High Temperature Processing of Milk and Milk Products

Hilton C. Deeth, Michael J. Lewis

• Publisher: Wiley-Blackwell
• Year: 2017
• Print ISBN: 9781118460504
• eBook ISBN: 9781118460498
• Edition: 1
• Topic: Technology & Engineering
• Subtopic: Food Science
• Index: Technology & Engineering

This book covers many aspects of thermal processing of milk and milk products with particular focus on UHT processing. It commences with an overview of the major thermal processing technologies: thermisation, pasteurisation, extended-shelf-life (ESL), UHT and in-container sterilisation.  It discusses the principles of the technologies, the processing and packaging equipment used, processing issues such as temperature-time profiles, heat stability, fouling and cleaning, and the quality and safety aspects of the products produced. It provides a balance of the engineering aspects of the processes and the chemical, microbiological and sensory aspects of the products.  The changes that occur in products during processing and storage, and the related defects which can arise, are central to the book.  The discussions of these changes will be an aid to industry personnel in identifying the causes of quality defects in these products and devising measures which can be taken to eliminate or minimise the defects.

1
History and Scope of the Book

1.1 Setting the Scene

Bovine milk is the main source of milk in the world today. Table 1.1 illustrates some production data for the leading bovine milk producing countries in the world. The first column shows total milk production, whereas the second shows milk production expressed as per head of population. Thus countries like New Zealand and Ireland (see footnote) produce large quantities per capita, whereas countries such as China, although positioned in the top five milk producers in the world, are most probably not producing sufficient milk for their increasing populations who are developing a taste for milk and milk products. USA and Brazil are also large producers of bovine milk. Much of the milk in Brazil is consumed as liquid milk with a fair proportion being UHT processed.

Table 1.1 Leading producers of bovine milk in 2012, with populations and production per head of population.

from: http://dairy.ahdb.org.uk/market‐information/supply‐production/milk‐production/world‐milk‐production/#.VzxQVHn2aUk and world population figures

	Milk production, 2012 (billion L)	Population (billion)	Per capita consumption (L/person)
United States of America	90.9	0.318	286
India	54.0	1.244	43.4
China	37.8	1.364	27.7
Brazil	32.3	0.204	158
Russian Federation	31.6	0.146	216
Germany	30.5	0.081	377
France	24.0	0.066	364
New Zealand	20.0	0.0046	4350
Turkey	16.0	0.078	205
United Kingdom	13.9	0.065	214
World	620.3	7.25	85.6

It is very exciting time to be writing a book on high‐temperature processing, particularly ultra‐high temperature (UHT) processing. UHT is a continuous process and as such is applicable to any product that can be pumped through a heat exchanger and then aseptically packaged, although the vast majority of products are either milk or milk‐based. UHT milk and milk products are now global commodities and are being transported large distances to all parts of the world. In a number of traditional milk‐drinking countries, for example, UK, Greece and Australia, pasteurised milk is still the milk of preference and the cooked flavour that is associated with UHT and sterilised milk is given as a major reason for maintaining this status quo (Perkins & Deeth, 2011). In contrast, in some other countries much more UHT milk is consumed than pasteurised milk. For example, in France, Belgium and Portugal, more than 90% of all liquid milk purchased is UHT‐treated, whereas in the UK, Norway, Sweden, Australia and New Zealand, it is less than 10%. Similar variations are also found in other parts of the world, with less than 5% of UHT milk being consumed in India and USA but over 60% in Vietnam and China. In other words, availability and also preferences for pasteurised or sterilised milk vary from country to country. Some examples for Europe and other parts of the world are given in Table 1.2.

Table 1.2 Percentage of drinking milk which is UHT processed in various European countries and worldwide.

Information from Wikipedia and Datamonitor (China has the largest forecast growth increase in UHT milk consumption over the period 2012 to 2020. India also has a high projected growth rate but is starting from a much lower base level).

Europe
Greece	0.9
Norway	5.3
UK	8.4
Austria	20.3
Germany	66.1
France	95.5
Spain	95.7
Belgium	96.7
Worldwide
US	2
India	3
Australia	11
Japan	11
Malaysia	28
China	32
Thailand	46
Vietnam	62

Recently, there has been a substantial increase in UHT capacity in all parts of the world. In part, this is to supply the increased demand for UHT milk from China. It is also predicted that there will be an increased demand from Africa and other parts of South East Asia. Since UHT milk does not require refrigeration and has a long shelf‐life, it provides a very convenient way of providing good quality milk to large populations in remote areas, without the need for the expensive cold chain infrastructure. UHT milk is now transported to China and other parts of South East Asia from countries such as Australia, New Zealand and even longer distances from USA and several countries in Europe. Both large multinational conglomerates and much smaller companies are engaged in these activ...

Table of contents

• Cover
• Title Page
• Table of Contents
• About the Authors
• Preface
• List of Abbreviations
• 1 History and Scope of the Book
• 2 Heat Treatments of Milk – Thermisation and Pasteurisation
• 3 Heat Treatments of Milk – ESL, UHT and in‐Container Sterilisation
• 4 Microbiological Aspects
• 5 UHT Processing and Equipment
• 6 Changes During Heat Treatment of Milk
• 7 Changes During Storage of UHT Milk
• 8 Quality Control and Assurance
• 9 Other Shelf‐Stable Products
• 10 Non‐Thermal Technologies
• 11 Analytical Methods
• 12 Concluding Comments
• Index
• End User License Agreement