《食品化学》课程教学资源（书籍文献）Food Chemistry，H.-D. Belitz · W. Grosch · P. Schieberle，4th revised and extended ed..pdf_P36-P40

Contents xxxix 20.2.6.7 Nitrogen Compounds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 921 20.2.6.8 Minerals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 921 20.2.6.9 Aroma Substances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 921 20.2.7 Spoilage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 924 20.2.8 Liqueur Wines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 926 20.2.9 Sparkling Wine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 926 20.2.9.1 Bottle Fermentation (“Méthode Champenoise”) . . . . . . . . . . . . . . 927 20.2.9.2 Tank Fermentation Process (“Produit en Cuve Close”) . . . . . . . . 927 20.2.9.3 Carbonation Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 928 20.2.9.4 Various Types of Sparkling Wines . . . . . . . . . . . . . . . . . . . . . . . . . 928 20.2.10 Wine-Like Beverages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 928 20.2.10.1 Fruit Wines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 928 20.2.10.2 Malt Wine; Mead . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 929 20.2.10.3 Other Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 929 20.2.11 Wine-Containing Beverages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 929 20.2.11.1 Vermouth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 929 20.2.11.2 Aromatic Wines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 929 20.3 Spirits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 929 20.3.1 Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 929 20.3.2 Liquor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 929 20.3.2.1 Production . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 929 20.3.2.2 Alcohol Production . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 930 20.3.2.3 Liquor from Wine, Fruit, Cereals and Sugar Cane . . . . . . . . . . . . 931 20.3.2.3.1 Wine Liquor (Brandy) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 931 20.3.2.3.2 Fruit Liquor (Fruit Brandy) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 931 20.3.2.3.3 Gentian Liquor (“Enzian”) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 932 20.3.2.3.4 Juniper Liquor (Brandy) and Gin . . . . . . . . . . . . . . . . . . . . . . . . . . 932 20.3.2.3.5 Rum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 932 20.3.2.3.6 Arrack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 933 20.3.2.3.7 Liquors from Cereals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 933 20.3.2.4 Miscellaneous Alcoholic Beverages . . . . . . . . . . . . . . . . . . . . . . . . 935 20.3.3 Liqueurs (Cordials) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 935 20.3.3.1 Fruit Sap Liqueurs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 935 20.3.3.2 Fruit Aroma Liqueurs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 935 20.3.3.3 Other Liqueurs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 935 20.3.4 Punch Extracts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 936 20.3.5 Mixed Drinks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 936 20.4 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 936 21 Coffee, Tea, Cocoa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 938 21.1 Coffee and Coffee Substitutes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 938 21.1.1 Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 938 21.1.2 Green Coffee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 939 21.1.2.1 Harvesting and Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 939 21.1.2.2 Green Coffee Varieties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 939 21.1.2.3 Composition of Green Coffee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 940 21.1.3 Roasted Coffee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 940 21.1.3.1 Roasting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 940 21.1.3.2 Storing and Packaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 941 21.1.3.3 Composition of Roasted Coffee . . . . . . . . . . . . . . . . . . . . . . . . . . . . 942 21.1.3.3.1 Proteins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 942

xl Contents 21.1.3.3.2 Carbohydrates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 942 21.1.3.3.3 Lipids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 942 21.1.3.3.4 Acids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 943 21.1.3.3.5 Caffeine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 943 21.1.3.3.6 Trigonelline, Nicotinic Acid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 944 21.1.3.3.7 Aroma Substances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 944 21.1.3.3.8 Minerals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 946 21.1.3.3.9 Other Constituents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 946 21.1.3.4 Coffee Beverages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 946 21.1.4 Coffee Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 948 21.1.4.1 Instant Coffee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 948 21.1.4.2 Decaffeinated Coffee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 949 21.1.4.3 Treated Coffee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 949 21.1.5 Coffee Substitutes and Adjuncts . . . . . . . . . . . . . . . . . . . . . . . . . . . 949 21.1.5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 949 21.1.5.2 Processing of Raw Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 949 21.1.5.3 Individual Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 950 21.1.5.3.1 Barley Coffee. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 950 21.1.5.3.2 Malt Coffee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 950 21.1.5.3.3 Chicory Coffee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 950 21.1.5.3.4 Fig Coffee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 950 21.1.5.3.5 Acorn Coffee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 950 21.1.5.3.6 Other Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 950 21.2 Tea and Tea-Like Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 951 21.2.1 Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 951 21.2.2 Black Tea . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 951 21.2.3 Green Tea . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 952 21.2.4 Grades of Tea. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 952 21.2.5 Composition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 952 21.2.5.1 Phenolic Compounds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 953 21.2.5.2 Enzymes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 953 21.2.5.3 Amino Acids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 954 21.2.5.4 Caffeine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 954 21.2.5.5 Carbohydrates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 954 21.2.5.6 Lipids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 955 21.2.5.7 Pigments (Chlorophyll and Carotenoids) . . . . . . . . . . . . . . . . . . . . 955 21.2.5.8 Aroma Substances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 955 21.2.5.9 Minerals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 956 21.2.6 Reactions Involved in the Processing of Tea . . . . . . . . . . . . . . . . . 956 21.2.7 Packaging, Storage, Brewing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 958 21.2.8 Maté (Paraguayan Tea) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 958 21.2.9 Products from Cola Nut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 958 21.3 Cocoa and Chocolate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 959 21.3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 959 21.3.2 Cacao . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 959 21.3.2.1 General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 959 21.3.2.2 Harvesting and Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 960 21.3.2.3 Composition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 961 21.3.2.3.1 Proteins and Amino Acids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 961 21.3.2.3.2 Theobromine and Caffeine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 962 21.3.2.3.3 Lipids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 962

Contents xli 21.3.2.3.4 Carbohydrates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 962 21.3.2.3.5 Phenolic Compounds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 962 21.3.2.3.6 Organic Acids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 963 21.3.2.3.7 Volatile Compounds and Flavor Substances . . . . . . . . . . . . . . . . . . 964 21.3.2.4 Reactions During Fermentation and Drying. . . . . . . . . . . . . . . . . . 964 21.3.2.5 Production of Cocoa Liquor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 965 21.3.2.6 Production of Cocoa Liquor with Improved Dispersability . . . . . 965 21.3.2.7 Production of Cocoa Powder by Cocoa Mass Pressing . . . . . . . . . 966 21.3.3 Chocolate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 966 21.3.3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 966 21.3.3.2 Chocolate Production . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 966 21.3.3.2.1 Mixing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 966 21.3.3.2.2 Refining . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 966 21.3.3.2.3 Conching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 966 21.3.3.2.4 Tempering and Molding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 967 21.3.3.3 Kinds of Chocolate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 967 21.3.4 Storage of Cocoa Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 969 21.4 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 969 22 Spices, Salt and Vinegar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 971 22.1 Spices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 971 22.1.1 Composition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 971 22.1.1.1 Components of Essential Oils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 971 22.1.1.2 Aroma Substances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 974 22.1.1.2.1 Pepper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 975 22.1.1.2.2 Vanilla . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 976 22.1.1.2.3 Dill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 976 22.1.1.2.4 Fenugreek . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 976 22.1.1.2.5 Saffron . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 977 22.1.1.2.6 Mustard, Horseradish . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 977 22.1.1.2.7 Ginger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 977 22.1.1.2.8 Basil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 977 22.1.1.2.9 Parsley . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 978 22.1.1.3 Substances with Pungent Taste . . . . . . . . . . . . . . . . . . . . . . . . . . . . 979 22.1.1.4 Pigments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 981 22.1.1.5 Antioxidants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 981 22.1.2 Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 981 22.1.2.1 Spice Powders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 981 22.1.2.2 Spice Extracts or Concentrates (Oleoresins) . . . . . . . . . . . . . . . . . 982 22.1.2.3 Blended Spices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 982 22.1.2.4 Spice Preparations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 982 22.1.2.4.1 Curry Powder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 982 22.1.2.4.2 Mustard Paste . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 982 22.1.2.4.3 Sambal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 982 22.2 Salt (Cooking Salt) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 982 22.2.1 Composition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 982 22.2.2 Occurrence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 983 22.2.3 Production . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 983 22.2.4 Special Salt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 983 22.2.5 Salt Substitutes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 983 22.3 Vinegar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 983

IntroductionFoods are materials which, in their naturally occurring,processed or cooked forms,are consumed by humans as nourishment and forenjoyment.The terms"nourishment"and“enjoyment"introduce two important properties offoods:the nutritional value and the hedonic value.The former is relatively easy toquantify since all the important nutrients are known and their effects are defined.Furthermore, there are onlya limited number of nutrients.Defining the hedonicvalueof afood is more difficult because such adefinitionmusttake into accountall those properties of afood, such as visual appeal, smell, taste and texture,whichinteract with the senses. These properties can be influenced by a large number ofcompounds which in part have not even been identified. Besides their nutritionaland hedonic values, foods are increasingly being judged according to propertieswhich determine their handling. Thus, the term “convenience foods".An obviousadditional requirement of a food is that it be free from toxic materials.Food chemistry is involved not only in elucidating the composition of the raw ma-terials and end-products, but also with the changes which occur in food during itsproduction, processing, storage and cooking.The highly complex nature of foodresults in a multitude of desired and undesired reactions which are controlled bya variety of parameters.To gain a meaningful insight into these reactions,it is nec-essaryto break upthefood into model systems.Thus,starting from compositionalanalyses (detection,isolation and structural characterization of food constituents)the reactions of a single constituent or of a simple mixture can befollowed.Sub-sequently,an investigationof afood in which an individual reaction dominatescanbe made.Inherently, such a study starts with a given compound and is thus notrestricted toany onefood orgroup of foods.Suchgeneral studiesofreactions in-volving food constituents are supplemented by special investigations which focuson chemical processes in individual foods. Research of this kind is from the verybeginning closely associated with economicand technological aspects and con-tributes, by understanding the basics of the chemical processes occurring in foods,bothtoresolvingspecifictechnicalproblemsandtoprocessoptimization.A comprehensiveevaluation offoods requires that analytical techniqueskeeppacewith the available technology.As a result a major objective in food chemistry isconcerned with the application and continual development of analytical methods.This aspect is particularly important when following possible contamination offoods with substances whichmayinvolve a healthrisk.Thus, there are close linkswithenvironmentalproblems.Food chemistry research is aimed at establishing objective standards by which thecriteria mentioned above-nutritional value,hedonic value,absenceof toxic com-pounds and convenience -can be evaluated. These are a prerequisite for the indus-trial production of high qualityfood inbulk amounts

Introduction Foods are materials which, in their naturally occurring, processed or cooked forms, are consumed by humans as nourishment and for enjoyment. The terms “nourishment” and “enjoyment” introduce two important properties of foods: the nutritional value and the hedonic value. The former is relatively easy to quantify since all the important nutrients are known and their effects are defined. Furthermore, there are only a limited number of nutrients. Defining the hedonic value of a food is more difficult because such a definition must take into account all those properties of a food, such as visual appeal, smell, taste and texture, which interact with the senses. These properties can be influenced by a large number of compounds which in part have not even been identified. Besides their nutritional and hedonic values, foods are increasingly being judged according to properties which determine their handling. Thus, the term “convenience foods”. An obvious additional requirement of a food is that it be free from toxic materials. Food chemistry is involved not only in elucidating the composition of the raw materials and end-products, but also with the changes which occur in food during its production, processing, storage and cooking. The highly complex nature of food results in a multitude of desired and undesired reactions which are controlled by a variety of parameters. To gain a meaningful insight into these reactions, it is necessary to break up the food into model systems. Thus, starting from compositional analyses (detection, isolation and structural characterization of food constituents), the reactions of a single constituent or of a simple mixture can be followed. Subsequently, an investigation of a food in which an individual reaction dominates can be made. Inherently, such a study starts with a given compound and is thus not restricted to any one food or group of foods. Such general studies of reactions involving food constituents are supplemented by special investigations which focus on chemical processes in individual foods. Research of this kind is from the very beginning closely associated with economic and technological aspects and contributes, by understanding the basics of the chemical processes occurring in foods, both to resolving specific technical problems and to process optimization. A comprehensive evaluation of foods requires that analytical techniques keep pace with the available technology. As a result a major objective in food chemistry is concerned with the application and continual development of analytical methods. This aspect is particularly important when following possible contamination of foods with substances which may involve a health risk. Thus, there are close links with environmental problems. Food chemistry research is aimed at establishing objective standards by which the criteria mentioned above – nutritional value, hedonic value, absence of toxic compounds and convenience – can be evaluated. These are a prerequisite for the industrial production of high quality food in bulk amounts