The 4th International Symposium on Spray Dried Dairy Products was held on April 15–17th, 2009 in Melbourne, Australia. Building on the success of the earlier symposia in this series in Rennes (2001), Cork (2004) and San Francisco (2007), this combined conference and exhibition brought together more than 200 research and industry leaders from 15 different countries. Oral presentations, posters and trade displays covered the key themes of:

• advances in dairy spray-drying systems;

• modelling and control of spray-drying processes;

• alternative technologies for the manufacture of dried dairy ingredients;

• analysis and characterisation of dairy powder properties;

• functionality and applications of spray-dried and dairy-based ingredients.

The selection of Symposium papers published in this special issue of Dairy Science & Technology illustrates both the high quality of contributions and the dual focus on scientific and industrial challenges, which has become a particular feature of this symposium series. On the scientific front, it is clear that the application of new analytical techniques and experimental approaches is steadily advancing our understanding of how the functionality of dairy ingredients is linked to chemical composition, physical properties and microstructure. In dairy manufacturing, continuing advances in process modelling and in the development of new processing technologies are providing valuable new industrial tools for control and optimisation of energy/cost efficiency and product quality/functionality.

In the prevailing economic climate, the Symposium was very fortunate to receive generous levels of sponsorship from a variety of sources. I am particularly grateful to our major sponsors – Dairy Innovation Australia, Tetra Pak, GEA Niro, The Victorian Government and Warrnambool Cheese & Butter Factory. Thanks also to Dairy Science & Technology, whose kind sponsorship of this Special Edition has allowed a selection of the best papers from this Symposium to be shared with a much wider audience. I also like to thank our International Organising Committee, particularly Drs. Mike Weeks and Pierre Schuck, without whom we would not have been able to assemble such an exciting and diverse programme and present this impressive selection of papers.

I look forward to meeting you in 2012 in St. Malo, France, for the 5th Symposium in this series, to be hosted by INRA, under the leadership of Dr. Pierre Schuck.

© INRA, EDP Sciences, 2010