Theory and Application of Cyclic Voltammetry for Measurement of Electrode Reaction Kinetics.

Antimicrobial properties of tannins

Hydrophilic-interaction chromatography for the separation of peptides, nucleic acids and other polar compounds

Phenolics in Food and Nutraceuticals is the first single-source compendium of essential information concerning food phenolics. This unique book reports the classification and nomenclature of phenolics, their occurrence in food and nutraceuticals, chemistry and applications, and nutritional and health effects. In addition, it describes antioxidant activity of phenolics in food and nutraceuticals as well as methods for analysis and quantification. Each chapter concludes with an extensive bibliography for further reading. Food scientists, nutritionists, chemists, biochemists, and health professionals will find this book valuable.

Phenolics in food and nutraceuticals

Although organic compounds typically constitute a substantial fraction of the fine particulate matter (PM) in the atmosphere, their molecular composition remains poorly characterized. This is largely because atmospheric particles contain a myriad of diverse organic compounds, not all of which extract in a single solvent or elute through a gas chromatograph; therefore, a substantial portion typically remains unanalyzed. Most often the chemical analysis is performed on a fraction that extracts in organic solvents such as benzene, ether or hexane; consequently, information on the molecular composition of the water-soluble fraction is particularly sparse and incomplete. This paper investigates theoretically the characteristics of the water-soluble fraction by splicing together various strands of information from the literature. We identify specific compounds that are likely to contribute to the water-soluble fraction by juxtaposing observations regarding the extraction characteristics and the molecular composition of atmospheric particulate organics with compound-specific solubility and condensibility for a wide variety of organics. The results show that water-soluble organics, which constitute a substantial fraction of the total organic mass, include C2 to C7 multifunctional compounds (e.g., diacids, polyols, amino acids). The importance of diacids is already recognized; our results provide an impetus for new experiments to establish the atmospheric concentrations and sources of polyols, amino acids and other oxygenated multifunctional compounds.

Water-soluble organics in atmospheric particles: A critical review of the literature and application of thermodynamics to identify candidate compounds

New method for quantitative essential oil analysis

Preface. Chapter 1. Hops as a raw material in the brewery 1.1. Occurrence of hops 1.2. Origin and history 1.3. Hop as a botanical species 1.4. Hop as a commercial plant 1.5. References. Chapter 2. The alpha acids 2.1. Structure of the alpha acids 2.2. Composition and importance of the hop alpha acids 2.3. Biogenesis of the hop alpha acids 2.4. Synthesis of the hop alpha acids 2.5. References. Chapter 3. Reduced derivatives of humulone 3.1. Dihydrohumulone 3.2. Tetrahydrohumulone 3.3. Humulohydroquinone-humuloquinone 3.4. 4-Deoxyhumulone 3.5. 2,6-Bis (3-methylbutyl)-4-(3-methylbutanoyl)resorcinol 3.6. 2,4,6-Tris (3-methylbutyl)resorcinol 3.7. References. Chapter 4. Oxidized derivatives of humulone 4.1. Humulinone 4.2. Tricyclodehydro-isohumulone (TCD) 4.3. Compound 47 4.4. Compound 50 4.5. Compound 52 4.6. Compound 53 4.7. Compound 54 4.8. Compound 55 4.9. Compound 57 4.10. Abeo-isohumulones 4.11. Tetronic acid derivative 67 4.12. Volatile oxidation products 4.13. Latest contributions 4.14. References. Chapter 5. The isohumulones 5.1. Structure of the isohumulones 5.2. Formation of the isohumulones 5.3. Interconversion between isohumulones and humulone 5.4. Synthesis of the isohumulones 5.5. Importance of the isohumulones 5.6. References. Chapter 6. Reduced derivatives of the isohumulones 6.1. Dihydro-isohumulones 6.2. Tetrahydro-isohumulones 6.3. Neohydro-isohumulones and neohydro-isocohumulones 6.4. Compound 97 6.5. The rho-isohumulone 6.6. Compound 107 6.7. References. Chapter 7. Oxidized derivatives of the isohumulones 7.1. Non-volatile oxidized derivatives 7.2. Volatile oxidized derivatives 7.3. References. Chapter 8. Transformation and degradation products of the isohumulones 8.1. The allo-isohumulones 8.2. The hydrated allo-isohumulones 8.3. The acetylhumulinic acids 8.4. The humulinic acids and derivatives 8.5 References. Chapter 9. The anti-isohumulones 9.1. Isolation 9.2. Nomenclature 9.3. Structural proofs 9.4. Formation mechanism 9.5. Importance of the anti-isohumulones 9.6. References. Chapter 10. Degradation and derivatives of the anti-isohumulones 10.1. The anti-acetylhumulinic acids 10.2. Deacylated derivatives of the anti-isohumulones 10.3. Special derivatives of the anti-isohumulones 10.4. References. Chapter 11. The beta acids 11.1. Structure of the beta acids 11.2. Composition of the beta acids 11.3. Biogenesis of the beta acids 11.4. Synthesis of the beta acids 11.5. References. Chapter 12. Reduced derivatives of the beta acids 12.1. Hexahydro-beta acids 12.2. 4-Deoxy-alpha acids 12.3. 4-Deoxytetrahydro-alpha acids 12.4. Reduction products of colupulone with zinc : acetic acid : hydrogen chloride 12.5. References. Chapter 13. Oxidized derivatives of the beta acids 13.1. Oxidation with oxygen or auto-oxidation 13.2. Oxidation with chemical oxidants 13.3. References. Chapter 14. Derivatives of the beta acids in acidic and in alkaline conditions 14.1. Treatment with strong acid 14.2 Treatment with weak acid 14.3.

Chemistry and Analysis of Hop and Beer Bitter Acids

Chemical research has shown that the α-acids are the main quality factors of hops and that the bitter taste of hopped beer derives from the iso-α-acids. This has provided the basis for improvements in hop breeding, conditioning, extraction, use, analysis etc. Structural chemical development of hop constituents was completed about ten years ago. At the present moment the accent of chemical research is on analytical aspects, mainly using High Performance Liquid Chromatography.



From the standpoint of the brewery the situation of chemical research is not completely satisfactory, since a clear understanding of the more subtle chemical quality factors of hops and their impact on beer quality is still lacking.



Hops are much more important for beer than is generally estimated, even in brewery circles.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/j.2050-0416.1986.tb04372.x

100 years of hop chemistry and its relevance to brewing

Synthesis and properties of a novel chiral stationary phase for the resolution of amino acid enantiomers

This contribution to the problems of carbohydrate (sugar) column liquid chromatography, evaluates several currently used systems (reversed phase octadecylated silica gel, amino modified silica gel, cation exchangers on polystyrene and on silica gel basis, polyol derivatised silica gel and anion exchange systems). The elution pattern, analysis time, column efficiency and column life time expectancy are considered to be the important points for this comparison. The application of silica gel-based cation exchanger and of polyol derivatised silica gel is new to this field. The comparison and/or evaluation tries to be critical and to come to a conclusion for the choice of a recommended system.

M. Verzele

Papers

New method for quantitative essential oil analysis

Chemistry and Analysis of Hop and Beer Bitter Acids

100 years of hop chemistry and its relevance to brewing

Synthesis and properties of a novel chiral stationary phase for the resolution of amino acid enantiomers

A critical review of some liquid chromatography systems for the separation of sugars