Dairy Processing: Improving Quality

The dairy sector continues to be at the forefront of innovation in food processing. With its distinguished editor and international team of contributors, Dairy Processing: Improving Quality reviews key developments and their impact on product safety and quality The first two chapters provide a foundation for the rest of the book, summarising the latest research on the constituents of milk and reviewing how agricultural practice influences raw milk quality. The remainder of Part 1 focuses on key aspects of safety: good hygienic practice; improvements in pasteurisation and sterilisation; and the use of modelling to assess the effectiveness of pasteurisation. Part 2 reviews some of the major technological advances in the sector. It discusses on-line control of process efficiency and product quality, shelf-life, high pressure processing, drying and the production of powdered dairy products, and the use of dissolved carbon dioxide to extend the shelf-life of milk. Part 3 looks in detail at key advances in cheese manufacturing. This volume serves as a standard reference for the dairy industry in improving process efficiency and product quality.

Introduction

DAIRY PRODUCT SAFETY AND QUALITY

The Major Constituents of Milk
P.F. Fox, University College Cork, Ireland
Introduction
Lactose
Lipids
Proteins
Minor Proteins
Salts
References

Influences on Raw Milk Quality
M. Boland, Fonterra Research Centre, New Zealand
Introduction
Breed, Genetics and Milk Quality
Cow Diet and Milk Quality
Other Aspects of Animal Husbandry and Milk Quality
Future Trends
Sources of Further Information and Advice
Acknowledgements
References

Good Hygienic Practice in Milk Processing
M.C. te Giffel, NIZO Food Research, The Netherlands
Introduction
The Principal Hazards
Good Hygienic Practice
Future Trends
Sources of Further Information and Advice
Bibliography

Improvements in the Pasteurisation and Sterilisation of Milk
M. Lewis, The University of Reading, UK
Introduction
Kinetic Parameters in Heat Inactivation
Thermization and Tyndallisation
Pasteurisation
Factors Affecting the Effectiveness of Pasteurisation
Extended Shelf-Life Milks
Sterilisation
Ultra-high temperature (UHT) Sterilisation
Aseptic Packaging and Storage
References

Modelling the Effectiveness of Pasteurisation
R McKellar, Agriculture and Agri-Food Canada
Introduction: the Role of Predictive Modelling
The Development of Thermal Models
Key Steps in Model Development
Models for Key Enzymes and Pathogens
Modelling and Risk Assessment
Risk Assessment and Pasteurisation
Future Trends
Sources of Further Information and Advice
References

Flavour Generation in Dairy Products
A.E.M. Boelrijk, C. de Jong and G. Smit, NIZO Food Research, The Netherlands
Introduction
Raw and Heat-Treated Milk
Yoghurt and Buttermilk
Conclusion and Future Trends
Acknowledgements
References

Controlling the Texture of Dairy Products: The Case of Yoghurt
D Jaros and H Rohm, Dresden University of Technology, Germany
Introduction
The Manufacture of Yoghurt
Factors Affecting Yoghurt Texture
Measuring the Rheological and Textural Properties of Yoghurt
Future Trends
Sources of Further Information and Advice
References

Factors Affecting the Shelf-Life of Milk and Milk Products
D. Muir and J. Banks, Hannah Research Institute, UK
Introduction
Chemical Composition and Principal Reactions of
Milk
Bacteria in Milk and Related Enzyme Activity
Raw Milk Enzymes
Control of the Quality of Short Shelf-Life Products
Yoghurt and Fermented Milk
Factors Affecting the Stability of Long-Shelf-Life
Products
Control of the Stability of Long-Life Milk Products
Summary
Acknowledgement
Bibliography

Testing the Authenticity of Milk and Milk Products
F. Ulberth, University of Agricultural Sciences, Austria
Introduction
Detecting and Quantifying Foreign Fats
Detecting Milk of Different Species
Detection of Non-Milk Proteins, Watering of Milk and
Alteration of the Casein/Whey Protein Ratio Measuring Heat Load
Identifying Geographical Origin
Conclusions
References

Functional Dairy Products
M Saxelin, R Korpela and A Mayra-Makinen, Valio Ltd, Finland
Introduction
Composition of Milk
Fermented Milk Products
What Do We Mean by Functional Dairy Products? Examples of Functional Dairy Products:
Gastrointestinal Health and General Well-Being
Examples of Functional Dairy Products:
Cardiovascular Health
Examples of Functional Dairy Products:
Osteoporosis and Other Conditions
Future Trends
Sources of Further Information and Advice
References

Developing and Approving Health Claims for Functional Dairy Products
J. Snel and R. van der Meer, NIZO Food Research, The Netherlands
Introduction
The Body's Defence Mechanisms
In vitro Studies
Animal Studies
Human Studies
Making Health Claims
Future Trends
Sources of Further Information and Advice
References

NEW TECHNOLOGIES TO IMPROVE QUALITY

On-Line Measurement of Product Quality in Dairy Processing
G Ellen and A Tudos, NIZO Food Research, The Netherlands
Introduction
On-Line Measurement of Physical Parameters
Measuring Product Composition
On-Line Microbiological Testing
Monitoring Fouling and Cleaning-in-Place
Future Trends
Sources of Further Information and Advice
References

Rapid On-Line Instrumentation to Ensure the Safety of Milk
A Amine, Universite Hassan II-Mahammedia, Morocco
L Micheli, D Moscone and G Palleschi, University di Roma 'Tor Vergata', Italy
Introduction
Monitoring Contamination During Milking: Faecal Contamination and Mycotoxins
Measuring the Effectiveness of Heat Treatment
Future Trends
References

High-Pressure Processing to Improve Dairy Product Quality
W Messens, Agricultural Research Centre - Ghent, Belgium
J van Camp and K Dewettinck, Ghent University, Belgium
Introduction: High Pressure Principles and Technologies
The Effects of High Pressure on Nutritional
and Other Qualities in Milk
The Effects of High Pressure on Bacteria
and Enzymes
The Effects of High Pressure on Milk Proteins
Effects on Other Properties of Milk
The Effects on Cheese and Yoghurt-Making
Properties of Milk
High-Pressure Treatment of Cheese
Future Trends
Sources of Further Information and Advice
References

Optimising Product Quality and Process Control for Powdered Dairy Products
E. Verdurmen and P. de Jong, NIZO Food Research, The Netherlands
Introduction: Evapouration and Drying Processes
Quality Criteria for Dairy-Based Powders
Modelling Quality
Process and Product Control
Ensuring Process Safety
Sources of Further Information and Advice
References

Separation Technologies to Produce Dairy Ingredients
G. Bargeman, Akzo Nobel Chemicals bv, The Netherlands
Introduction
Separation Technologies
Isolation of Ingredients
Developments in Separation Technology
Sources of Further Information and Advice
References

The Use of Dissolved Carbon Dioxide to Extend the Shelf-Life of Dairy Products
C Loss and J Hotchkiss, Cornell University, USA
Introduction: Factors Limiting the Shelf-Life of Dairy
Products
The Effect of Carbon Dioxide on Bacterial Growth
Effects of Carbon Dioxide on Raw Milk Quality
Effects of Carbon Dioxide on Dairy Product Quality
Bacteriocidal and Sporicidal Effects of Dissolved
Carbon Dioxide during Thermal Processing
References

CHEESE MANUFACTURE

Acceleration of Cheese Ripening
V Upadhyay and P McSweeney, University College Cork, Ireland
Introduction
Accelerating Cheese Ripening: Elevated
Temperature
Addition of Exogenous Enzymes or Attenuated
Starters
Use of Adjunct Cultures
Genetic Modification of Starter Bacteria
High Pressure Technology
Enzyme Modified Cheeses as Flavourings
Future Trends
Acknowledgement
Sources of Further Information and Advice
References

Non-Starter Lactic Acid Bacteria (NSLAB) and Cheese Quality
T Beresford, Dairy Products Research Centre, Ireland
Introduction
Bacteria Comprising the NSLAB Complex
NSLAB in Different Cheese Varieties
The Source of NSLAB in Cheese
The Growth of NSLAB in Cheese
The Influence of NSLAB on Cheese Quality
Selection of NSLAB Adjuncts for Quality Improvement
of Cheese
Conclusions
References

The Production of Smear Cheeses
W. Bockelman, BafM, Germany
Introduction: Smear-Ripened Cheese Varieties
Production and Ripening
Developing Ripening Cultures
Conclusions and Future Trends
Sources of Further Information and Advice
References

Flavour formation in Cheese
W. Engels, J. van Hylckama Vlieg and G. Smit, NIZO Food Research, The Netherlands
Introduction
Amino Acid Conversion
Amino Acid Catabolism
Methionine Catabolism
Branched-Chain and Aromatic Amino Acid
Conversion
Conversion of Other Amino Acids
Natural Biodiversity and Tailor-Made Starter Cultures
Future Trends
References

APPENDIX

Improving the Nutritional Quality of Milk
D.I. Givens and K.J. Shingfield, The University of Reading, UK
Introduction
Factors Affecting Milk Protein Content
Factors Affecting Milk Fat Content
Future Trends
References