Coffee

1 Introduction.- 1. Origins.- 2. The Coffee Plant.- 2.1. Species and varieties.- 3. Producing Countries.- 3.1. North/Central America.- 3.2. South America.- 3.3. Africa.- 3.4. Asia.- 3.5. Oceania.- 4. Agricultural Practices.- 5. Processing at Origin.- 5.1. Wet processing.- 5.2. Dry processing.- 5.3. Finishing processes.- 6. Roasted Coffee.- 7. Soluble (Instant) Coffee.- 8. Decaffeination.- 9. Composition.- 10. Physiological Effects.- 11. Coffee Quality.- 12. Coffee Substitutes.- References.- 2 Water and Mineral Contents.- 1. Introduction.- 2. Water Content of Green Coffee.- 2.1. Oven methods of determination.- 2.2. Entrainment distillation.- 2.3. Karl Fischer determination.- 2.4. Non-destructive methods.- 2.5. Sorption isotherms.- 3. Water Content of Parchment Coffee.- 4. Water Content of Roasted Coffee.- 4.1. Sorption isotherms.- 5. Water Content of Instant Coffee.- 5.1. Methods of determination.- 5.2. Sorption isotherms.- 5.3. Fusion and collapse temperature.- 6. Water Content of Coffee Extracts.- 6.1. Water activity.- 6.2. Direct determination of solubles content.- 6.3. Specific gravity and refractive index of extracts.- 6.4. Viscosity.- 6.5. Diffusivity.- 6.6. Freezing point depression.- 7. Mineral Content of Green and Roasted Coffee.- 8. Mineral Content of Instant Coffee.- 9. Trace Elements in Coffees.- References.- 3 Carbohydrates.- 1. Carbohydrates of Green Coffee.- 1.1. Low molecular weight sugars.- 1.2. Polysaccharides.- 1.3. Pectins and lignin.- 2. Carbohydrates of Roasted Coffee.- 2.1. Low molecular weight sugars.- 2.2. Polysaccharides.- 2.3. Carbohydrate conversion products.- 3. Carbohydrates of Coffee Brews, Extracts and Instant Coffee.- 3.1. Low molecular weight sugars.- 3.2. Polysaccharides.- 3.3. Carbohydrate conversion products.- 4. Some Physical Properties of Coffee Carbohydrates.- 5. Determination of Carbohydrates.- References.- 4 Nitrogenous Components.- 1. Introduction.- 2. Alkaloids (Caffeine).- 2.1. Caffeine content of green, roasted and instant coffees.- 2.2. Physiological effects of caffeine.- 2.3. Determination of caffeine.- 3. Trigonelline.- 3.1. Determination of trigonelline.- 4. Nicotinic Acid.- 4.1. Levels in green, roasted and instant coffee.- 4.2. Nutritional significance of nicotinic acid in coffee.- 4.3. Determination of nicotinic acid.- 5. Proteins and Free Amino Acids.- 5.1. Proteins.- 5.2. Enzymes.- 5.3. Pigments.- 5.4. Free amino acids.- References.- 5 Chlorogenic Acids.- 1. Introduction and Brief History.- 2. Chlorogenic Acids Nomenclature.- 3. Chemical Synthesis.- 3.1. Preparation of the protected acyl chloride.- 3.2. Preparation of the protected quinic acid.- 3.3. Esterification reactions.- 3.4. Acyl migration as a synthetic method.- 4. Physical Properties.- 4.1. Solubility and partition coefficients.- 4.2. Dissociation constant.- 4.3. Crystal form and melting points.- 4.4. Polarimetric data.- 4.5. Infrared spectra.- 4.6. Mass spectra.- 4.7. Nuclear magnetic resonance spectroscopy.- 4.8. Ultraviolet spectroscopy.- 5. Origin and Function.- 5.1. Biosynthesis.- 5.2. Function.- 6. Chlorogenic Acids Extraction and Analysis.- 6.1. Size reduction.- 6.2. Extraction.- 6.3. Possible artefacts.- 6.4. Chlorogenic acids analysis.- 7. Chlorogenic Acids Content in Green Coffee Beans.- 7.1. Normal commercial coffee beans.- 7.2. Green beans from immature fruit.- 7.3. Discoloured green beans.- 7.4. Stored green beans.- 8. Chlorogenic Acids Content of Roasted Beans and Soluble Powders.- 8.1. Relative loss per gram dry matter loss.- 8.2. Relative loss per unit time.- 8.3. Loss in absolute terms.- 8.4. Fate of the chlorogenic acids.- 9. Organoleptic Properties.- 9.1. Model system studies and structure-activity relationships.- 9.2. Relevance to the acceptability of coffee products and coffee beverage.- 9.3. Chlorogenic acids as predictors and determinants of beverage quality.- References.- 6 Lipids.- 1. Introduction.- 2. Coffee Oil.- 2.1. Determination of total oil content.- 2.2. Isolation of coffee oil for detailed analysis.- 2.3. Free and total fatty acids.- 2.4. Triglycerides.- 2.5. Diterpenes.- 2.6. Sterols.- 2.7. Tocopherols.- 2.8. Other compounds.- 3. Coffee Wax.- 3.1. Determination of the content of C-5-HT in green and roasted coffee.- References.- 7 Volatile Components.- 1. Preamble.- 2. Methodology.- 2.1. Introduction.- 2.2. Headspace methods.- 2.3. Distillation techniqueS.- 2.4. Other techniques.- 2.5. Summary.- 3. The Nature of the Volatile Components of Coffee.- 3.1. Introduction.- 3.2. Green coffee.- 3.3. The roasting process.- 3.4. Roasted coffee.- 3.5. Effect of species on coffee aroma composition.- 3.6. Coffee processing and its effect on volatile composition.- 3.7. Quantitative assessment of coffee volatiles.- 3.8. Summary.- References.- 8 Carboxylic Acids.- 1. The Role of Acids in Infusions.- 1.1. The importance of acidity to taste and flavour.- 1.2. Relationship between pH and acid content.- 2. The Acid Content of Green Coffee.- 3. The Acid Content of Roasted Coffee.- 3.1. Identified acids.- 3.2. Quantitative data.- 3.3. Changes on roasting.- 3.4. Changes on storage.- 3.5. Relationships to perceived acidity.- 4. The Acid Content of Dried Coffee Extracts (Instant Coffees).- 5. Determination of Acids.- 5.1. pH and titratable acidity.- 5.2. Individual acids.- 6. The Origins of Acids Found in Coffee Infusions.- References.