性物質(zhì)的傳質(zhì)速率有積極作用。結(jié)合單因素試驗,采用響應(yīng)面分析法優(yōu)化桑葉多糖（MLP）的超聲輔助提取工藝,確定了最佳提取條件:提取溫度60℃,超聲功率60 W,提取時間30 min,提取溶劑（水）與原料的比例（V/W,mL/g）為30:1;多糖提取率為6.86±0.15%。采用乙醇對桑葉多糖進行分級,得到4個多糖級分（MLP20%、MLP40%、MLP60%和MLP80%）。通過體外抗氧化活性試驗篩選,MLP80%具有更好抗氧化活性。采用化學(xué)和物理分析方法,測定了MLP80%和MLP中多糖、蛋白質(zhì)、糖醛酸、硫酸根和總多酚的含量、溶解度和溶脹度等理化特性,MLP80%多糖含量顯著高于MLP（P≤0.05）,而MLP中蛋白質(zhì)、糖醛酸和總多酚含量顯著高于MLP8... 

【文章頁數(shù)】：97 頁

【學(xué)位級別】：碩士

【文章目錄】：
摘要
Abstract
Chapter1 Introduction
    1.1 Source,Background and Significance of the Research
        1.1.1 Source of the Research project
        1.1.2 Research background
        1.1.3 Theoretical and practical Significance of the Research
    1.2 Background of mulberry polysaccharides
    1.3 Biological properties of mulberry leaf
        1.3.1 Antihyperglycaemic effect
        1.3.2 Antihyperlipidaemic effect
        1.3.3 Anti-obesity effect
        1.3.4 Anti-oxidative effect
        1.3.5 Anti-inflammatory effect
    1.4 Relationship between Polysaccharide structure and bioactivity
    1.5 Polysaccharide extraction methods
    1.6 In ovo treatment
        1.6.1 Advantages of in ovo model
        1.6.2 In ovo administration and the immune System
        1.6.3 Immune status indicators
    1.7 Oxidative stress and immunity
    1.8 Research contents
Chapter2 Materials and methods
    2.1 Chemical reagents and laboratory equipment
        2.1.1 Chemical reagents
        2.1.2 Laboratory equipment
    2.2 Extraction method
    2.3 Preparation of crude polysaccharide
    2.4 Optimization of the extraction conditions
        2.4.1 Single factor experiments
        2.4.2 Experimental design of Response surface model
    2.5 Isolation of polysaccharide fractions and their antioxidant activity in vitro
        2.5.1 Assay of DPPH radical scavenging activity
        2.5.2 Assay of ABTS radical scavenging activity
        2.5.3 Assay of Hydroxyl radical scavenging activity
        2.5.4 Assay of Superoxide radical scavenging activity
        2.5.5 Assay of reducing power
    2.6 Physicochemical properties of crude MLP and MLP80%
        2.6.1 Determination of chemical contents
        2.6.2 Determination of solubility and swelling power
        2.6.3 Determination of molecular weight
        2.6.4 UV analysis
        2.6.5 FT-IR spectrometric analysis
    2.7 Effects of MLP80%in ovo
        2.7.1 In ovo Injection and Egg Management
        2.7.2 Experimental design
        2.7.3 Body weight determination
        2.7.4 Determination of organ indexes
        2.7.5 Lipid peroxidation and antioxidant capacity in serum
        2.7.6 Determination of immune cytokines
    2.8 Statistics analysis
Chapter3 Extraction,isolation and physicochemical properties of polysaccharide from mulbery leaves
    3.1 Introduction
    3.2 Extraction of mulberry leaf polysaccharides
        3.2.1 Scanning electron microscopy(SEM)
        3.2.2 Single factor experiments
            3.2.2.1 Effect of extraction temperature on MLP yield
            3.2.2.2 Effect of solid to liquid ratio on MLP yield
            3.2.2.3 Effect of extraction time on MLP yield
            3.2.2.4 Effect of ultrasonic power on MLP yield
        3.2.3 Optimization of MLP extraction by response surface model(RSM)
            3.2.3.1 Model fitting and statistical analysis
            3.2.3.2 Analysis of response surface plots
            3.2.3.3 Verification of predictive model
    3.3 Isolation of polysaccharide fractions and their antioxidant activity in vitro
        3.3.1 DPPH radical scavenging activity
        3.3.2 ABTS radical scavenging activity
        3.3.3 Hydroxyl radical scavenging activity
        3.3.4 Superoxide radical scavenging activity
        3.3.5 Reducing power
    3.4 Physicochemical properties of crude MLP and MLP80%
        3.4.1 Determination of chemical contents
        3.4.2 Solubility and swelling power
        3.4.3 Determination of molecular weight
        3.4.4 UV analysis
        3.4.5 FT-IR spectrometric analysis
    3.5 Brief Summary
Chapter4 Effects of MLP80%against radiation induced oxidative stress
    4.1 Introduction
    4.2 In ovo pretest experiments
        4.2.1 MLP concentration
        4.2.2 Radiation dose
    4.3 Effects of MLP80%in ovo model
        4.3.1 Effect of MLP 80% on body weight
        4.3.2 Effect of MLP 80% on organ indexes
        4.3.3 Effect of MLP 80% on lipid peroxidation
        4.3.4 Effect of MLP 80% on antioxidant capacity
            4.3.4.1 Effect of MLP 80% on catalase(CAT)
            4.3.4.2 Effect of MLP 80% on glutathione peroxidase(GSH-Px)
            4.3.4.3 Effect of MLP 80% on superoxide(SOD)
        4.3.5 Effect of MLP 80% on cytokines in serum
            4.3.5.1 Effect of MLP 80% on interleukin-2(IL-2)
            4.3.5.2 Effect of MLP 80% on interleukin-12(IL-12)
            4.3.5.3 Effect of MLP 80% on interferon-γ (IFN-γ)
    4.4 Brief Summary
Conclusion
結(jié)論
References
Appendix
Papers and Other Achievements Published during Master's Degree Study
Acknowledgement
Resume



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