Handbook of Vanilla Science and Technology

An updated guide to the production, science, and uses of vanilla  Vanilla is a flavor and fragrance in foods, cosmetics, pharmaceuticals, and a wealth of other products. Now in its second edition, the Handbook of Vanilla Science and Technology provides a comprehensive and updated review of the science and technology used in these items’ production and supply.  Featuring contributions from an international range of experts, this revised edition covers a multitude of topics, including agricultural production, global markets, analytical methods, sensory analysis, food and fragrance applications, organic farming and fair trade, botanical diseases, and novel uses.  The Handbook of Vanilla Science and Technology, Second Edition is a vital resource for producers, distributors, and scientists involved in vanilla’s growth and utilization, and offers readers: A guide to the cultivation, extraction, analysis, DNA sequencing, and marketing of vanilla Information on the production of vanilla in a range of countries such as Mexico, Australia, Costa Rica, and India Guidelines on the quality control of vanilla beans and extracts Information on fair trade and the future of vanilla

Table of Contents:
List of Contributors xix Preface xxiii Part I Production of Vanilla – Agricultural Systems and Curing 1 1 Mexican Vanilla Production 3 Juan Hernandez‐Hernández 1.1 Introduction 3 1.1.1 The Mexican Vanilla Legend 4 1.2 Cultivation Methods 5 1.2.1 “Traditional”/Acahual 5 1.2.2 Intensive System (Monoculture) 6 1.2.3 Vanilla Cultivation in Existing Orange Groves 6 1.2.4 Shade Houses 7 1.3 Vanilla Propagation Techniques 8 1.3.1 Preparation and Disinfection of Cuttings 8 1.3.2 Establishing Cuttings – Timing 8 1.3.3 Establishing Cuttings – Planting 9 1.3.4 New Bud Formation and Root Growth 9 1.4 Irrigation 9 1.5 Nutrition 10 1.5.1 Mulch 10 1.5.2 Building Compost 10 1.6 Weed Control 11 1.7 Shade Management (Pruning of Support Trees) 11 1.8 Shoot Management – Looping 12 1.9 Shoot Management – Rooting 12 1.10 Main Vanilla Insect Pest 12 1.11 Main Vanilla Diseases 13 1.11.1 Anthracnose 14 1.11.2 Rust 14 1.11.3 Yellowing and Pre‐mature Fruit Drop 14 1.12 Flowering and Pollination 14 1.12.1 Percent of Flowering Plants 15 1.12.2 Natural Pollination 15 1.12.3 Hand Pollination 15 1.12.4 Quantity of Flowers to be Pollinated 17 1.12.5 Fruit Development 17 1.13 Harvesting 17 1.13.1 Harvesting Practices 18 1.13.2 Preventing Theft 18 1.14 Green Vanilla Commercialization 19 1.14.1 Prices 19 1.15 Curing 19 1.15.1 Yield Ratio of Green/Cured Vanilla 21 1.16 Grading 21 1.16.1 Packing 22 1.17 Buyers 23 1.18 Export Volume 23 1.19 Prices 23 1.20 Aromatic Profile 23 1.21 Summary 24 References 24 2 Vanilla Diseases 27 Juan Hernandez‐Hernández 2.1 Introduction 27 2.2 Root and Stem Rot (Fusarium oxysporum f. Sp. Vanillae) 27 2.2.1 Description 27 2.2.2 Damage 28 2.2.3 Control 28 2.3 Black Rot (Phytophtora Sp.) 29 2.3.1 Description 29 2.3.2 Damage 29 2.3.3 Control 29 2.4 Anthracnose (Colletotrichum Sp.) 30 2.4.1 Description 30 2.4.2 Damage 31 2.4.3 Control 31 2.5 Rust (Uromyces Sp.) 31 2.5.1 Description 31 2.5.2 Damage 2.5.3 Control 32 2.6 Rotting of Recently Planted Cuttings 32 2.6.1 Description 32 2.6.2 Damage 32 2.6.3 Control 33 2.7 Yellowing and Shedding of Young Fruits 33 2.7.1 Description 33 2.7.2 Damage 34 2.7.3 Control 34 2.8 Viral Diseases 35 2.8.1 Cymbidium Mosaic Virus (CYMV) 35 2.8.2 Vanilla Mosaic Virus (VMV) 35 2.8.3 Vanilla Necrosis Potyvirus (VNPV) 35 2.8.4 Odontoglossum Ringspot Virus (ORSV) 35 2.8.5 Prevention of Viral Diseases 36 2.9 Damage by Adverse Climatic Factors 36 2.9.1 Natural Pruning of the Apical Buds 36 2.9.1.1 Description 36 2.9.1.2 Damage 37 2.9.1.3 Control 37 2.10 Damage from Sunburn 37 2.10.1 Description 37 2.10.2 Damage 37 2.10.3 Control 38 2.11 Hurricanes 38 References 39 3 Vanilla Production in Costa Rica 41 Elida Varela Quirós 3.1 Introduction 41 3.2 History of Vanilla Production in Costa Rica 42 3.2.1 The First Phase of Large‐scale Cultivation in Costa Rica 42 3.2.2 The Second Phase of Vanilla Cultivation in Costa Rica 42 3.2.3 The Third Phase 43 3.3 Vanilla Production – The Traditional System 45 3.4 Vanilla Production – The Intensive System 47 3.5 Propagation 48 3.6 Diseases and Pests 49 3.7 Vanilla Bean Processing 50 3.8 Conclusions 50 References 51 4 Atypical Flowering of Vanilla planifolia in the Region of Junín, Peru 53 Juan Hernández-Hernández 4.1 Preparation of the “Mother” Plant (Cuttings) 54 4.2 Planting Method 54 4.2.1 Weed Control 55 4.2.2 Shoot Management – Looping 55 4.2.3 Shoot Management – Rooting 55 4.3 Nutrition 55 4.4 Irrigation 55 4.5 Pests, Disorders, and Diseases 57 4.5.1 Vanilla Pest 57 4.5.2 Diseases 57 4.5.3 Intense Solar Radiation 57 4.5.4 New Pest 57 4.5.5 New Disease 58 4.6 Flowering Period 59 4.6.1 Atypical Vanilla Bloom in Peru 59 4.7 Hand Pollination 60 4.8 Harvesting 61 4.9 Vanilla Curing 62 4.10 Final Comments 62 References 63 5 Vanilla Production in the Context of Culture, Economics, and Ecology of Belize 65 Nelle Gretzinger and Dawn Dean 5.1 Introduction 65 5.1.1 Toledo Agriculture and Socio‐demographics Today 66 5.1.2 Maya Mountain Research Farm 66 5.1.3 Agro‐ecological Systems 67 5.1.4 Maya Mountain Research Farm Vanilla Cultivation and Introduction Project 68 5.1.5 The Belize Organic Vanilla Association 69 5.1.6 OVA Description and Goals 69 5.1.7 Innovative Vanilla Plantation Establishment Method Pioneered by OVA Members Nicasio and Ophelia Chee Sanchez 71 5.1.8 Wild/Relic Vanilla Stands in Toledo District 72 5.1.9 Possibility of Wild Superior or Useful Genotypes/Species 74 5.1.10 Dr Pesach Lubinsky’s Research in Belize and Regarding Vanilla tahitensis 74 5.1.11 Manche Chol 76 5.2 Discussion 78 Acknowledgments 79 References 82 6 Conservation and Sustainable Use of Vanilla Crop Wild Relatives in Colombia 85 Nicola S. Flanagan, Paul Chavarriaga, and Ana Teresa Mosquera‐Espinosa 6.1 Introduction 85 6.1.1 Low Genetic Diversity in the Vanilla Crop 85 6.1.2 The Importance of Crop Wild Relatives for Agriculture 85 6.2 Vanilla Crop Wild Relatives 86 6.2.1 Phylogenetic Diversity Within the Genus Vanilla 86 6.2.2 The Secondary Gene Pool for Vanilla 86 6.2.3 Vanilla Diversity in Colombia 87 6.3 Vanilla Species in the Wild 89 6.3.1 Vanilla Species are Rare in the Wild 89 6.3.2 Reproductive Biology of Vanilla Wild Species 91 6.3.2.1 Pollinators 91 6.3.2.2 Autogamy 91 6.3.3 Mycorrhizal Interactions 92 6.3.4 Further Interactions with the Microbiome 93 6.3.5 Bioclimatic and Biophysical Adaptations 94 6.4 Conservation of Vanilla Crop Wild Relatives 95 6.4.1 Threats to Conservation 95 6.4.2 Conservation In situ 96 6.4.3 Conservation Ex situ 96 6.4.4 Conservation Ex situ of the Vanilla Microbiome 98 6.4.5 Conservation of Circa situm and Sustainable Use 98 6.5 Biotechnological Approaches for Vanilla Genetic Resource Conservation and Utilization 100 6.5.1 Characterization and Utilization of Genetic Diversity 100 6.5.1.1 DNA Barcoding 100 6.5.1.2 Genomic Characterization of Vanilla 100 6.5.2 Application of Microorganisms in Vanilla Cultivation 101 6.6 An Integrated Strategy for Conservation and Sustainable Use of Vanilla Crop Wild Relatives 101 6.6.1 A Colombian National Strategy for Vanilla CWR 101 6.6.2 International Strategy for Conservation of Vanilla CWR 102 References 102 7 The History of Vanilla in Puerto Rico: Diversity, Rise, Fall, and Future Prospects 111 Paul Bayman 7.1 Introduction 111 7.2 Diversity of Wild Vanilla in Puerto Rico 111 7.2.1 Species and Distributions 111 7.2.2 Flowering, Pollination, and Fruit Set 112 7.3 Rise and Fall: The History of Vanilla Cultivation in Puerto Rico 112 7.4 Socioeconomic Factors Contributing to the Decline of Vanilla 114 7.5 Diseases and Decline 114 7.5.1 Fusarium Root and Stem Rot (RSR) 115 7.5.1.1 The Pathogen 115 7.5.1.2 Symptoms of RSR 116 7.5.1.3 Other Fusarium Species 116 7.5.2 Other Diseases and Pests 116 7.5.3 Possible Solutions to RSR 116 7.5.3.1 Biological Control 116 7.5.3.2 Mycorrhiza 117 7.5.3.3 Chemical Control 117 7.5.3.4 Breeding 117 7.5.3.5 Cultural Control 117 7.6 Future Prospects 118 Acknowledgments 118 References 118 8 Origins and Patterns of Vanilla Cultivation in Tropical America (1500–1900): No Support for an Independent Domestication of Vanilla in South America 121 Pesach Lubinsky, Gustavo A. Romero‐González, Sylvia M. Heredia, and Stephanie Zabel 8.1 Introduction 121 8.1.1 I. Pre‐Cultivation, ca. 1500–1750s 127 8.1.2 II. Papantla Monopoly, 1760s–1840s 131 8.1.3 III. The Vanilla Revolution, 1850s–1900, “… and we’ve never looked back” 135 8.2 The Vanilla Necklace 136 8.3 Summary 138 Acknowledgments 139 References 139 9 Vanilla Production in Australia 147 Richard Exley 9.1 Introduction 147 9.2 History 147 9.3 Species 148 9.4 Climatic Regions of Australia Suitable for Vanilla 148 9.5 Climatic Conditions in the Vanilla Growing Regions 149 9.6 Soil and Nutrients 150 9.7 Watering 150 9.8 Fertilizing 150 9.9 Propagation 150 9.10 Support 151 9.11 Light/Shade 152 9.12 Spacing 153 9.13 Training 154 9.14 Flowering, Fruit Set, Growth, and Maturation 154 9.14.1 Flowering 154 9.14.2 Fruit Set (Pollination) 154 9.14.3 Growth and Maturation 155 9.15 Harvesting 155 9.16 Curing 155 9.16.1 Overview 155 References 156 10 Vanilla in Dutch Greenhouses: A Discovery – From Research to Production 157 Filip van Noort 10.1 Introduction 157 10.1.1 Start of Research 157 10.2 Review of Literature 157 10.3 Flowering 159 10.3.1 Greenhouse 160 10.3.2 Sustainability 160 10.4 Varieties 161 10.5 Propagation 161 10.5.1 Cultivation 161 10.5.2 Growing Systems 162 10.6 Feasibility and Conclusions 162 References 163 11 Establishing Vanilla Production and a Vanilla Breeding Program in the Southern United States 165 Alan H. Chambers 11.1 Introduction 165 11.2 Southern Florida Climate 165 11.2.1 Average Temperatures 166 11.2.2 Average Rainfall 166 11.2.3 Average Solar Radiation 166 11.2.4 Major Weather Events 168 11.3 Native and Naturalized Vanilla Species of South Florida 169 11.3.1 V. dilloniana 169 11.3.2 V. mexicana 169 11.3.3 V. barbellata 169 11.3.4 V. phaeantha 169 11.3.5 V. planifolia 171 11.4 Establishing Vanilla Production in Southern Florida 173 11.4.1 Shade House Cultivation 173 11.4.2 Tutor Tree Cultivation 173 11.4.3 Substrate Considerations 174 11.4.4 Local Economics and Niche Opportunities 174 11.5 Vanilla Breeding 175 11.5.1 Establishing a Vanilla Breeding Program in the United States 175 11.5.2 Acquiring Diverse Vanilla Accessions 176 11.5.3 Creating Diversity in Vanilla 176 11.5.4 Identifying the Primary Gene Pool 177 11.5.5 Target Traits 177 11.5.6 A Case for a Publically Available Vanilla Genome 178 11.6 Conclusions 178 References 178 12 In vitro Propagation of Vanilla 181 Rebeca Alicia Menchaca García 12.1 Methods 182 12.1.1 In vitro Germination 182 12.1.2 Tissue Culture 182 12.2 Results and Discussion 183 12.2.1 Germination 183 12.2.2 Seed Maturity 183 12.2.3 Time for Germination 183 12.2.4 Scarification 183 12.2.5 Tissue Culture 183 12.2.6 Hybridization 184 12.2.7 In vitro Germplasm Bank 185 12.2.8 Repatriation and Recovery of Mexican Species 185 12.2.9 Method of Ex vitro Adaptation 186 12.2.10 Greenhouse Collection 186 12.2.11 Social Linkage 186 12.2.12 Human Resource Training and International Interaction 187 12.3 Conclusions 187 References 188 13 Curing of Vanilla 191 Chaim Frenkel, Arvind S. Ranadive, Javier Tochihuitl Vázquez, and Daphna Havkin‐Frenkel 13.1 Introduction 191 13.2 Botany of the Vanilla Pod 192 13.2.1 Two Fruit Regions 192 13.2.2 Fruit Components 192 13.2.3 Fruit Anatomy 193 13.2.4 Pollination Initiates Ovary and Fruit Development 193 13.2.5 Mature Fruit 194 13.3 On‐the‐vine Curing Process in a Vanilla Pod 195 13.4 Off‐the‐vine Curing Process of Vanilla Beans 196 13.4.1 Purpose of Curing 198 13.4.2 Traditional Methods of Curing 199 13.4.2.1 Killing 199 13.4.2.2 Sweating 200 13.4.2.3 Drying and Conditioning 201 13.5 Activity of Hydrolytic Enzymes Occurring in a Curing Vanilla Pod 202 13.5.1 Protease Activity 202 13.5.2 Cell Wall Hydrolyzing Enzymes 204 13.5.3 Glycosyl Hydrolases 204 13.6 Activity of Oxidative Enzymes Occurring in a Curing Vanilla Pod 209 13.7 Vanilla Products 212 13.8 Summary and Conclusions 212 13.9 Addendum: Commercial Curing Methods of Green Vanilla Bean 213 13.9.1 Traditional Methods 213 13.9.1.1 Mexican Curing Method 213 13.9.1.2 The Bourbon Curing Method 214 13.9.1.3 The Tahitian Curing Method 214 13.9.1.4 Other Traditional Curing Methods 214 13.9.1.5 Indonesian Curing of Vanilla Bean 215 13.9.2 Refinement of Traditional Curing Methods 215 13.9.3 Novel Curing Methods 215 References 216 14 Fair Trade – The Future of Vanilla? 223 Richard J. Brownell Jr 14.1 The Crisis 223 14.2 The Farmer 224 14.3 Fast Forward 226 14.4 Fair Trade – Background 226 14.4.1 Fair Trade Principles 227 14.4.2 Vanilla and Fair Trade 228 14.5 Commodity Cycles 229 14.6 Issues 230 14.6.1 The Price Differential 230 14.6.2 Vanilla Quality 231 14.6.3 Limited Availability 231 14.6.4 Ensuring that Farmers are Paid the FT Price 232 14.6.5 Consumer Acceptance 232 14.7 Conclusions 233 14.7.1 Update 2017 – Fair Trade Vanilla: Today 233 14.7.2 Update 2017 – Fair Trade Vanilla: The Future 234 Part II Authentication and Flavor Analysis 237 15 Quality Control of Vanilla Beans and Extracts 239 Arvind S. Ranadive 15.1 Introduction 239 15.2 Quality Control of Vanilla Beans 239 15.2.1 Grading of Vanilla Beans 240 15.2.1.1 Vanilla Grading in Mexico 241 15.2.1.2 Vanilla Grading in Madagascar 241 15.2.1.3 Vanilla Grading in Indonesia 241 15.2.1.4 Vanilla Grading in Uganda 241 15.2.1.5 Vanilla Grading in Tahiti 242 15.2.2 Aroma of Vanilla Beans 243 15.2.3 Moisture Content of Vanilla Beans 246 15.2.4 Vanillin Content 246 15.2.4.1 Vanilla Bean Extraction 247 15.2.4.2 Vanillin Determination 247 15.2.4.3 Vanillin Determination in Vanilla Extracts and Other Vanilla Products 248 15.2.4.4 HPLC Method 248 15.2.5 Microbial Contaminant Limits 249 15.3 Quality Control of Commercial Vanilla Products 249 15.3.1 Definition of Vanilla Products 249 15.3.1.1 Vanilla Extracts 249 15.3.1.2 Vanilla Flavoring 250 15.3.1.3 Vanilla‐Vanillin Extract and Flavoring 250 15.3.1.4 Concentrated Vanilla Extract and Flavoring 250 15.3.1.5 Vanilla Oleoresin 250 15.3.1.6 Vanilla Absolute 250 15.3.1.7 Vanilla Powder And Vanilla‐Vanillin Powder 251 15.3.1.8 Vanilla Tincture for Perfumery 251 15.3.2 Vanilla Extract Quality Parameters 251 15.3.2.1 Appearance: Color and Clarity 251 15.3.2.2 Flavor 251 15.3.2.3 Soluble Solids Content 252 15.3.2.4 Vanillin Content 252 15.3.2.5 Organic Acids – (Wichmann) Lead Number 253 15.3.2.6 Resin Content 253 15.3.2.7 Microbial Limits 253 15.4 Determination of Authenticity of Vanilla Extracts 254 15.4.1 Guidelines for Determination of Authenticity 254 15.4.1.1 Evaluation of the Ratios Between Specific Components 255 15.4.1.2 Isotope‐ratios Mass Spectrometry 255 15.4.1.3 Site‐specific Quantitative Deuterium NmR 255 15.4.2 Other Methods to Determine Authenticity 256 15.4.2.1 Stable Isotope Ratio Analysis (SIRA) 256 15.4.2.2 SNIF‐NMR Technique 258 15.5 Summary 259 Acknowledgment 259 References 259 16 Flavor, Quality, and Authentication 261 Patrick G. Hoffman and Charles M. Zapf 16.1 Introduction 261 16.2 Vanilla Flavor Analyses 262 16.3 Biochemistry and Genetic Research on Vanilla 266 16.4 Vanilla Quality and Authentication Analyses 267 16.4.1 Liquid Chromatographic Methods 268 16.4.2 Isotopic Techniques 272 16.4.3 Radiometric and Stable Isotope Ratio Analysis 272 16.4.4 Nuclear Magnetic Resonance (NMR) 274 16.4.5 Isotopic Techniques Summary 274 16.4.6 Integrated and Miscellaneous Methodologies 275 16.5 Conclusion 277 References 279 17 Volatile Compounds in Vanilla 285 Stephen Toth, Keun Joong Lee, Daphna Havkin‐Frenkel, Faith C. Belanger, and Thomas G. Hartman 17.1 Lexicon of Vanilla Aroma/Flavor Descriptors 285 References 345 18 A Comprehensive Study of Composition and Evaluation of Vanilla Extracts in US Retail Stores 349 Daphna Havkin‐Frenkel, Faith C. Belanger, Debra Y.J. Booth, Kathryn E. Galasso, Francis P. Tangel, and Carlos Javier Hernández Gayosso 18.1 History 349 18.2 Uses of Vanilla in the Industry 349 18.2.1 Household Products 350 18.2.2 Dairy Products 350 18.2.3 Ice Cream (Frozen Dairy Products) 350 18.2.4 Yogurt 350 18.2.5 Puddings 351 18.2.6 Chocolate 351 18.2.7 Confections 351 18.2.8 Baked Goods 351 18.2.9 Beverages 351 18.2.10 Pet Products 352 18.2.11 Pharmaceutical Products 352 18.2.12 Oral Care 352 18.2.13 Perfume 352 18.2.14 Toys 352 18.3 Major US Vanilla Companies 353 18.4 Introduction to the Study 353 18.5 Materials and Methods 353 18.6 Results and Discussion 354 18.6.1 Labeling of Retail Vanilla Extracts 354 18.6.2 Flavor Components in the Retail Vanilla Extracts 359 18.6.3 Total Phenol Content of the Retail Vanilla Extracts 363 18.7 Conclusion and Recommendation 363 References 365 19 Vanilla in Perfumery and Beverage Flavors 367 Felix Buccellato 19.1 Earliest Recorded Use of Vanilla 367 Reference 373 Part III Biology of Vanilla 375 20 Vanilla Phylogeny and Classification 377 Kenneth M. Cameron 20.1 Vanilloideae Among Orchids 381 20.2 Diversity Within Vanilloideae 381 20.2.1 Tribe Pogonieae 382 20.2.2 Tribe Vanilleae 383 20.3 Origins and Age of Vanilloideae 384 20.4 Diversity Within Vanilla 385 20.5 Systematic Conclusions and Implications 388 References 389 21 Molecular Analysis of a Vanilla Hybrid Cultivated in Costa Rica 391 Faith C. Belanger and Daphna Havkin‐Frenkel 21.1 Methods 392 21.1.1 PCR Amplification, Cloning, and DNA Sequencing 392 21.1.2 Phylogenetic Analysis 393 21.1.3 Preparation of Vanilla Extracts 393 21.2 Results and Discussion 393 References 399 22 Root Cause: Mycorrhizal Fungi of Vanilla and Prospects for Biological Control of Root Rots 403 Paul Bayman, María del Carmen A. Gonzalez‐Chávez, Ana T. Mosquera‐Espinosa, and Andrea Porras‐Alfaro 22.1 Introduction 403 22.1.1 Orchids and Their Mycorrhiza 403 22.1.2 The Fungi: Rhizoctonia and Related Taxa 404 22.2 Phylogenetic Diversity of Mycorrhizal Fungi of Vanilla 406 22.2.1 Methods 406 22.2.2 Diversity of Mycorrhizal Fungi 408 22.2.3 Fusarium 409 22.2.4 Distribution of Mycorrhiza and Colonization of Roots 409 22.2.5 Roots in Soil vs. Roots on Bark 410 22.2.6 Differences in Mycorrhiza Among Agrosystems 410 22.2.7 Limitations of Methods and Sources of Bias 410 22.3 Mycorrhizal Fungi of Vanilla Stimulate Seed Germination and Seedling Growth 411 22.3.1 Seedling Germination Experiments 411 22.3.2 Seedling Growth and Survival Experiments 411 22.4 Can Mycorrhizal Fungi Protect Vanilla Plants from Pathogens? 414 22.4.1 Biocontrol of Plant Diseases Using Arbuscular Mycorrhizal Fungi 414 22.4.2 Biocontrol of Plant Diseases Using Ceratobasidium 415 22.4.3 Are Rhizoctonia Strains Used for Biocontrol also Potential Pathogens? 416 22.4.4 Fusarium Species as Potential Biocontrol Agents to Protect Vanilla from Fusarium oxysporum Root Rots 417 22.5 Conclusions 417 References 418 23 Enzymes Characterized From Vanilla 423 Andrzej Podstolski 23.1 L‐Phenylalanine Ammonia‐Lyse (Pal) and Cinnamate‐4‐Hydroxylase (C4h) 423 23.2 Chain-shortening Enzymes 424 23.3 4‐Coumaric Acid 3‐Hydroxylase (C3H) 427 23.4 O‐Methyltransferase (OMT) 428 23.5 Benzyl Alcohol Dehydrogenase (Bad) 428 23.6 Glycosyltransferases (GTS) 429 23.7 β‐Glycosyl Hydrolases and Curing 430 References 431 24 Vanillin Biosynthesis – Still not as Simple as it Seems? 435 Richard A. Dixon 24.1 Introduction 435 24.2 Multiple Pathways to Vanillin Based on Biochemistry? 438 24.3 Elucidation of Vanillin Biosynthesis via Molecular Biology? 440 References 442 25 Vanilla planifolia – The Source of the Unexpected Discovery of a New Lignin 447 Fang Chen and Richard A. Dixon 25.1 Introduction 447 25.2 Identification of C‐lignin in V. planifolia 449 25.3 Identification of Genes Potentially Involved in Lignin and Vanillin Biosynthesis 451 25.4 C‐Lignin Biosynthesis in Other Plants 452 25.5 Commercial Value of C‐Lignin as a Novel Natural Polymer 453 References 454 Part IV Biotechnological Production of Vanillin 457 26 Biotechnology of Vanillin: Vanillin from Microbial Sources 459 Ivica Labuda 26.1 Introduction 459 26.1.1 Why? 459 26.1.2 How? 460 26.2 Substrates 460 26.2.1 Ferulic Acid (4‐Hydroxy 3‐Methoxy Cinnamic Acid) 460 26.2.1.1 Non‐β‐oxidative Deacetylation (CoA‐dependent) 462 26.2.1.2 β‐Oxidative Deacetylation (CoA‐Dependent) 463 26.2.1.3 Non‐Oxidative Decarboxylation 464 26.2.1.4 CoA‐Independent Deacetylation 465 26.2.1.5 Side‐Chain Reductive Pathway 466 26.2.2 Eugenol and Isoeugenol 467 26.2.3 Lignin 468 26.2.4 Sugars 469 26.3 Microorganisms 470 26.3.1 Bacteria 470 26.3.1.1 Pseudomonas 470 26.3.1.2 Streptomyces 470 26.3.1.3 Bacillus 471 26.3.1.4 Corynebacterium 472 26.3.1.5 Escherichia coli 472 26.3.1.6 Amycolatopsis sp. 473 26.3.1.7 Lactic Acid Bacteria (LAB) 473 26.3.1.8 Clostridium 474 26.3.2 Fungi and Yeasts 474 26.4 Processes 477 26.4.1 Direct Bioconversion Process 477 26.4.2 Bi‐Phasic Fermentation 480 26.4.3 Mixed Culture Fermentation 480 26.4.4 Continuous Fermentation with Immobilized Cells 481 26.4.5 Enzymes 481 26.4.6 Cofactors 482 26.5 Downstream Processing and Recovery 482 26.6 Conclusions 482 References 483 Index 489

About the Author :
Dr. Daphna Havkin-Frenkel, Department of Plant Biology, School of Environmental and Biological Sciences, Rutgers University, New Brunswick, New Jersey, USA. Dr. Faith C. Belanger, Department of Plant Biology, School of Environmental and Biological Sciences, Rutgers University, New Brunswick, New Jersey, USA.