Wheat Antioxidants

Liangli Yu, PhD, is an Associate Professor in the Department of Nutrition and Food Science at the University of Maryland in College Park, where she specializes in the chemistry andbiochemistry of nutraceuticals and foods. Dr. Yu received her PhD in food science from Purdue University in 1999.

"The book presents current information on antioxidant compounds of wheat." (Food Science and Technology Abstracts, September 2008)

• Contributors xiCHAPTER 1 OVERVIEW AND PROSPECTIVE 11.1 Introduction 11.2 Antioxidant Properties of Wheat Grain 21.3 Other Biological Activities of Wheat Antioxidants 31.4 Wheat Antioxidants: Opportunities and Challenges 5CHAPTER 2 ANTIOXIDANT PROPERTIES OF WHEAT GRAIN AND ITS FRACTIONS 72.1 Sample Preparation 82.2 Total Phenolic Content (TPC) and Total Antioxidant Capacity (TAC) of Wheat Fractions 82.3 Iron(II)-Chelating Activity of Wheat Fractions 112.4 Oxygen Radical Absorbance Capacity (ORAC) of Wheat Fractions 132.5 Inhibition of Photochemiluminescence (PCL) by Wheat Fractions 142.6 Effect of Milling and Pearling of Wheat on Inhibition of Low-Density Lipoprotein (LDL) Oxidation 172.7 Influence of Milling and Pearling on Homediated Supercoiled DNA Scission by Wheat 192.8 Conclusions 20CHAPTER 3 EFFECTS OF GENOTYPE, ENVIRONMENT AND GENOTYPE • ENVIRONMENT INTERACTION ON THE ANTIOXIDANT PROPERTIES OF WHEAT 243.1 Introduction 243.2 Genotype Effects 263.2.1 Total Phenolic Content 273.2.2 Phenolic Acid Composition 283.2.3 DPPH Scavenging Capacity 313.2.4 Superoxide Scavenging Capacities 313.2.5 Peroxyl Radical Scavenging Capacities 323.3 Environment Effects 323.4 Genotype by Environment Interaction Effects 333.5 Relative Contribution of G, E, and G • E Effects to Total Variation 353.6 Concluding Remarks 37CHAPTER 4 CAROTENOID, TOCOPHEROL, LIGNAN, FLAVONOID, AND PHYTOSTEROL COMPOSITIONS OF WHEAT GRAIN AND ITS FRACTIONS 424.1 Introduction 424.2 Phytochemical Composition of Wheat 434.2.1 Polyphenols (Lignans, Flavonoids) 434.2.2 Carotenoids 464.2.3 Tocopherols and Tocotrienols 484.2.4 Phytosterols and Phytostanols 494.2.5 Antioxidant Activities and Health Benefits 494.3 Conclusion 52CHAPTER 5 ANTIOXIDANT PROPERTIES OF WHEAT PHENOLIC ACIDS 545.1 Introduction 545.2 Phenolic Acid Contents in Wheat Grain and Fractions 545.3 Free Radical Scavenging Capacity of Wheat Phenolic Acids 595.4 Inhibitory Effect of Wheat Phenolic Acids on Lipid Peroxidation 645.5 Chelating Properties of Wheat Phenolic Acids 665.6 Other Antioxidant Activities of Wheat Phenolic Acids 665.7 Structure–Activity Relationship of Wheat Phenolic Acids 70CHAPTER 6 EFFECTS OF POSTHARVEST TREATMENTS, FOOD FORMULATION, AND PROCESSING CONDITIONS ON WHEAT ANTIOXIDANT PROPERTIES 736.1 Introduction 736.2 Wheat Postharvest Treatments 746.2.1 Wheat Flour Milling 746.2.2 Pearling or Debranning 766.2.3 Storage of Wheat and Wheat Products 776.2.4 Other Postharvest Treatments 786.3 Food Formulations 796.4 Food Heat Processing 826.5 Summary 86CHAPTER 7 ANTIOXIDANT PROPERTIES OF WHEAT-BASED BREAKFAST FOODS 887.1 Introduction 887.2 Whole Grains for Health & Wellness 887.3 Grains Classification and Consumption 897.4 Wheat Types, Morphology, and Composition 907.5 Role of Antioxidants in Wheat and Other Cereal Grains 907.6 Wheat Milling and Distribution of Antioxidants 917.7 Wheat-Based Breakfast Foods 927.8 Breakfast Meal Consumption and Demographics 927.9 Antioxidants in RTE Breakfast Cereals 937.10 Antioxidants and Bread Making 957.11 Conclusion 96CHAPTER 8 EFFECTS OF EXTRACTION METHOD AND CONDITIONS ON WHEAT ANTIOXIDANT ACTIVITY ESTIMATION 1008.1 Introduction 1008.2 Extraction Methods and Conditions 1018.2.1 Effects of Extraction Method 1058.2.2 Effects of Extraction Conditions 1068.3 General Considerations for Sample Preparation and Extraction 1138.4 Extraction Condition Recommendations for Wheat Antioxidant Property Estimation 114CHAPTER 9 METHODS FOR ANTIOXIDANT CAPACITY ESTIMATION OF WHEAT AND WHEAT-BASED FOOD PRODUCTS 1189.1 Introduction 1189.2 DPPH Radical Scavenging Capacity Assay 1209.2.1 Principles and Background 1209.2.2 Materials and Solutions Preparation 1219.2.3 Discussion 1249.3 ABTS Cation Radical (ABTS_+) Scavenging Capacity Assay 1259.3.1 Principles and Background 1259.3.2 Materials and Solutions Preparation 1269.3.3 Measuring Procedure 1279.3.4 Calculations 1279.3.5 Discussion 1289.4 Superoxide Anion Radical (O2__) Scavenging Capacity Assay 1309.4.1 Principles and Background 1309.4.2 Materials and Solutions Preparation 1319.4.3 Procedure 1319.4.4 Calculations 1319.4.5 Discussion 1329.5 Oxygen Radical Absorbing Capacity (ORAC) Assay 1339.5.1 Principles and Background 1339.5.2 Materials and Solutions Preparation 1349.5.3 Calculations 1359.5.4 Discussion 1369.6 Hydroxyl Radical (_OH) Scavenging Capacity (HOSC) Assay for Hydrophilic Antioxidants 1389.6.1 Principles and Background 1389.6.2 Materials and Solutions Preparation 1399.6.3 Calculations 1409.6.4 Discussion 1419.6.5 Other Reported Methods for Hydroxyl Radical Scavenging Capacity Estimation 1429.7 Hydroxyl Radical Scavenging Capacity Assay for Lipophilic Antioxidants Using ESR 1439.7.1 Principles and Background 1439.7.2 Materials and Solutions Preparation 1449.7.3 Procedure 1449.7.4 ESR Parameters 1449.7.5 Calculations 1459.7.6 Discussion 1469.8 Total Phenolic Contents Assay Using the Folin–Ciocalteu Reagent 1479.8.1 Principles and Background 1479.8.2 Procedure 1489.8.3 Calculations 1499.8.4 Discussion 1499.9 Iron(II) Chelating Capacity Assay 1509.9.1 Principles and Background 1509.9.2 Procedure 1539.9.3 Calculations 1549.9.4 Discussion 1549.10 Copper(II) Chelating Capacity Assay 1559.10.1 Principles and Background 1559.10.2 Materials and Solutions Preparation 1569.10.3 Procedure 1569.10.4 ESR Parameters 1569.10.5 Discussion 1589.11 Lipid Peroxidation Inhibition Assay (OSI) 1589.11.1 Principles and Background 1589.11.2 Results 1609.11.3 Discussion 1609.12 Low-Density Lipoprotein (LDL) Peroxidation Inhibition Assay 1629.12.1 Principles and Background 1629.12.2 Discussion 1659.13 Conclusions 166CHAPTER 10 APPLICATION OF ESR IN WHEAT ANTIOXIDANT DETERMINATION 17310.1 Introduction 17310.2 The Principles of ESR 17410.3 The Application of ESR in Food Systems 17610.4 ESR Determination of Wheat Antioxidants 17910.4.1 Free Radical Scavenging Capacities of Wheat Antioxidants 17910.4.2 Chelating Activity Against Cu2+ 18410.4.3 Effects of Wheat Antioxidants on Lipid Peroxidation in Liposomes 185CHAPTER 11 ANALYSIS OF TOCOPHEROLS AND CAROTENOIDS IN WHEAT MATERIALS USING LIQUID CHROMATOGRAPHY–MASS SPECTROMETRY TECHNOLOGY 19011.1 Introduction 19011.2 Terminology 19311.3 Analysis of Tocopherols and Carotenoids by LC-MS Technology 19311.3.1 Liquid–Liquid Extraction 19411.3.2 Chromatographic Separation 19711.3.3 LC–MS Interfaces and MS Detection 20111.4 Summary 204CHAPTER 12 QUANTIFICATION OF PHENOLIC ACIDS IN WHEAT AND WHEAT-BASED PRODUCTS 20812.1 Introduction 20812.2 Background 20912.3 Chemicals and Equipments 20912.4 Methods 21012.4.1 Sample Preparation 1 21012.4.2 Sample Preparation 2 According to the Protocol Reported by Kim et al. (Fig. 12.2) 21112.4.3 HPLC Separation and Determination 21312.5 Discussion 213CHAPTER 13 EFFECTS OF WHEAT ON NORMAL INTESTINE 21913.1 Introduction 21913.2 Wheat Component Effects on Normal Intestinal Epithelial Cells in vitro 22013.2.1 Background Information 22013.2.2 Effects of Wheat Bran Extract on IEC-6 Cell Proliferation 22213.2.3 Ferulic Acid and IEC-6 Cell Proliferation 22413.3 Discussion 23213.4 Conclusion 234CHAPTER 14 WHEAT ANTIOXIDANTS AND CHOLESTEROL METABOLISM 23614.1 Introduction 33614.2 Wheat Antioxidants 23614.2.1 Phenolic Acids 23714.2.2 Carotenoids 23714.2.3 Tocopherols 23714.3 Wheat Antioxidant Properties 23814.4 Cholesterol Homeostasis 23914.5 Effects of Wheat Antioxidants on Cholesterol Metabolism 24014.6 Summary 241CHAPTER 15 WHEAT ANTIOXIDANT BIOAVAILABILITY 24415.1 Introduction 24415.2 Absorption Characteristics of Fluorescein In Vitro 24515.3 Absorption Characteristics of Phenolic Acid In Vitro 24715.3.1 FA and PCA 24715.3.2 CA, CLA, GA, and RA 24815.3.3 Artepillin C (AC) 24915.4 Absorption Efficiency and Bioavailability of Phenolic Acid in Rats 25115.5 Absorption Characteristics of Colonic Metabolites of Poorly Absorbed Polyphenols In Vitro 25315.6 Current Knowledge and Status of the MCT-Mediated Transport System 25615.6.1 Gastric Absorption 25615.6.2 MCT Subtype Responsible for Transport of PAs and Microbial Metabolites of Polyphenols 25615.6.3 Concept of Metabonutrients 25715.7 Overview of Absorption and Bioavailability of Wheat Antioxidants: Future Studies 25815.7.1 SRA, SPA, VA and PBA 25815.7.2 Free, Soluble Conjugate, and Insoluble Bound PAs in Wheat 259CHAPTER 16 WHEAT LIGNANS: PROMISING CANCER PREVENTIVE AGENTS 26416.1 Introduction 26416.2 Lignans and Cancer Prevention 26616.2.1 Epidemiological and Clinical Studies 26716.2.2 Experimental Animal Studies 26716.3 Plausible Mechanisms of Lignans for Cancer Prevention 268INDEX