Cauvain Bread Making

Improving Quality
1. Auflage 2003
ISBN: 978-1-85573-712-9
Verlag: Elsevier Science & Techn.
Format: EPUB
Kopierschutz: Adobe DRM (»Systemvoraussetzungen)

E-Book, Englisch, 608 Seiten

Reihe: Woodhead Publishing Series in Food Science, Technology and Nutrition

There has been a wealth of recent research on the complex changes involved in bread making and how they influence the many traits consumers use to define quality. Bread making: improving quality sums up this key research and what it means for improved process control and a better, more consistent product.After an introductory review of bread making as a whole part one discusses wheat and flour quality. Chapter 3 summarises current research on the structure of wheat, providing the context for chapters on wheat proteins (chapters 5 and 6) and starch (chapter 7). There are also chapters on ways of measuring wheat and flour quality, and improving flour for bread making. Part two reviews dough formation and its impact on the structure and properties of bread. It includes chapters on the molecular structure of dough, foam formation and bread aeration together with discussion of the role of key ingredients such as water. A final group of chapters then discusses other aspects of quality such as improving taste and nutritional properties, as well as preventing moulds and mycotoxin contamination.With its distinguished editor and international team of contributors, Bread making: improving quality is a standard work both for industry and the research community.

Autoren/Hrsg.

Cauvain, Stanley P.

Inhaltsverzeichnis

1;Front Cover;1
2;Bread Making: Improving Quality;4
3;Copyright Page
;5
4;Table of Contents;6
5;Contributor contact details;14
6;Chapter 1. Introduction;20
6.1;1.1 Wheat and its special properties;21
6.2;1.2 Converting wheat to flour;22
6.3;1.3 Making bread;23
6.4;1.4 Functional ingredients;24
6.5;1.5 Bread in the future;25
6.6;1.6 References;26
7;Chapter 2. Breadmaking: an overview;27
7.1;2.1 Introduction;27
7.2;2.2 Bread dough development;29
7.3;2.3 Breadmaking processes;30
7.4;2.4 What determines bread quality?;33
7.5;2.5 Dough mixing and processing;36
7.6;2.6 Cell creation during mixing;38
7.7;2.7 Dough processing;39
7.8;2.8 Gas bubble control during dough processing;42
7.9;2.9 Proving and baking;43
7.10;2.10 Future trends;45
7.11;2.11 Sources of further information and advice;46
7.12;2.12 References;46
8;Part I: Wheat and flour quality;48
8.1;Chapter 3. The chemistry and biochemistry of wheat;50
8.1.1;3.1 Introduction: the structure of the wheat kernel;50
8.1.2;3.2 Wheat carbohydrates;53
8.1.3;3.3 Wheat proteins;63
8.1.4;3.4 Wheat lipids;76
8.1.5;3.5 Wheat enzymes;79
8.1.6;3.6 Pigments;80
8.1.7;3.7 Future trends in wheat utilisation;80
8.1.8;3.8 Sources of further information and advice;84
8.1.9;3.9 References;85
8.2;Chapter 4. Assessing grain quality;90
8.2.1;4.1 Introduction: the interaction of genotype with the environment;90
8.2.2;4.2 The importance of variety;92
8.2.3;4.3 Environmental factors affecting grain quality;95
8.2.4;4.4 Storage and transport;98
8.2.5;4.5 Critical quality attributes and their analysis;99
8.2.6;4.6 Grain quality bargaining;110
8.2.7;4.7 Future trends;111
8.2.8;4.8 Sources of further information and advice;111
8.2.9;4.9 References;111
8.3;Chapter 5. Techniques for analysing wheat proteins;116
8.3.1;5.1 Introduction;116
8.3.2;5.2 Separation methods;117
8.3.3;5.3 Analysing molecular properties;118
8.3.4;5.4 Rheological measurements;120
8.3.5;5.5 Infrared spectroscopy;122
8.3.6;5.6 NMR spectroscopy;124
8.3.7;5.7 Electron spin resonance spectroscopy;130
8.3.8;5.8 Future trends;132
8.3.9;5.9 References;134
8.4;Chapter 6. Wheat proteins and bread quality;140
8.4.1;6.1 Introduction: cereal protein classification;140
8.4.2;6.2 Cereal proteins and breadmaking quality;147
8.4.3;6.3 Prolamin structure and bread quality;148
8.4.4;6.4 Soluble proteins, xylanase inhibitors and bread quality;152
8.4.5;6.5 Detergent-solubilised proteins and bread quality;154
8.4.6;6.6 Genomics and the wheat grain proteome;155
8.4.7;6.7 Conclusion and future trends;158
8.4.8;6.8 Acknowledgements;158
8.4.9;6.9 References;158
8.5;Chapter 7. Starch structure and bread quality;164
8.5.1;7.1 Introduction: the importance of starch structure to bread quality;164
8.5.2;7.2 Starch properties and baking performance;165
8.5.3;7.3 Starch structure;170
8.5.4;7.4 Starch structure and bread quality;175
8.5.5;7.5 Future trends;179
8.5.6;7.6 Sources of further information and advice;180
8.5.7;7.7 References;180
8.6;Chapter 8. Improving wheat quality: the role of biotechnology;187
8.6.1;8.1 Introduction;187
8.6.2;8.2 Wheat gluten proteins;187
8.6.3;8.3 HMW subunits and bread quality;190
8.6.4;8.4 The genetic transformation of wheat;194
8.6.5;8.5 Manipulating HMW subunit composition and dough properties;196
8.6.6;8.6 Future trends: improving bread quality;199
8.6.7;8.7 Sources of further information and advice;201
8.6.8;8.8 Acknowledgements;201
8.6.9;8.9 References;201
8.7;Chapter 9. Analysing wheat and flour;206
8.7.1;9.1 Introduction;206
8.7.2;9.2 Sample collection and preparation;208
8.7.3;9.3 Grain quality parameters;208
8.7.4;9.4 Flour quality: protein;210
8.7.5;9.5 Flour quality: starch and other attributes;214
8.7.6;9.6 Conclusion;216
8.7.7;9.7 Sources of further information and advice;216
8.7.8;9.8 References;217
8.8;Chapter 10. Milling and flour quality;219
8.8.1;10.1 Introduction;219
8.8.2;10.2 Flour milling;220
8.8.3;10.3 Flour milling and flour quality;229
8.8.4;10.4 Milling research;235
8.8.5;10.5 The future of flour milling;236
8.8.6;10.6 Conclusion;237
8.8.7;10.7 References;237
8.9;Chapter 11. Modifying flour to improve functionality;239
8.9.1;11.1 Introduction;239
8.9.2;11.2 Definition of some key terms and components;240
8.9.3;11.3 Protein modification and breadmaking quality;244
8.9.4;11.4 Genetic modification of flour properties;262
8.9.5;11.5 References;265
8.10;Chapter 12. The nutritional enhancement of wheat flour;272
8.10.1;12.1 Introduction;272
8.10.2;12.2 The nutritional value of wheat;274
8.10.3;12.3 Increasing the nutritional value of wheat flour;276
8.10.4;12.4 Improving the nutritional value of wholewheat flours;281
8.10.5;12.5 Future trends: protein supplementation and fibre enhancement;282
8.10.6;12.6 Sources of further information and advice;285
8.10.7;12.7 References;285
9;Part II: Dough and bread quality;290
9.1;Chapter 13. The molecular basis of dough rheology;292
9.1.1;13.1 Introduction;292
9.1.2;13.2 Factors affecting dough rheology;293
9.1.3;13.3 Polymer networks in doughs;296
9.1.4;13.4 The molecular mechanism of energy storage in dough;298
9.1.5;13.5 How much dough rheology can we explain?;302
9.1.6;13.6 Future trends;303
9.1.7;13.7 Sources of further information and advice;304
9.1.8;13.8 Acknowledgement;305
9.1.9;13.9 References;305
9.2;Chapter 14. Molecular mobility in dough and bread quality;307
9.2.1;14.1 Introduction;307
9.2.2;14.2 Molecular mobility in dough;308
9.2.3;14.3 Dough properties in baking;314
9.2.4;14.4 Controlling molecular mobility to improve bread quality;317
9.2.5;14.5 Future trends;320
9.2.6;14.6 Sources of further information and advice;321
9.2.7;14.7 References;321
9.3;Chapter 15. The role of water in dough formation and bread quality;325
9.3.1;15.1 Introduction;325
9.3.2;15.2 Dough as a disperse system;326
9.3.3;15.3 Water displacements in dough;328
9.3.4;15.4 Dough proofing and baking;331
9.3.5;15.5 Dough freezing;334
9.3.6;15.6 Future trends;336
9.3.7;15.7 Sources of further information and advice;336
9.3.8;15.8 References;337
9.4;Chapter 16. Foam formation in dough and bread quality;340
9.4.1;16.1 Introduction;340
9.4.2;16.2 Foam formation;341
9.4.3;16.3 Foam stability;343
9.4.4;16.4 Surface active dough components;347
9.4.5;16.5 The aqueous phase of dough and foam formation;349
9.4.6;16.6 Dough composition and foam stability;352
9.4.7;16.7 Processing stages and foam stability;358
9.4.8;16.8 Analytical techniques;359
9.4.9;16.9 Future trends;363
9.4.10;16.10 Sources of further information and advice;364
9.4.11;16.11 References;365
9.5;Chapter 17. Bread aeration;371
9.5.1;17.1 Introduction;371
9.5.2;17.2 The development of bread aeration studies;374
9.5.3;17.3 Aeration during breadmaking: mixing;376
9.5.4;17.4 Aeration during proving;380
9.5.5;17.5 Aeration during baking;383
9.5.6;17.8 Acknowledgements;388
9.5.7;17.9 Further reading;388
9.5.8;17.10 References;390
9.6;Chapter 18. Measuring the rheological properties of dough;394
9.6.1;18.1 Introduction: dough rheology and bread quality;394
9.6.2;18.2 The role of rheology in quality control;396
9.6.3;18.3 Rheological tests;397
9.6.4;18.4 Descriptive rheological measurements;399
9.6.5;18.5 Fundamental rheological tests;401
9.6.6;18.6 Baking quality and rheology;408
9.6.7;18.7 Future trends;414
9.6.8;18.8 References;414
9.7;Chapter 19. Controlling dough development;420
9.7.1;19.1 Introduction;420
9.7.2;19.2 Dough rheology during mixing;421
9.7.3;19.3 Dough development;423
9.7.4;19.4 The effects of mixer type;425
9.7.5;19.5 Controlling dough development;427
9.7.6;19.6 Emerging methods for controlling dough development;432
9.7.7;19.7 Future trends;438
9.7.8;19.8 Sources of further information and advice;438
9.7.9;19.9 References;440
9.8;Chapter 20. The use of redox agents;443
9.8.1;20.1 Introduction;443
9.8.2;20.2 The redox state in flour;444
9.8.3;20.3 Redox reactions during processing;450
9.8.4;20.4 Redox agents: oxidants and reductants;454
9.8.5;20.5 Future trends;461
9.8.6;20.6 Sources of further information and advice;462
9.8.7;20.7 References;462
9.9;Chapter 21. Water control in baking;466
9.9.1;21.1 Introduction: water composition and properties;466
9.9.2;21.2 Hygrometry and water hardness;469
9.9.3;21.3 The water absorption capacity of flour;471
9.9.4;21.4 Dough formation;472
9.9.5;21.5 Proving and baking;476
9.9.6;21.6 Water activity and the shelf-life of bread;481
9.9.7;21.7 Future trends;483
9.9.8;21.8 Sources of further information and advice;484
9.9.9;21.9 References;484
9.10;Chapter 22. Improving the taste of bread;486
9.10.1;22.1 Introduction;486
9.10.2;22.2 Elements of bread flavor;488
9.10.3;22.3 Ingredients and flavor: flour and water;490
9.10.4;22.4 Ingredients and flavor: yeast and lactic acid fermentation;493
9.10.5;22.5 Processing and flavor: mixing, fermentation and baking;495
9.10.6;22.6 Innovations in bread flavor;497
9.10.7;22.7 References;503
9.11;Chapter 23. High-fibre baking;506
9.11.1;23.1 Introduction;506
9.11.2;23.2 Sources of fibre in baking;507
9.11.3;23.3 Problems in high-fibre baking;509
9.11.4;23.4 Improving the quality of high-fibre bread;511
9.11.5;23.5 Future trends;515
9.11.6;23.6 References;516
9.12;Chapter 24. Mould prevention in bread;519
9.12.1;24.1 Introduction: the problem of mould in bread;519
9.12.2;24.2 Current techniques for mould control and their limitations;521
9.12.3;24.3 Developing new methods for mould control;524
9.12.4;24.4 Future trends;529
9.12.5;24.5 Sources of further information and advice;530
9.12.6;24.6 References;530
9.13;Chapter 25. Detecting mycotoxin contamination of cereals;534
9.13.1;25.1 Introduction: the problem of mycotoxin contamination;534
9.13.2;25.2 Mycotoxins in the food chain;535
9.13.3;25.3 Detecting mycotoxins;541
9.13.4;25.4 The regulatory context;546
9.13.5;25.5 Future trends;547
9.13.6;25.6 References;549
9.14;Chapter 26. Improving wheat quality;555
9.14.1;26.1 Introduction;555
9.14.2;26.2 US wheat classification and grading;556
9.14.3;26.3 Breeding and wheat quality;559
9.14.4;26.4 Quality indices and tests;562
9.14.5;26.5 Predicting the breadmaking quality of wheat;568
9.14.6;26.6 Future trends;573
9.14.7;26.7 References;576
9.15;Chapter 27. Preventing bread staling;581
9.15.1;27.1 Introduction;581
9.15.2;27.2 Economic significance of staling;581
9.15.3;27.3 The process of bread staling;582
9.15.4;27.4 Factors affecting bread staling;582
9.15.5;27.5 Techniques for preventing bread staling;587
9.15.6;27.6 Future trends;589
9.15.7;27.7 Sources of further information and advice;589
9.15.8;27.8 References;590
10;Index;594

Leseproben

2 Breadmaking: an overview
S. Cauvain    Campden and Chorleywood Food Research Association, UK 2.1 Introduction
Bread is a staple foodstuff, which is made and eaten in most countries around the world. Bread products have evolved to take many forms, each based on quite different and distinctive characteristics. Over the centuries craft bakers have developed our traditional bread varieties using their accumulated knowledge as to how to make best use of their available raw materials to achieve the desired bread quality. In some countries the nature of breadmaking has retained its traditional form while in others it has changed dramatically. The proliferation of bread varieties derives from the unique properties of wheat proteins to form gluten and from the bakers’ ingenuity in manipulating the gluten structures formed within the dough. The rubbery mass of gluten with its ability to deform, stretch, recover shape and trap gases is very important in the production of bread and all fermented products. Of all the cereals, wheat is almost unique in this respect. The term ‘bread’ is used to describe such a wide range of products with different shapes, sizes, textures, crusts, colours, softness, eating qualities and flavours that the terms ‘good’ or ‘bad’ quality tend to have no real meaning, except to the individual making the assessment. A baguette is not a baguette without a crisp crust, while the same crust formation would be unacceptable on north American pan bread and the fine cell structure of sandwich bread in the UK has no relevance to the flat breads of the Middle East. The character of bread and other fermented products depends heavily on the formation of a gluten network which traps gas from yeast fermentation and makes a direct contribution to the formation of a cellular crumb structure which, after baking, confers texture and eating qualities quite different from other baked products. Look closely at the crumb structures of most baked breads and you will see that the common linking theme is that they are formed of holes of differing shapes, sizes and distributions. Each hole is embraced by a network of connected strands, coagulated gluten, in which starch granules and bran particles are firmly embedded. When this crumb is subjected to pressure with the fingers it deforms, and when the force is removed it springs back to assume its original shape, at least when the product is fresh. This combination of a cellular crumb with the ability to recover after being compressed largely distinguishes breads from other baked products: these are the very characteristics that bakers seek to achieve in most bread products. While there are many different breadmaking processes, they have the common aim of converting wheat flour and other ingredients into a light, aerated and palatable food. The move to improve the digestibility of the wild grass seed forerunners of early wheat types through fermentation and baking represents a major step in the development of human food production. The unique properties of the proteins in wheat with their ability to form a cohesive mass of dough once the flour has been hydrated and subjected to the energy of mixing, even by hand, provides the basis of the transition from flour to bread. This cohesive mass is the one bakers call ‘gluten’ and once it has formed into a dough it has the ability to trap gases during fermentation, proof and baking which allows the mass to expand to become a softer, lighter and more palatable as a food after baking. The discovery that dough left for long periods of time would increase in volume without being subjected to the high temperatures of baking identified the basis of fermentation. The combined effect of these rheological changes is for the baked mass to increase in volume and give a product with an even softer, more digestible character and different flavour. There are a few basic steps that form the basis of all breadmaking. They can be listed as follows: • The mixing of wheat flour and water, together with yeast and salt, and other specified ingredients in appropriate ratios. • The development of a gluten structure in the dough through the application of energy during mixing. • The incorporation of air bubbles within the dough during mixing. • The continued ‘development’ of the gluten structure created in order to modify the rheological properties of the dough and to improve its ability to expand when gas pressures increase during fermentation. • The creation and modification of particular flavour compounds in the dough. • Thesubdivision of the dough mass into unit pieces. • A preliminary modification of the shape of the divided piece. • A short delay in processing to further modify physical and rheological properties of the dough pieces. • The shaping of the dough pieces to their required shape. • The fermentation and expansion of the shaped dough pieces during proof. • Further expansion of the dough pieces and fixation of the final bread structure during baking. • Cooling and storage of the final product before consumption. Loss of product freshness is as much about what we expect a product character to be as it is about its age since original manufacture. Whatever the criteria we use to judge bread staleness it becomes clear that the single most common requirement of fermented products is that it should ideally retain all of the attributes that it had when it left the oven; above all else we expect our bread to be ‘fresh’. When we collect our bread from the baker and it is still warm to the touch we have no doubt as to its freshness, but when we purchase it cold from the store shelf we need convincing as to its freshness. Raw materials and the processes used change and are time and temperature sensitive. To be able to make our particular bread type we must have an understanding of the complex interactions between our raw materials and the methods we will use in the conversion processes from ingredients to baked product. 2.2 Bread dough development
Dough development is a relatively undefined term that covers a number of complex changes that begin when the ingredients first become mixed. These changes are associated with the formation of gluten, which requires both the hydration of the proteins in the flour and the application of energy through the process of kneading. The role of energy in the formation of gluten is not always fully appreciated but it is a significant contributor to the breadmaking process. There is more to dough development than a simple kneading process. The process of developing bread dough brings about changes in the physical properties of the dough and in particular improvement in its ability to retain the carbon dioxide gas which will later be generated by yeast fermentation. This improvement in gas retention ability is particularly important when the dough pieces reach the oven. In the early stages of baking before the dough has set, yeast activity is at its greatest and large quantities of carbon dioxide gas are being generated and released from solution in the aqueous phase of the dough. If the dough pieces are to continue to expand at this time then the dough must be able to retain a large quantity of that gas being generated and it can do this only if we have created a gluten structure with the appropriate physical properties. It is important to distinguish between gas production and gas retention in fermented dough. Gas production refers to the generation of carbon dioxide gas as a natural consequence of yeast fermentation. Provided the yeast cells in the dough remain viable and there is sufficient substrate, then gas production will continue, but expansion of the dough can occur only if that carbon dioxide gas is retained in the dough. Not all of the gas generated during the breadmaking process will be retained within the dough before it finally sets in the oven. The proportion that will be retained depends on the development of a suitable gluten matrix within which the expanding gas can be held. Gas retention in dough is therefore closely linked with the degree of dough development. The most commonly considered factors are those related to the protein component of wheat flour; however, dough development will be affected by a large number of ingredients and processing parameters, many of which are not necessarily independent of one another. 2.3 Breadmaking processes
The development of no-time (i.e. no resting time in bulk before dividing) dough-making processes changed traditional (pre-1960) breadmaking. Foremost in these changes was the invention of the Chorleywood Bread Process (CBP) in which the development of optimum dough qualities is achieved in the mixer by measuring a defined energy expenditure rather than through the effects of fermentation (Cauvain, 1998). The result of the introduction of the CBP was to eliminate the need for bulk fermentation periods with considerable raw material and time savings, as well as to initiate changes in ingredient and processing technologies. The principles of the CBP were adopted in many countries around the world (Gould,...