Microbial Toxins in Dairy Products

Adnan Y. Tamime is a Consultant in Dairy Science and Technology, Ayr, UK. He is the Series Editor of the SDT's Technical Book Series.

• List of Contributors xiPreface to the Technical Series xvPreface xvi1 Microbial Toxins – An Overview 1R. Early and A.Y. Tamime1.1 Introduction 11.2 Microbial toxins: modes of action 21.3 Bacterial toxins 41.3.1 Staphylococcal enterotoxins (SEs) 41.3.2 Bacillus cereus group enterotoxins 61.3.3 Clostridium botulinum nerotoxin 61.4 Mycotoxins 71.4.1 Background 71.4.2 General aspects of mycotoxins 71.4.3 Postscript on mycotoxins 131.5 Biogenic amines (BAs) 141.6 Conclusions 14References 162 Incidences of Mould and Bacterial Toxins in Dairy Products 19M.L.Y. Wan, N.P. Shah and H.I. El-Nezami2.1 Background 192.2 Bacterial toxins 192.2.1 Emetic toxin produced by Bacillus cereus 202.2.2 Enterotoxins produced by Staphylococcus aureus 242.2.3 Botulinum neurotoxins produced by Clostridium botulinum 262.3 Mould toxins (mycotoxins) 332.3.1 Aflatoxins B1 and M1 342.3.2 Sterigmatocystin 422.3.3 Ochratoxin A 432.4 Other mycotoxins 472.5 Conclusion 49References 503 Bacterial Toxins – Structure, Properties and Mode of Action 71J.W. Austin3.1 Background 713.2 Bacillus cereus toxins 723.2.1 Bacillus cereus emetic toxin 733.2.2 Bacillus cereus enterotoxins 743.2.3 Bacillus cereus haemolysin BL (Hbl) 763.2.4 Bacillus cereus non-haemolytic enterotoxin (Nhe) 763.2.5 Cytotoxin K (Cyt K) 773.3 Botulinum neurotoxin 773.3.1 Outbreaks of botulism caused by dairy products 783.3.2 Structure of botulinum neurotoxin 793.3.3 Mode of action of BoNTs 803.4 Staphylococcus aureus enterotoxin 803.5 Conclusions 83References 834 Biogenic Amines in Dairy Products 94V. Ladero, D.M. Linares, M. Pérez, B. del Rio, M. Fernández and M.A. Alvarez4.1 Introduction 944.2 Biochemistry: biosynthesis pathways, enzymes and transporters 984.2.1 Tyramine 984.2.2 Histamine 994.2.3 Putrescine 1004.2.4 Cadaverine, β-phenylethylamine, tryptamine 1014.3 Biogenic amine-producing micro-organisms 1014.3.1 Genes involved in the biosynthesis of biogenic amines 1034.3.2 Is the production of BAs a strain- or species-dependent characteristic? 1054.3.3 Physiological functions of BAs biosynthesis 1064.4 Toxicological effects 1074.4.1 Tyramine 1084.4.2 Histamine 1094.4.3 Putrescine and polyamines 1104.4.4 Cadaverine, tryptamine and β-phenylethylamine 1114.4.5 Recommended limits of BAs 1114.5 Factors affecting BAs accumulation in dairy products 1134.5.1 Presence of BAs-producing bacteria 1134.5.2 Physiochemical factors 1144.5.3 Technological factors 1174.6 Other preventive methods 1194.7 Conclusions 119Acknowledgements 120References 1205 Contamination of Raw Milk: Sources and Routes Up to the Farm Gate 132R. Early5.1 Introduction 1325.2 The concept of contamination 1325.2.1 What does contamination mean to the concept of food? 1345.2.2 Contamination and cow health 1355.3 Sources of contamination 1365.3.1 Biological contamination 1365.3.2 Chemical contamination 1425.3.3 Mycotoxins 1475.3.4 Physical contamination 1485.4 Conclusion 150References 1506 Milk Product Contamination After the Farm Gate 154R. Early6.1 Introduction 1546.2 The significance of microbial contamination 1546.2.1 Product spoilage 1546.2.2 Food-borne illness 1556.2.3 Microbial toxins 1556.3 Factories, processes and people 1576.4 Raw milk handling 1586.5 Milk-processing and dairy products manufacture 1606.5.1 Liquid milk and cream processing 1616.5.2 Packing, storage, distribution and the retail environment 1626.6 Buttermaking 1646.7 Cheesemaking 1656.8 Yoghurt 1686.9 Milk powders 1706.10 Evaporated milk and sweetened condensed milk 1726.10.1 Evaporated milk 1726.10.2 Sweetened condensed milk 1756.11 Ice-cream 1756.12 Hygiene, food safety management and cleaning-in-place (CIP) 1776.13 Packaging, storage, distribution and the retail environment 1786.14 Conclusions 180References 1807 Techniques for Detection, Quantification and Control of Bacterial Toxins 183L. Ramchandran, A. Warnakulasuriya, O. Donkor and T. Vasiljevic7.1 Introduction 1837.2 Bacterial toxins 1847.3 Control of toxins 1867.4 Methods for identification and detection of microbial toxins 1877.4.1 Traditional biological assays 1897.4.2 Antibody and immunoassay 1917.5 Conclusion 196References 1968 Techniques for Detection, Quantification and Control of Mycotoxins in Dairy Products 201O. Donkor, L. Ramchandran and T. Vasiljevic8.1 Introduction 2018.2 Methods for detection and quantification of mycotoxins 2038.2.1 Sample pre-treatment method 2038.2.2 Liquid-liquid extraction 2048.2.3 Supercritical fluid extraction 2048.2.4 Solid phase extraction 2048.3 Separation methods 2068.3.1 Thin layer chromatography 2068.3.2 High pressure liquid chromatography (HPLC) 2088.3.3 Gas chromatography (GC) 2108.3.4 Capillary electrophoresis (CE) 2108.3.5 Biosensors 2108.3.6 Enzyme-linked immmunosorbent assay (ELISA) method 2128.3.7 Electrochemical immunoassay 2148.3.8 Polymerase chain reaction (PCR)-based detection and quantification 2158.4 Mathematical model (exposure assessment of mycotoxins in dairy milk) 2168.5 Control of mycotoxin 2178.5.1 Physical methods 2188.5.2 Chemical methods 2188.5.3 Biological methods 2198.5.4 Activated carbon (AC) 2198.6 Conclusion 220References 2209 Approaches to Assess the Risks/Modelling of Microbial Growth and Toxin Production 229N. Murru, R. Mercogliano, M.-L. Cortesi, F. Leroy, R. Condoleo and M.F. Peruzy9.1 Background on risk analysis 2299.2 Focus on cheese risk assessment 2319.2.1 Source of milk 2319.2.2 Raw and/or heat-treated milk cheeses 2319.2.3 Level of moisture in cheese 2329.2.4 Methods of manufacture 2329.2.5 Fat content 2329.2.6 Maturation indices 2329.2.7 Washed or mould cheeses 2339.3 Staphylococcus aureus 2339.3.1 Background 2339.3.2 Staphylococcus aureus and production of staphylococcal eneterotoxins 2349.3.3 Cheese production and hazard characterisation of Staphylococcus aureus 2379.3.4 Cheesemaking conditions and exposure assessment of Staphylococcus aureus 2389.3.5 Predictive modelling and risk assessment of Staphylococcus aureus and enterotoxin production in cheese 2429.4 Escherichia coli 2439.4.1 Hazard identification 2439.4.2 Growth and inactivation 2449.4.3 Hazard characterisation 2449.4.4 Exposure assessment 2469.4.5 Risk characterisation 2489.5 Listeria monocytogenes 2519.5.1 Hazard characterisation 2519.5.2 Exposure assessment 2539.5.3 Hazard characterisation 2569.5.4 Risk characterisation 2589.6 Cheese - chemical risk assessment 2599.6.1 Background 2599.6.2 Biogenic amines in cheese 2609.6.3 Occurrence of biogenic amines in cheese: hazard and exposure assessment 2609.6.4 Method for controlling biogenic amines in food 2639.7 Modelling of growth and inactivation: kinetic approaches 2649.7.1 Model categories: an overview 2649.7.2 Growth - no growth interface: a probabilistic approach 2679.7.3 Modelling of toxin production 2689.8 Conclusions 268References 26910 Regulatory Measures for Microbial Toxins 287M. Hickey10.1 Introduction and background 28710.2 The evolution and economic significance of heat-treated milk and milk products 28810.2.1 Fluid milk 28910.2.2 Evaporated and sweetened condensed milks 28910.2.3 Milk and dairy powders 29010.2.4 Cheeses (natural and processed) and fermented milks 29110.3 Bacterial toxins 29210.3.1 Staphylococcal enterotoxins 29210.3.2 Bacillus cereus toxins 29310.3.3 Clostridium botulinum toxins 29410.4 Regulatory provisions on bacterial toxins in milk and milk products 29710.4.1 European regulations on food hygiene and food safety 29710.4.2 US milk hygiene and food safety standards 30310.4.3 International perspective on food hygiene and safety – Codex Alimentarius 30710.5 Mycotoxins 31010.5.1 Aflatoxins 31110.5.2 Other mycotoxins 31110.5.3 Aflatoxins M1 and B1 and their regulatory provisions 31210.5.4 EU legislations on aflatoxins in milk, milk products and animal feed 31310.5.5 Regulations of aflatoxins of importance in milk and milk products in the USA 31410.5.6 Regulations of aflatoxins of importance in milk and milk products in Canada 31410.5.7 Regulation of aflatoxins in Australia and New Zealand 31510.5.8 MERCOSUR standard on aflatoxins 31510.6 Conclusions 316References 316Index 323