Modern Drying Technology E-Book

• Herausgeber: Wiley-VCH
• Kategorie: Fachliteratur
• Sprache: Englisch

Seitenzahl: 777

Veröffentlichungsjahr: 2011

Beschreibung

This five-volume series provides a comprehensive overview of all important aspects of modern drying technology, concentrating on the transfer of cutting-edge research results to industrial use. Volume 3 discusses how desired properties of foods, biomaterials, active pharmaceutical ingredients, and fragile aerogels can be preserved during drying, and how spray drying and spray fluidized bed processes can be used for particle formation and formulation. Methods for monitoring product quality, such as process analytical technology, and modeling tools, such as Monte Carlo simulations, discrete particle modeling and neural networks, are presented with real examples from industry and academia.

Leseprobe

Contents

Cover

Modern Drying Technology

Title Page

Copyright

Series Preface

Preface of Volume

List of Contributors

Recommended Notation

EFCE Working Party on Drying: Address List

Chapter 1: Quality Changes in Food Materials as Influenced by Drying Processes

1.1 Introduction

1.2 Biochemical Reactions Induced by Drying

1.3 Physical Transformations During Drying

1.4 Mechanical Transformations Induced by Drying

1.5 Storage and Rehydration of Food Products

1.6 Conclusion

References

Chapter 2: Impact of Drying on the Mechanical Properties and Crack Formation in Rice

2.1 Introduction

2.2 Impact of Drying Conditions on Head Rice Yield for Paddy and Parboiled Rice

2.3 Characterization of Fissures Formation by Image Analysis Techniques

2.4 Characterization of the Mechanical Properties of the Rice Material

2.5 Modeling the Impact of Drying on the Final Quality of Rice Grains

2.6 Conclusion

References

Chapter 3: Characterization and Control of Physical Quality Factors During Freeze-Drying of Pharmaceuticals in Vials

3.1 Introduction

3.2 Characterization Methods of the Key Quality Factors During Freeze-Drying of Pharmaceuticals in Vials

3.3 Influence of Freezing and Freeze-Drying Parameters on Physical Quality Factors

3.4 Product Quality and Stability During Drying and Storage

3.5 Conclusions

References

Chapter 4: In-Line Product Quality Control of Pharmaceuticals In Freeze-Drying Processes

4.1 Introduction

4.2 Control of the Freezing Step

4.3 Monitoring of the Primary Drying

4.4 Control of the Primary Drying

4.5 Monitoring and Control of Secondary Drying

4.6 Quality by Design

4.7 Continuous Freeze-Drying

4.8 Conclusion

Acknowledgements

References

Chapter 5: Understanding and Preventing Structural Changes During Drying of Gels

5.1 Introduction

5.2 Gels and Their Applications – Quality Aspects

5.3 Structural Characterization of Gels – Quality Assessment

5.4 Drying Methods for Gels – Quality Loss

5.5 Advanced Drying Techniques – Preserving Quality

5.6 Advanced Modeling of Convective Drying – Understanding Quality

5.7 Summary

References

Chapter 6: Morphology and Properties of Spray-Dried Particles

6.1 Introduction

6.2 Morphology of Spray-Dried Particles

6.3 Retention of Flavor in Spray-Dried Food Products

6.4 Encapsulation and Microencapsulation of Enzymes and Oil by Spray Drying

6.5 General Quality Aspects

6.6 Concluding Remarks

References

Chapter 7: Particle Formulation in Spray Fluidized Beds

7.1 Introduction

7.2 General Principles of Particle Formulation in Spray Fluidized Beds

7.3 Influence of Material Properties

7.4 Influence of Operating Conditions

7.5 Influence of Apparatus Design

7.6 Neural Networks, Encapsulation

7.7 Stochastic Discrete Modeling of Agglomeration

7.8 Summary and Outlook

References

Index

Modern Drying Technology

Edited by E. Tsotsas and A. Mujumdar

Other Volumes

Volume 1: Computational Tools at Different Scales

ISBN: 978-3-527-31556-7

Volume 2: Experimental Techniques

ISBN: 978-3-527-31557-4

Forthcoming Volumes

Volume 4: Energy Savings

ISBN: 978-3-527-31559-8

Volume 5: Process Intensification

ISBN: 978-3-527-31560-4

Forthcoming Volumes

Modern Drying Technology Set (Volumes 1 – 5)

ISBN: 978-3-527-31554-3

The Editors:

Prof. Evangelos Tsotsas

Otto von Guericke University

Thermal Process Engineering

Universitätsplatz 2

39106 Magdeburg

Germany

Prof. Arun S. Mujumdar

National University of Singapore

Mecnical Engineering/Block EA 07-0

9 Engineering Drive 1

Singapore 117576

Singapore

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Library of Congress Card No.: applied for

British Library Cataloguing-in-Publication Data

A catalogue record for this book is available from the British Library.

Bibliographic information published by the Deutsche Nationalbibliothek

The Deutsche Nationalbibliothek lists this publication in the Deutsche Nationalbibliografie; detailed bibliographic data are available on the Internet at http://dnb.d-nb.de.

© 2011 Wiley-VCH Verlag & Co. KGaA, Boschstr. 12, 69469 Weinheim, Germany

All rights reserved (including those of translation into other languages). No part of this book may be reproduced in any form – by photoprinting, microfilm, or any other means – nor transmitted or translated into a machine language without written permission from the publishers. Registered names, trademarks, etc. used in this book, even when not specifically marked as such, are not to be considered unprotected by law.

ISBN: 978-3-527-31558-1

Series Preface

The present series is dedicated to drying, i.e. to the process of removing moisture from solids. Drying has been conducted empirically since the dawn of the human race. In traditional scientific terms it is a unit operation in chemical engineering. The reason for the continuing interest in drying and, hence, the motivation for the series concerns the challenges and opportunities. A permanent challenge is connected to the sheer amount and value of products that must be dried – either to attain their functionalities, or because moisture would damage the material during subsequent processing and storage, or simply because customers are not willing to pay for water. This comprises almost every material used in solid form, from foods to pharmaceuticals, from minerals to detergents, from polymers to paper. Raw materials and commodities with a low price per kilogram, but with extremely high production rates, and also highly formulated, rather rare but very expensive specialties have to be dried.

This permanent demand is accompanied by the challenge of sustainable development providing welfare, or at least a decent living standard, to a still-growing humanity. On the other hand, opportunities emerge for drying, as well as for any other aspect of science or living, from either the incremental or disruptive development of available tools. This duality is reflected in the structure of the book series, which is planned for five volumes in total, namely:

Volume 1: Computational tools at different scales

Volume 2: Experimental techniques

Volume 3: Product quality and formulation

Volume 4: Energy savings

Volume 5: Process intensification

As the titles indicate, we start with the opportunities in terms of modern computational and experimental tools in Volumes 1 and 2, respectively. How these opportunities can be used in fulfilling the challenges, in creating better and new products, in reducing the consumption of energy, in significantly improving existing or introducing new processes will be discussed in Volumes 3, 4 and 5. In this sense, the first two volumes of the series will be driven by science; the last three will try to show how engineering science and technology can be translated into progress.

In total, the series is designed to have both common aspects with and essential differences from an extended textbook or a handbook. Textbooks and handbooks usually refer to well-established knowledge, prepared and organized either for learning or for application in practice, respectively. On the contrary, the ambition of the present series is to move at the frontier of “modern drying technology”, describing things that have recently emerged, mapping things that are about to emerge, and also anticipating some things that may or should emerge in the near future. Consequently, the series is much closer to research than textbooks or handbooks can be. On the other hand, it was never intended as an anthology of research papers or keynotes – this segment being well covered by periodicals and conference proceedings. Therefore, our continuing effort will be to stay as close as possible to a textbook in terms of understandable presentation and as close as possible to a handbook in terms of applicability.

Another feature in common with an extended textbook or a handbook is the rather complete coverage of the topic by the entire series. Certainly, not every volume or chapter will be equally interesting for every reader, but we do hope that several chapters and volumes will be of value for graduate students, for researchers who are young in age or thinking, and for practitioners from industries that are manufacturing or using drying equipment. We also hope that the readers and owners of the entire series will have a comprehensive access not to all, but to many significant recent advances in drying science and technology. Such readers will quickly realize that modern drying technology is quite interdisciplinary, profiting greatly from other branches of engineering and science. In the opposite direction, not only chemical engineers, but also people from food, mechanical, environmental or medical engineering, material science, applied chemistry or physics, computing and mathematics may find one or the other interesting and useful results or ideas in the series.

The mentioned interdisciplinary approach implies that drying experts are keen to abandon the traditional chemical engineering concept of unit operations for the sake of a less rigid and more creative canon. However, they have difficulties of identification with just one of the two new major trends in chemical engineering, namely process-systems engineering or product engineering. Efficient drying can be completely valueless in a process system that is not efficiently tuned as a whole, while efficient processing is certainly valueless if it does not fulfil the demands of the market (the customer) regarding the properties of the product. There are few topics more appropriate in order to demonstrate the necessity of simultaneous treatment of product and process quality than drying. The series will try to work out chances that emerge from this crossroads position.

One further objective is to motivate readers in putting together modules (chapters from different volumes) relevant to their interests, creating in this manner individual, task-oriented threads trough the series. An example of one such thematic thread set by the editors refers to simultaneous particle formation and drying, with a focus on spray fluidized beds. From the point of view of process-systems engineering, this is process integration – several “unit operations” take place in the same equipment. On the other hand, it is product engineering, creating structures – in many cases nanostructures – that correlate with the desired application properties. Such properties are distributed over the ensemble (population) of particles, so that it is necessary to discuss mathematical methods (population balances) and numerical tools able to resolve the respective distributions in one chapter of Volume 1. Measuring techniques providing access to properties and states of the particle system will be treated in one chapter of Volume 2. In Volume 3, we will attempt to combine the previously introduced theoretical and experimental tools with the goal of product design. Finally, important issues of energy consumption and process intensification will appear in chapters of Volumes 4 and 5. Our hope is that some thematic combinations we have not even thought about in our choice of contents will arise in a similar way.

As the present series is a series of edited books, it can not be as uniform in either writing style or notation as good textbooks are. In the case of notation, a list of symbols has been developed and will be printed in the beginning of every volume. This list is not rigid but foresees options, at least partially accounting for the habits in different parts of the world. It has been recently adopted as a recommendation by the Working Party on Drying of the European Federation of Chemical Engineering (EFCE). However, the opportunity of placing short lists of additional or deviant symbols at the end of every chapter has been given to all authors. The symbols used are also explained in the text of every chapter, so that we do not expect any serious difficulties in reading and understanding.

The above indicates that the clear priority in the edited series was not in uniformity of style, but in the quality of contents that are very close to current international research from academia and, where possible, also from industry. Not every potentially interesting topic is included in the series, and not every excellent researcher working on drying contributes to it. However, we are very confident about the excellence of all research groups that we were able to gather together, and we are very grateful for the good cooperation with all chapter authors. The quality of the series as a whole is set mainly by them; the success of the series will primarily be theirs. We would also like to express our acknowledgements to the team of Wiley-VCH who have done a great job in supporting the series from the first idea to realization. Furthermore, our thanks go to Mrs Nicolle Degen for her additional work, and to our families for their tolerance and continuing support.

Last but not least, we are grateful to the members of the Working Party on Drying of the EFCE for various reasons. First, the idea about the series came up during the annual technical and business meeting of the working party 2005 in Paris. Secondly, many chapter authors could be recruited among its members. Finally, the Working Party continues to serve as a panel for discussion, checking and readjustment of our conceptions about the series. The list of the members of the working party with their affiliations is included in every volume of the series in the sense of acknowledgement, but also in order to promote networking and to provide access to national working parties, groups and individuals. The present edited books are complementary to the regular activities of the EFCE Working Party on Drying, as they are also complementary to various other regular activities of the international drying community, including well-known periodicals, handbooks, and the International Drying Symposia.

June 2007

Evangelos TsotsasArun S. Mujumdar

Preface of Volume 3

The first two volumes of this series have treated “Computational tools at different scales” and “Experimental techniques” that can empower “Modern Drying Technology” with the aim of producing superior products with better processes. Now, it is time to turn from the means to the goal, treating “Product quality and formulation” in Volume 3. This emphasis on the product is deliberate, because even the most efficient process is not of real value, if not able to fulfill – if not push – the requirements of the market. The topic is presented in seven chapters:

Chapter 1: Quality changes in food materials as influenced by drying processes

Chapter 2: Impact of drying on the mechanical properties and crack formation in rice

Chapter 3: Characterization and control of physical quality factors during freeze-drying of pharmaceuticals in vials

Chapter 4: In-line product quality control of pharmaceuticals in freeze-drying processes

Chapter 5: Understanding and preventing structural changes during drying of gels

Chapter 6: Morphology and properties of spray-dried particles

Chapter 7: Particle formulation in spray fluidized beds

Chapter 1 refers to a big, utterly important group of products to be dried, namely foods. It summarizes food properties, introduces the glass transition temperature as a humidity dependent landmark between the glassy and the rubbery state of amorphous materials, and discusses biochemical, physical and mechanical transformations that can take place during drying. Furthermore, it connects drying with quality changes during storage and with properties relevant to the final use of the processed food.

One good example of what can happen after drying is the fissuring and breakage of rice kernels due to stresses and strains that developed during the process. Therefore, this example is used in Chapter 2 in order to show how the previously discussed general principles can be cast into specific and precise characterization methods and models for the preservation of the quality of a valuable but perishable good.

In Chapter 3 the focus is shifted to pharmaceuticals, specifically to active ingredients with a high molecular weight, such as therapeutic proteins or enzymes. Such compounds are usually produced biotechnologically, so that they often have to be transformed from an aqueous solution to a solid form. This is commonly carried out by freezing and then freeze-drying, in order to protect the complex molecular structure from deterioration. The chapter discusses thoroughly, what kinds of damage can occur during the process, and how they can be avoided. And, it shows impressively, how intimate the interrelation of freeze-drying to the preceding process of freezing is. This interconnection results from the fact that the solid skeleton of freeze-dried cakes is created during freezing by the size and spatial placement of the ice crystals. Such causality offers rich opportunities of beneficial manipulation by changes in the freezing protocol, controlled nucleation or annealing, which are worked out in detail.

Though the degradation of pharmaceuticals during freeze-drying is not permissible too conservative an operation also should be avoided, because it is very expensive. The key for resolving this dilemma between product quality and process efficiency is monitoring and control. Consequently, methods that can be used for monitoring and control during freeze-drying of pharmaceuticals are presented in Chapter 4. This is done in a very comprehensive and precise way, distinguishing among methods that refer to single vials, groups of vials, and the entire dryer for the primary or the secondary period of drying. Close reference to process analytical technology (PAT) is given throughout.

Gels are a class of materials with high porosity, very small primary particle size, and a plethora of possible applications. However, such applications require that the gels can be dried without destroying the structures which are generic for their properties. This is not an easy task, because very small primary particles imply very high capillary forces during drying, so that the material can crack and break. Chapter 5 points out that convective drying may still be successful if applied in an educated way, and compares with numerous alternatives, such as freeze-drying and supercritical drying. Apart from the detailed discussion of processing options, the preparation and the characterization of gel materials are elucidated.

Though the preservation of existing structures is a big goal, structures and the conjugated properties can even be created by drying. This is always the case when the removal of water or some other solute is accompanied by the formation of the solid phase, as in spray drying, which is treated comprehensively in Chapter 6. This chapter refers to solutions of components with a low or high molecular weight, as well as to suspensions of small or large particles, and shows how drying conditions and material properties influence the morphology of the resulting products. Methods of formulation by encapsulation of, for example, flavors or enzymes, are presented in detail, including stability and quality of the obtained products.

The idea of formulation by drying is elaborated further in Chapter 7. Here, drying after spraying on fluidized particles with the aim of producing agglomerates, layered granules, or coatings is discussed. It is worked out on many examples, how the processes and the products can be enhanced by manipulation of material properties, operating conditions, and apparatus design. The physical background is explained down to the molecular scale in order to derive conditions for adhesion around small particle contacts. Understanding and characterization of properties relevant to the processing or final use of the particles are, again, important issues. Furthermore, modeling tools with different degrees of resolution and sophistication – such as discrete particle modeling, Monte Carlo simulations, and neural networks – which can separately or in combination support process and product development are presented.

Readers looking for thematic threads within the Modern Drying Technology series will easily recognize many, including those between the present:

– Chapter 1 and Chapter 2 of Vol. 2 (drying of foods)

– Chapters 2 and 5 and Chapters 3 and 4 of Vol. 1 (thermo-mechanics)

– Chapter 4 and Chapter 1 of Vol. 2 (monitoring)

– Chapter 5 and Chapter 3 of Vol. 2 (x-ray tomography)

– Chapter 6 and Chapter 5 of Vol. 1 (spray drying)

– Chapter 7 and Chapter 6 of Vol. 1, as well as Chapter 5 of Vol. 2 (fluidized bed formulation)

Readers interested in transport phenomena at different scales will find molecular, pore-scale, particle-scale and particle system or processing equipment considerations, as in every volume of the series, and those aiming at interdisciplinary approaches will see clear links to food engineering, pharmaceutical technology, biotechnology, mechanics, and material science. People looking for their specific product may not be able to find it in the present volume, but they may learn from methods and approaches successfully applied to other products. For a book without encyclopedic ambitions, which aims at the educated use of modern scientific methods in practice, this would be the biggest success.

As to the acknowledgements, for Volume 3 they are identical to those in the series preface. We would like to stress them by reference and not repeat them here.

June 2011

Evangelos TsotsasArun S. Mujumdar

List of Contributors

Editors

Prof. Evangelos Tsotsas Otto von Guericke University Magdeburg Thermal Process Engineering PSF 4120 39106 Magdeburg Germany Email: [email protected]

Prof. Arun S. Mujumdar Dept. of Mechanical Engineering 9 Engineering Drive 1 Singapore 117576 Singapore Email: [email protected]

Authors

Prof. Julien Andrieu Université C. Bernard - Lyon1/ E.S.C.P.E. Laboratoire d'Automatique et de Génie des Procédés (LAGEP) UMR Q 5007 CNRS UCB Bâtiment 308G 43 boulevard du 11 Novembre 1918 69622 Villeurbanne Cedex France Email: [email protected]

Dr. Sergiy Antonyuk Technical University Hamburg-Harburg Solids Process Engineering and Particle Technology 21073 Hamburg Germany Email: [email protected]

Prof. Antonello A. Barresi Politecnico di Torino Dipartimento di Scienza dei Materiali e Ingegneria Chimica Corso Duca degli Abruzzi 24 10129 Torino Italy Email: [email protected]

Dr. Catherine Bonazzi INRA/AgroParisTech UMR1145 Ingénierie Procédés Aliments 1 avenue des Olympiades 91300 Massy France Email: [email protected]

Dr. Francis Courtois INRA/AgroParisTech UMR1145 Ingénierie Procédés Aliments 1 avenue des Olympiades 91300 Massy France Email: [email protected]

Prof. Elisabeth Dumoulin INRA/AgroParisTech UMR1145 Ingénierie Procédés Aliments 1 avenue des Olympiades 91300 Massy France Email: [email protected]

Dr. Davide Fissore Politecnico di Torino Dipartimento di Scienza dei Materiali e Ingegneria Chimica Corso Duca degli Abruzzi 24 10129 Torino Italy Email: [email protected]

Prof. Takeshi Furuta Tottori University Department of Chemistry and Biotechnology Graduate School of Engineering 4-101, Koyama-minami Tottori, 680-8552 Japan Email: [email protected]

Prof. Stefan Heinrich Technical University Hamburg-Harburg Solids Process Engineering and Particle Technology 21073 Hamburg Germany Email: [email protected]

Dip.-Ing. Michael Jacob Glatt Ingenieurtechnik GmbH Nordslrasse 12 99427 Weimar Germany Email: [email protected]

Prof. Wahbi Jomaa University Bordeaux 1 Laboratory TREFLE Esplanade des Arts et Métiers 33405 Talence France Email: [email protected]

Prof. Angélique Léonard Laboratoire de Génie Chimique Département de Chimie Appliquée Université de Liège Bâtiment B6c - Sart-Tilman 4000 Liège Belgium Email: [email protected]

Jun.-Prof. Thomas Metzger Otto von Guericke University Magdeburg Thermal Process Engineering PSF 4120 39106 Magdeburg Germany Email: [email protected]

Prof. Stefan Palzer Nestlé Product Technology Centre York Nestec York Ltd P.O. Box 204 Haxby Road York YO 91 1XY United Kingdom Email: [email protected]

Jun.-Prof. Mirko Peglow Otto von Guericke University Magdeburg Thermal Process Engineering PSF 4120 39106 Magdeburg Germany Email: [email protected]

Prof. Hajime Tamon Department of Chemical Engineering Kyoto University Katsura Kyoto 615-8510 Japan Email: [email protected]

Prof. Evangelos Tsotsas Otto von Guericke University Magdeburg Thermal Process Engineering PSF 4120 39106 Magdeburg Germany Email: [email protected]

Dr. Séverine Vessot Laboratoire d'Automatique et de Génie des Precédés (LAGEP) UMR Q 5007 CNRS UCB Lyon1-CPE Bât. 308G, 43 Bd. du 11 Novembre 1918 69622 Villeurbanne Cedex France Email: [email protected]

Prof. Peter Walzel Universität Dortmund Fachbereich Bio- und Chemieingenieurwesen Particle Technology Emil Figge Str. 68 44227 Dortmund Germany Email: [email protected]

EFCE Working Party on Drying: Address List

Dr. Odilio Alves-Filho Norwegian University of Science and Technology Department of Energy and Process Engineering Kolbjrn Hejes vei 1B 7491 Trondheim [email protected]

Prof. Julien Andrieu (delegate) UCB Lyon I/ESCPE LAGEP UMR CNRS 5007 batiment 308 G 43 boulevard du 11 novembre 1918 69622 Villeurbanne cedex [email protected]

Dr. Ir. Paul Avontuur Glaxo Smith Kline New Frontiers Science Park H89 Harlow CM19 5AW [email protected]

Prof. Christopher G. J. Baker Drying Associates Harwell International Business Centre 404/13 Harwell Didcot Oxfordshire OX11 ORA [email protected]

Prof. Antonello Barresi (delegate) Politecnico di Torino Dip. Scienza dei Materiali e Ingegneria Chimica Corso Duca degli Abruzzi 24 10129 Torino [email protected]

Dr. Rainer Bellinghausen (delegate) Bayer Technology Services GmbH BTS-PT-PT-PDSP Building E 41 51368 Leverkusen [email protected]

Dr. Carl-Gustav Berg Abo Akademi Process Design Laboratory Biskopsgatan 8 20500 Abo [email protected]

Dr. Catherine Bonazzi (delegate) AgroParisTech – INRA JRU for Food Process Engineering 1, Avenue des Olympiades 91744 Massy cedex [email protected]

Paul Deckers M.Sc. (delegate) Bodec, Process Optimization and Development Industrial Area't Zand Bedrijfsweg 1 5683 CM Best The [email protected]

Prof. Stephan Ditchev University of Food Technology 26 Maritza Blvd 4002 Plovdiv [email protected]

Dr. German I. Efremov Pavla Korchagina 22 129278 Moscow [email protected]

Prof. Trygve Eikevik Norwegian University of Science and Technology Department of Energy and Process Engineering Kolbjrn Hejes vei 1B 7491 Trondheim [email protected]

Dr.-Ing. Ioannis Evripidis Dow Deutschland GmbH & Co. OHG P.O. Box 1120 21677 Stade [email protected]

Prof. Dr. Istvan Farkas (delegate) Szent Istvan University Department of Physics and Process Control Pater K. u. 1. 2103 Godollo [email protected]

Dr.-Ing. Dietrich Gehrmann Wilhelm-Hastrich-Str. 12 51381 Leverkusen [email protected]

Prof. Dr.-Ing. Adrian-Gabriel Ghiaus (delegate) Technical University of Civil Engineering Thermal Engineering Department Bd. P. Protopopescu 66 021414 Bucharest [email protected]

Prof. Dr.-Ing. Gheorghita Jinescu University “Politehnica” din Bucuresti Faculty of Industrial Chemistry, Department of Chemical Engineering 1, Polizu street Building F Room F210 78126 Bucharest [email protected]

Prof. Dr. Gligor Kanevce St. Kliment Ohridski University Faculty of Technical Sciences ul. Ivo Ribar Lola b.b. Bitola FYR of [email protected]

Prof. Dr. Markku Karlsson (delegate) UPM-Kymmene Corporation P.O. Box 380 00101 Helsinki [email protected]

Ir. Ian C. Kemp (delegate) GMS, GSK Priory Street Ware, SG12 0XA [email protected]

Prof. Dr. Ir. P.J.A.M. Kerkhof Eindhoven University of Technology Department of Chemical Engineering P.O. Box 513 5600 MB Eindhoven The [email protected]

Prof. Matthias Kind Universität Karlsruhe (TH) Institut für Thermische Verfahrenstechnik Kaiserstr. 12 76128 Karlsruhe [email protected]

Prof. Eli Korin Ben-Gurion University of the Negev Chemical Engineering Department Beer-Sheva 84105 [email protected]

Emer. Prof. Ram Lavie Technion – Israel Institute of Technolgy Department of Chemical Engineering Technion City Haifa 32000 [email protected]

Dr. Ir. Angélique Léonard (delegate) Université de Liège, Département de Chimie Appliquée Laboratoire de Génie Chimique Bâtiment B6c - Sart-Tilman 4000 Liège [email protected]

Jean-Claude Masson RHODIA, Recherches et Technologies 85 avenue des Frères Perret BP 62 69192 Saint-Fons Cedex [email protected]

Prof. Natalia Menshutina Mendeleev University of Chemical Technology of Russia (MUCTR) High Technology Department 125047 Muisskaya sq.9 Moscow [email protected]

Jun.-Prof. Dr. Thomas Metzger Otto-von-Guericke-University Thermal Process Engineering P.O. Box 4120 39016 Magdeburg [email protected]

Prof. Antonio Mulet Pons (delegate) Universitat Politecnica de Valencia Departament de Tecnologia d'Aliments Cami de Vera s/n 46071 Valencia [email protected]

Prof. Zdzislaw Pakowski (delegate) Technical University of Lodz Faculty of Process and Environmental Engineering ul. Wolczanska 213 93-005 Lodz [email protected]

Prof. Patrick Perré (delegate, chairman of WP) AgroParisTech 14 Rue Girardet 54042 Nancy [email protected]

Dr. Roger Renström Karlstad University Department of Environmental and Energy Systems Universitetsgatan 2 65188 Karlstad Sweden [email protected]

Prof. Michel Roques Université de Pau et des Pays de l'Adour ENSGTI, 5 rue Jules- Ferry 64000 Pau [email protected]

Dr. Carmen Rosselló (delegate) University of Iles Baleares Dep. Quimica Ctra Valldemossa km 7.5 07122 Palme Mallorca [email protected]

Emer. Prof. G. D. Saravacos (delegate) Nea Tiryntha 21100 Nauplion [email protected]

Dr.-Ing. Michael Schönherr BASF, GCT/T - L 540 Research Manager Drying Process Engineering 67056 Ludwigshafen [email protected]

Prof. Dr.-Ing. Ernst-Ulrich Schlünder Lindenweg 10 76275 Ettlingen [email protected]

Dr. Alberto M. Sereno (delegate) University of Porto Department of Chemical Engineering Rua Dr Roberto Frias 4200-465 Porto [email protected]

Dr. Milan Stakic Vina Institute for Nuclear Sciences Center NTI P.O. box 522 11001 Belgrade [email protected]

Prof. Stig Stenstrom (delegate) Lund University Institute of Technology Department of Chemical Engineering P.O. Box 124 22100 Lund [email protected]

Prof. Ingvald Strommen (delegate) Norwegian University of Science and Technology Department of Energy and Process Engineering Kolbjrn Hejes vei 1b 7491 Trondheim [email protected]

Prof. Czeslaw Strumillo (delegate) Technical University of Lodz Faculty of Process and Environmental Engineering Lodz Technical University ul. Wolczanska 213 93-005 Lodz [email protected]

Prof. Radivoje Topic (delegate) University of Belgrade Faculty of Mechanical Engineering 27, marta 80 11000 Beograd [email protected]

Prof. Dr.-Ing. Evangelos Tsotsas (delegate, former chairman of WP) Otto-von-Guericke-University Thermal Process Engineering P.O. Box 4120 39016 Magdeburg [email protected]

Dr. Henk C. van Deventer (delegate) TNO Quality of Life P.O. Box 342 7300 AH Apeldoorn The [email protected]

Michael Wahlberg M.Sc. Niro Gladsaxevej 305 2860 Soeborg [email protected]

Prof. Roland Wimmerstedt Lund University Institute of Technology Department of Chemical Engineering P.O. Box 124 22100 Lund [email protected]

Dr. Bertrand Woinet (delegate) SANOFI-CHIMIE, CDP bât. 8600 31-33 quai armand Barbès 69583 Neuville sur Saône cedex [email protected]

Prof. Ireneusz Zbicinski Lodz Technical University Faculty of Process and Environmental Engineering ul. Wolczanska 213 93-005 Lodz [email protected]

Chapter 1

Quality Changes in Food Materials as Influenced by Drying Processes

Catherine Bonazzi and Elisabeth Dumoulin

1.1 Introduction

Drying and dewatering plays a major role in food manufacturing or food processing activities worldwide. Often one of the last operations in the food processing, it controls to a large extent the quality of the final product. Drying is applied to a wide variety of food products, from cereals to finished goods, from raw materials to by-products. The processes used are numerous, according to the type and quantity of product to dry, the amount of water to eliminate, the final desired quality or functionality of the dried product (Tab. 1.1).

Tab. 1.1 Diversity of drying equipment and products in the food industry.

EquipmentProductsDrum dryerthick liquids, pulps, pastes or slurries: mashed potatoes, carrots, baby cereals, soups, starchRotary dryerparticulate solid foods: alfalfa, pasta, sugar beet pulp, pomace, starch, whey, pectin residues, lemon pulps, and so on.Deep bed/dihedral dryercereals: malt, maize, sunflower grain, rice, wheatSpray dryerliquids: milk, whey, coffee, tea, yeastPneumatic dryerfor the finish drying of powders or granulated materials: starch, flour, proteins, distillery residues, aspartame, guar gum, methionineTunnel conveyor, belt or band dryer