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Lactobacillus Plantarum Lp6发酵大豆蛋白粉及其抗氧化肽的研究

作　者: Amadou Issoufou
导　师: 乐国伟
学　校: 江南大学
专　业: 食品科学
关键词: Lactobacillus plantarum LP6 发酵大豆蛋白粉体外胰蛋白酶消化水解度营养属性抗氧化活性疏水性分子量分布肽段
分类号: TS201.2
类　型: 硕士论文
年　份: 2010年
下　载: 103次
引　用: 0次
阅　读: 论文下载

内容摘要

食物中的抗氧化物质如酚类化合物可以作为保健成分(抗癌及抗心血管疾病)、抗菌剂、风味物质、着色剂前体、胶体稳定剂以及螯合剂而发挥多种功效。发酵食品如大豆类产品已经存在数千年并被认为是许多有效抗氧化剂的来源。本文中,大豆蛋白粉分别在添加蛋白酶及不添加蛋白酶的情况下以Lactobacillus plant arum Lp6进行固态发酵。通过研究大豆蛋白粉(SPM)的Lactobacillus plantarum Lp6固态发酵评估可溶淀粉、酸性蛋白酶及时间对水解度(DH)和活细胞计数(VCC)的影响。为获得最大DH和VCC的发酵蛋白粉(FSPM),采用响应面法进行优化,得到最优试验条件为：可溶淀粉(0.4 g/g SPM)、酸性蛋白酶(0.1 g/g SPM)及时间(66h),最优条件下的结果为DH 22.58%和VCC 9.08(log CFU/g)。最优条件提高了发酵产物中低分子量肽(<20 kDa)的比例、蛋白含量(60.15%)。Lactobacillus plantarum Lp6和酸性蛋白酶的水解作用使产物中的游离氨基酸含量显著升高(从0.32提高到8.03g/100 g蛋白,P<0.01),也使蛋白溶解度显著提高(从29.33%提高到38.35%,P<0.01),另外,FSPM具有更高的体外胰岛素消化性。通过Sephadex G-15凝胶层析对发酵大豆蛋白水解物(FSPMH)进行分级,对各组分进行抗氧化活性、氨基酸组成和分子量分布的测定。结果显示：在凝胶层析得到的7各组分中,F2组分具有最高的DPPH自由基清除能力(59.43%)、OH自由基清除能力(72.80%)以及Cu2+螯合能力(44.47%) (P<0.01)；与其他几个组分相比,F2组分的氨基酸组成中抗氧化氨基酸含量最高(组氨酸3.46,丝氨酸5.78,缬氨酸4.08,赖氨酸11.49g/100 g蛋白),其分子量分布为170-1500 Da。利用反相高效液相色谱(RP-HPLC)对F2组分进行纯化,收集各洗脱峰并测定其DPPH自由基清除能力及Cu2+螯合能力,并通过LC-MS鉴定其氨基酸序列。结果表明：RP-HPLC分离组分P1具有出较强的DPPH自由基清除能力及Cu2+螯合能力,氨基酸序列显示其含有组氨酸。

全文目录

ACKNOWLEDGEMENT  6-7
LIST OF FIGURES  7-8
LIST OF TABLES  8-9
LIST OF ABBREVIATIONS  9-10
ABSTRACT  10-12
摘要  12-14
TABLE OF CONTENTS  14-17
CHAPTER Ⅰ INTRODUCTION AND REVIEW OF RELEVANT LITERATURE  17-29
  1.1 General Introduction  18-20
  1.2.Fermented Soybean Products:Some Methods,Antioxidants CompoundExtraction and their Scavenging Activity  20-25
    1.2.1.Introduction  20-21
    1.2.2.Methodologies of fermentation of soybean products  21-23
    1.2.3.Procedures of fermented soybean antioxidant extraction  23-25
  1.3.Antioxidant/Antiradical Activity of Fermented Soybean Extract  25-28
  1.4.Conclusion  28-29
CHAPTER Ⅱ OPTIMIZED LACTOBACILLUS PLANTARUM LP6 SOLID-STATEFERMENTATION AND PROTEOLYTIC HYDROLYSIS IMPROVE SOMENUTRITIONAL ATTRIBUTES OF SOYBEAN PROTEIN MEAL  29-49
  2.1.Introduction  31-32
  2.2.Materials and Methods  32-37
    2.2.1.Materials  32
    2.2.2.Fermentation  32-33
    2.2.3.Viable cell counts  33
    2.2.4.Preparation of hydrolysate  33
    2.2.5.Degree of hydrolysis  33-34
    2.2.6.Sodium dodecyl sulfate-polyacrylamide gel electrophoresis  34
    2.2.7.Scanning electron microscopy  34-35
    2.2.8.Chemical analysis  35
    2.2.9.Amino acid analysis  35-36
    2.2.10.In vitro trypsin digestibility  36
    2.2.11.Experimental design for optimization  36
    2.2.12.Statistical analysis  36-37
  2.3.Results and Discussion  37-48
    2.3.1.Fermentation conditions  37-39
    2.3.2.Surface response data  39-42
    2.3.3.Effect of fermentation and proteolysis on composition  42-46
    2.3.4.Scanning electron microscopy  46-47
    2.3.5.In vitro trypsin digestibility  47-48
  2.4.Conclusion  48-49
CHAPTER Ⅲ REDUCING, RADICAL SCAVENGING, AND CHELATION PROPERTIESOF FERMENTED SOY PROTEIN MEAL HYDROLYSATE BYLACTOBACILLUS PLANTARUM LP6  49-62
  3.1.Introduction  50-51
  3.2.Materials and Methods  51-55
    3.2.1.Materials  51
    3.2.2.Fermentation  51
    3.2.3.Preparation of fermented soy protein meal hydrolysate and determination ofits degree of hydrolysis  51-52
    3.2.4.Gel filtration on Sephadex G-15 of FSPMH  52
    3.2.5.Reducing power  52-53
    3.2.6.DPPH radical-scavenging activity  53
    3.2.7.Hydroxyl radical-scavenging activity  53-54
    3.2.8.Metal chelating activity  54
    3.2.9.Amino acid composition  54
    3.2.10.Determination of molecular weight distribution  54-55
    3.2.11.Statistical analysis  55
  3.3.Results and Discussion  55-61
    3.3.1.FSPMH fractionation  55-56
    3.3.2.Reducing power  56
    3.3.3.DPPH radical-scavenging activity  56-57
    3.3.4.Hydroxyl radical-scavenging activity  57-58
    3.3.5.Metal chelating activity  58
    3.3.6.Amino acid composition  58-60
    3.3.7.Molecular weight distribution  60-61
  3.4.Conclusion  61-62
CHAPTER Ⅳ IDENTIFICATION OF ANTIOXIDATIVE PEPTIDES, LACTOBACILLUSPLANTARUM LP6 FERMENTED SOYBEAN PROTEIN MEAL  62-89
  4.1.Introduction  64
  4.2.Materials and Methods  64-67
    4.2.1.Materials  65
    4.2.3.Fermentation Method  65
    4.2.4.Preparation of fermented soy protein meal hydrolysate extract  65
    4.2.5.Isolation of antioxidant peptides  65-66
    4.2.6.DPPH radical scavenging activity  66
    4.2.7.Metal chelating activity  66-67
    4.2.8.Peptide sequence analysis  67
    4.2.9.Statistical analysis  67
  4.3.Results and Discussions  67-72
    4.3.1.Antioxidant activity  67-69
    4.3.2.Isolation of antioxidant peptides and determination of amino acid sequences  69-72
  4.4.Conclusion  72-73
  5.General Conclusions and Recommendations  73-75
    5.1.General conclusions  73-74
    5.2.Recommendations  74-75
  6.References  75-89
LIST OF PUBLICATIONS  89

Lactobacillus Plantarum Lp6发酵大豆蛋白粉及其抗氧化肽的研究

内容摘要

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