Modern Methods of Plant Analysis When the handbook Modern Methods of Plant Analysis, was first introduced in 1954, the considerations were: 1. the dependence of scientific progress in biology on the improvement of existing and the introduction of new methods; - 2. the difficulty in finding many new analytical methods in specialized journals which are normally not accessible to experimental plant biologists; 3. the fact that in the methods sections of papers the description of methods is frequently so compact, or even sometimes to incomplete, that it is difficult to reproduce experiments. These considerations still stand today. The series was highly successful, seven volumes appearing between 1956 and 1964. Since there is still today a demand for the old series, the publisher has decided to resume publication of Modern Methods of Plant Analysis. It is hoped that the New Series will be just as acceptable to those working in plant sciences and related fields as the early volumes undoubtedly were. It is difficult to single out the major reasons for the success of any publication, but we believe that the methods published in the first series were up-to-date at the time and presented in a way that made description, as applied to plant material, complete in itself with little need to consult other publications. Contribution authors have attempted to follow these guidelines in this New Series of volumes. Editorial The earlier series of Modern Methods of Plant Analysis was initiated by Michel v.

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Non-Intrusive Fruit and Plant Analysis by Laser Photothermal Measurements of Ethylene Emission.- 1 Introduction.- 2 The Photothermal Deflection Method.- 2.1 The Experimental Setup.- 2.2 Practical Considerations.- 2.3 Local and Fast Ethylene Detection.- 2.3.1 Ethylene Emission Pathways for Intact Cherry Tomatoes.- 2.3.2 Locally Wounded Tomato Tissue.- 3 Photoacoustics Using a CO2 Laser.- 3.1 The Experimental Setup.- 3.2 Practical Considerations.- 3.3 Ethylene Emission Rates for Various Species.- 3.3.1 Local Ethylene Emission by Bell Pepper.- 3.3.2 Periodic Anoxic and Aerobic Conditions for Cherry Tomatoes.- 3.3.3 Germinating Peas Periodically Fumigated with Ozone.- 3.3.4 Rumex palustris Exposed to Flooding Stress.- 4 Photoacoustics Using a CO Laser.- 4.1 The Experimental Setup.- 4.2 Practical Considerations.- 5 Résumé.- References.- Induction of Fruit Aroma and Quality by Post-Harvest Application of Natural Metabolites or Anaerobic Conditions.- 1 Biosynthesis and Degradation of Aroma Volatiles in Fruits During Post-Harvest Life.- 1.1 Ripening and Aroma Production in Fruits.- 1.2 Measurements of Sensory Quality.- 2 Induction of Aroma Volatile Production by Application of Aldehydes, Alcohols and Acids.- 2.1 Application of Acetaldehyde.- 2.2 Biosynthesis of Aroma Volatiles from Various Precursors.- 2.3 Flavour and Taste Enhancement.- 2.4 Effect of Acetaldehyde on Sugar and Acid Content.- 2.5 Volatile Formation in Vitro.- 2.6 Fungicidic Activity of Aldehydes.- 2.7 Disadvantages of Exogenous Application of Metabolites.- 3 Induction of Aroma Volatile Production by Pre-Storage Under Anaerobic Conditions.- 3.1 Application of Anaerobiosis.- 3.2 Induction of Volatile Formation.- 3.3 Removal of Astringency.- 3.4 Changes in Sugar and Acidity.- 3.5 Injury and Off-Flavour Production.- 4 Conclusion.- References.- The Analysis of Flavouring Compounds in Grapes.- 1 Introduction.- 2 Methoxypyrazines.- 2.1 Isolation and Characterization.- 2.2 Quantitative Analysis.- 2.2.1 Principles of Trace Organic Analysis.- 2.2.2 Quantitative Methoxypyrazine Analysis.- 2.3 Methods.- 2.3.1 Methoxypyrazine Standards.- 2.3.2 Instrument Calibration.- 2.3.3 Isolation of Methoxypyrazine Components.- 2.3.4 Determination of Standard Response.- 2.3.5 Mass Spectrometry of Methoxypyrazine Isolates.- 2.4 Sensory Characteristics.- 2.5 Viticultural Influences.- 2.6 Varietal Differences.- 3 Glycosidically Bound Flavour Compounds of Grapes.- 3.1 Isolation of Glycosidic Precursors.- 3.2 Analysis of Intact Glycosides.- 3.2.1 Gas Chromatography.- 3.2.2 High Performance Liquid Chromatography (HPLC) and Other Liquid-Solid Chromatographic Methods.- 3.2.3 Countercurrent Chromatographic Methods.- 3.2.4 Mass Spectrometry.- 3.3 Analysis After Hydrolysis of Glycosides.- 3.3.1 Enzyme Hydrolysis.- 3.3.2 Compositional Analysis of Volatile Aglycones.- 3.3.3 Sensory Analysis of Aglycones.- 3.4 Application of Flavour Precursor and Aglycone Compositional Analysis Data to Grape and Wine Characterization.- 3.5 Effects on Wine Aroma Resulting from Precursor Hydrolysis.- 4 Conclusion.- References.- Analysis of Bitter Principles in Citrus.- 1 Introduction.- 2 Limonoid Bitterness.- 2.1 Limonoid Aglycone Analysis.- 2.1.1 Sample Preparation.- 2.1.2 Thin-Layer Chromatography.- 2.1.3 High-Performance Liquid Chromatography.- 2.1.4 Radioimmunoassay (RIA).- 2.1.5 Enzyme-Linked Immunoassay (EIA).- 2.2 Sources of Limonoid Standards.- 3 Flavonoid Bitterness.- 3.1 Analysis of Flavonoid Bitter Principles.- 3.1.1 Sample Preparation.- 3.1.2 Colorimetric and Spectrophotometric Methods.- 3.1.3 Thin-Layer Chromatography.- 3.1.4 High-Performance Liquid Chromatography.- 3.1.5 Radioimmunoassay (RIA) and Enzyme-Linked Immunoassay (ELISA or EIA).- 3.1.6 Capillary Electrophoresis.- 3.1.7 Gas Chromatography-Mass Spectroscopy.- 3.2 Sources of Flavonoid Standards.- References.- Phenolic Content and l-Phenylalanine Ammonia-Lyase Activity In Peach Fruit.- 1 Introduction.- 2 Phenolic Content and Phenolic Composition of Peach Fruit.- 2.1 Analysis of Phenolic Compounds.- 2.1.1 Total and High-Molecular-Weight Phenolics.- 2.1.2 Condensed Tannins.- 2.1.3 Phenolic Composition.- 2.2 Relationship Between Degree of Astringency Based on Organoleptic Tests and Phenolic Content.- 3 PAL Activity in Peach Fruit.- 3.1 General Phenylpropanoid Metabolism.- 3.2 PAL Extraction and Assay.- 3.2.1 Extraction and Purification.- 3.2.2 Spectrophotometric Assay.- 3.2.3 Radiochemical Assay with [14C] Phenylalanine.- 3.3 Relationships Between Phenolic Content, PAL Activity, and l-Phenylalanine Content.- 4 Factors Affecting Phenolic Content and PAL Activity in Peach Fruit.- 4.1 Inherent Factors.- 4.2 Environmental Factors.- 4.3 Other Factors.- 5 Concluding Remarks.- References.- Astringency in Persimmon.- 1 Introduction.- 2 Persimmon Tannin.- 2.1 Chemical Structure.- 2.2 Differences Among Fruit Types.- 3 Analytical Methods.- 3.1 Tannin Print Method.- 3.2 Folin-Denis Method.- 3.3 Analysis of Total Tannins.- 4 Quantitative Changes in Tannins.- 4.1 Fruit Development.- 4.2 Removal of Astringency.- 5 Notes on Analytical Methods.- References.- Analysis of Fresh and Dried Apricot.- 1 Introduction.- 2 Fresh Apricot Assessment.- 2.1 Determination of Fruit Size.- 2.2 Determination of Fruit Firmness.- 2.2.1 Procedure - Hand-Held Penotrometers.- 2.2.2 Procedure - Instron Universal Testing Instrument.- 2.2.3 Non-Destructive Firmness Test.- 2.3 Determination of Total Soluble Solids (TSS).- 2.3.1 Sample Preparation for Tests.- 2.3.2 Procedure - Hydrometer.- 2.3.3 Procedure - Refractometer.- 2.4 Sugar.- 2.4.1 Determination of Glucose and Fructose.- 2.4.2 Determination of Sucrose by Invertase Hydrolase.- 2.5 Acidity.- 2.5.1 Determination of Total Titratable Acidity.- 2.5.2 pH.- 2.6 Determination of Juice Viscosity.- 2.7 Colour.- 2.7.1 Colour Comparators.- 2.7.2 Light Reflectance Meters.- 2.8 Determination of Pectic Acid.- 2.9 Determination of Starch.- 3 Dried Apricots.- 3.1 Size.- 3.2 Determination of Drying Ratio.- 3.3 Determination of Moisture.- 3.3.1 Vacuum Oven.- 3.3.2 Infra-Red Moisture Meter.- 3.4 Colour.- 3.4.1 Apricot Colour Extraction.- 3.5 Sulphur Dioxide.- 3.5.1 Sulphur Content of Freshly Sulphured Apricots.- 3.5.2 Sulphur Content of Apricots after Drying.- 3.5.3 Modified Monier-William SO2 Method.- 3.6 Storage Life.- References.- Almond Nut Analysis.- 1 Introduction.- 1.1 Determination of Oil Content and Fatty Acid in Almond Kernels.- 1.2 Introduction.- 1.3 Total Oil Determinat…