Food Preservatives

1 Major, new, and emerging food-poisoning and food-spoilage microorganisms.- 1.1 Introduction.- 1.2 Food-poisoning microorganisms.- 1.3 Food-spoilage microorganisms.- 1.4 Conclusions.- References.- 2 Major preservation technologies.- 2.1 Introduction.- 2.2 Basis of food preservation.- 2.3 Major food preservation techniques.- 2.4 Conclusions.- References.- 3 Acidulants and low pH.- 3.1 Introduction.- 3.2 Direct action of pH and acids on microorganisms.- 3.3 Acid as an indirect stress: consequences of lowering cytoplasmic pH.- 3.4 Acids in foods: the antimicrobial effectiveness of different acids.- 3.5 The relationship of pH to growth and survival.- 3.6 Acid-resistant food pathogens and spoilage microorganisms.- 3.7 Adaptation to low pH.- 3.8 Conclusions.- References.- 4 Organic acids and esters.- 4.1 Summary.- 4.2 Introduction.- 4.3 The use of organic acids and esters in foods.- 4.4 Chemical properties of organic acids and esters.- 4.5 General mechanisms of antimicrobial action.- 4.6 Organic acids as antimicrobial agents.- 4.7 Esters as antimicrobial agents.- 4.8 Adaptation and resistance by microorganisms.- 4.9 Conclusions.- References.- 5 Sulfite.- 5.1 Introduction.- 5.2 Uses in foods.- 5.3 Mode of action.- 5.4 Postscript.- References.- 6 Nitrite.- 6.1 Introduction.- 6.2 Sources of nitrates and nitrites.- 6.3 Health concerns with sodium nitrite in cured meats.- 6.4 Nitrate and nitrite metabolism.- 6.5 N-nitroso compound formation in cured meats.- 6.6 N-nitroso compounds and human health.- 6.7 Effect of additives and ingredients on nitrosamine formation.- 6.8 Regulation of nitrite in cured meats.- 6.9 Functions of nitrite in meat curing.- 6.10 Conclusions.- References.- 7 Solutes and low water activity.- 7.1 Introduction.- 7.2 Influence of water activity on microorganisms.- 7.3 Foods.- 7.4 Microbial response to low water activity: basic mechanisms.- 7.5 Combined factors.- References.- 8 Bacteriocins — Nisin.- 8.1 Introduction.- 8.2 Definition of nisin activity and nisin potency.- 8.3 Methods of assay.- 8.4 Stability and solubility.- 8.5 Antimicrobial spectrum.- 8.6 Mode of action.- 8.7 Factors affecting nisin action.- 8.8 Toxicological studies.- 8.9 Practical applications of nisin and food preservation.- 8.10 Genetics and maturation pathway of nisin.- 8.11 Protein engineering of nisin.- References.- 9 Natamycin.- 9.1 Introduction.- 9.2 Physical and chemical properties.- 9.3 Mechanism of action.- 9.4 Sensitivity of fungi to natamycin.- 9.5 Inhibition of mycotoxin formation by natamycin.- 9.6 Applications of natamycin.- 9.7 Regulatory food status of natamycin.- References.- 10 Ethanol as a food preservative.- 10.1 Introduction.- 10.2 Use of ethanol in food preservation.- 10.3 Anti-staling effects.- 10.4 Indirect use of ethanol in food technology.- 10.5 Synergy of ethanol and other antimicrobials.- 10.6 Antimicrobial mode of action.- 10.7 Legal considerations.- References.- 11 Modified atmospheres and vacuum packaging.- 11.1 Introduction.- 11.2 Gases used and their modes of action.- 11.3 Factors other than packaging affecting spoilage development.- 11.4 Non-microbial product deterioration.- 11.5 Packaging materials.- 11.6 Packaging machines.- 11.7 Microbial ecology.- 11.8 Microbial safety.- 11.9 Developments in MAP.- 11.10 Conclusions.- Acknowledgments.- References.- 12 Surface preservation for fruits and vegetables.- 12.1 Introduction.- 12.2 Factors affecting the quality of fruits and vegetables.- 12.3 Surface washing of fruits and vegetables.- 12.4 Surface preservatives for fruits and vegetables.- 12.5 Summary.- References.- 13Naturally occurring antimicrobial systems.- 13.1 Introduction.- 13.2 A systems approach to food preservation.- 13.3 Agents that damage microbial cell walls: lysozyme and other hydrolytic enzymes.- 13.4 Agents that perturb the physiology of microbial membranes: lactoperoxidase.- 13.5 Agents that impair microbial metabolism: iron chelators and avidin.- 13.6 Agents having a generalized and ill-defined role: plant extracts and phenolics.- 13.7 Future prospects.- Acknowledgments.- References.- 14 Starter and protective cultures.- 14.1 Introduction.- 14.2 Bacterial starters and protective cultures.- 14.3 Fungi in food processing.- 14.4 Future prospects and genetic optimization.- References.- 15 Legislative aspects.- 15.1 Introduction.- 15.2 Role of preservatives.- 15.3 Legislation of preservatives.- 15.4 Future trends in preservatives legislation.- References.- 16 Food preservatives — future prospects.- 16.1 Introduction.- 16.2 Stress response and virulence.- 16.3 Risk analysis.- 16.4 Some specific preservative issues.- References.