Breadmaking

Improving Quality

Stanley P. Cauvain

• Publisher: Woodhead Publishing
• Year: 2012
• eBook ISBN: 9780857095695
• Edition: 2
• Topic: Technology & Engineering
• Subtopic: Food Science
• Index: Technology & Engineering

The first edition of Breadmaking: Improving quality quickly established itself as an essential purchase for baking professionals and researchers in this area. With comprehensively updated and revised coverage, including six new chapters, the second edition helps readers to understand the latest developments in bread making science and practice.The book opens with two introductory chapters providing an overview of the breadmaking process. Part one focuses on the impacts of wheat and flour quality on bread, covering topics such as wheat chemistry, wheat starch structure, grain quality assessment, milling and wheat breeding. Part two covers dough development and bread ingredients, with chapters on dough aeration and rheology, the use of redox agents and enzymes in breadmaking and water control, among other topics. In part three, the focus shifts to bread sensory quality, shelf life and safety. Topics covered include bread aroma, staling and contamination. Finally, part four looks at particular bread products such as high fibre breads, those made from partially baked and frozen dough and those made from non-wheat flours.With its distinguished editor and international team of contributors, the second edition of Breadmaking: Improving quality is a standard reference for researchers and professionals in the bread industry and all those involved in academic research on breadmaking science and practice.- With comprehensively updated and revised coverage, this second edition outlines the latest developments in breadmaking science and practice- Covers topics such as wheat chemistry, wheat starch structure, grain quality assessment, milling and wheat breeding- Discusses dough development and bread ingredients, with chapters on dough aeration and rheology

1

Introduction to breadmaking

S. Cauvain, BakeTran, UK

Abstract:

The nature of bread quality is discussed and the relevance of the various chapters that follow to improving bread quality introduced. The essential nature of gluten and its development in breadmaking is considered along with aspects of food safety and nutrition. The underpinning processes that contribute to current and future bread qualities are highlighted.

Key words

quality

food safety

nutrition

processing

1.1 Introduction

Mention the word ‘quality’ and on a good day my eyes normally glaze over as pictures of detailed and often meaningless ‘procedures’ apparently designed to ensure the quality of a process or a product spring to mind. On a bad day I might run screaming from the room. The big problem with most ‘quality systems’ is that they fail to take sufficient account of the ‘real’ purpose of the procedure or product concerned. This is especially the case in breadmaking where the perception of product quality is very personal. We all have our selection of criteria that classify bread as ‘good’ or ‘bad’, ‘correct’ or ‘wrong’ and while there are some common characteristics on which many of us would agree (for example, the bread should not be mouldy at the time of consumption) the final judgement of what is the right quality will always be highly personal. I am known for answering the question from bakers as to what is the ‘right’ quality along the lines of ‘Whatever product quality you can make consistently that brings customers back time after time, and which you can make money producing’.

In the final analysis if we define quality as being ‘fitness for purpose’ then for each of us the bread quality may be described as being the sum of those quality traits that confer the sensory pleasures associated with smell, taste and texture. In summary, when we taste and eat the product we experience pleasure. Our individual perception will then depend on the combination of those parameters that characterise the mix of product appearance, texture, smell and flavour which best suits each of us and have become part of our subconscious perception of bread quality. We must also recognise that our perception of quality will change with the passage of time and personal circumstances, not least our individual health.

While there are many factors which characterise the quality of bread products that can be easily defined and measured, e.g. loaf height and volume, there are many others which are ephemeral in nature and therefore more difficult to define, e.g. smell and flavour. In defining quality, the term ‘consistency’ is often used as frequently as fitness for purpose. Consistency is indeed a desirable quality trait with most products but for the highly individual perception of bread quality even this ‘simple’ quality trait is difficult to apply with absolute certainty. If you are a sandwich maker then you certainly want consistency of volume, shape and cell structure but in a craft bakery context, customers may still want to choose between light and dark crust coloured products. The variability in bread qualities sought by consumers demands that bakers be able to meet all of the quality requirements concerned. All in all, breadmaking requires a deep understanding of the many complex raw material and process interactions that collectively contribute to final product quality and it is the skills of bakers which ensure that the required qualities are delivered to consumers.

1.2 Wheat and its special properties

Almost every discussion of bread and its quality will start with a reference to the special nature of wheat, and given that wheat flour is the largest ingredient in dough and bread formulations, this is hardly surprising. In the contributions that follow, much will be made of the special properties of wheat flour proteins to form gluten after hydration and during mixing, whether that mixing is delivered mechanically or by hand. Dough mixing is the process that starts dough aeration as the gluten forms a network which traps and retains bubbles of air for inflation by carbon dioxide gas from yeast fermentation or in more ‘natural’ processes from lactic acid and other types of bacteria. It is because of the special properties of wheat proteins that much research has been devoted to them. Chapter 3 provides a comprehensive insight to the many different aspects of wheat chemistry and biochemistry and this theme is continued in Chapters 5, 6 and 4. Improvements in wheat quality to make it better suited to its end uses are considered in Chapters 9 and 10, along with opportunities for future development. The key role of gluten-forming proteins rightly receives considerable attention in several chapters but to address the balance, the role of wheat starch is considered in Chapter 6.

Fundamental to achieving a given bread quality is the ability to measure wheat quality and predict the likely breadmaking performance of any given wheat sample (Cauvain and Young, 2009). This has been the ‘holy grail’ for farmers, millers and bakers for centuries. Cereal science has developed many techniques and tools to help, but the complexity of those little wheat grains and the impact of farming practices on grain quality means that the goal still remains largely unattained. Much progress has been made and is considered in several of the chapters that follow. However, if you read on expecting to encounter a single test for making the perfect prediction you will be disappointed. It remains unlikely that there will be a single test (other than baking) that will predict bread quality with certainty. The many different types of bread and breadmaking processes, each requiring a degree of variation in the ‘quality’ predictors, reduce the likelihood of achieving a single quality test. For the moment we will have to content ourselves with using a range of analytical techniques and a number of these are addressed in the chapters of this book, which may help you decide which combination best suits your particular needs.

1.3 Converting wheat to flour

In order to make an aerated bread structure it is necessary to process the wheat grains into another, more suitable form. Over the centuries techniques have evolved that permit the separation of the white endosperm from the darker-coloured bran skins and germ. The progression towards greater availability of white flour has spawned the large number of bread products that we see in bakeries today. A number of factors have driven the move to white flours, not least the greater gluten forming potential of the wheat proteins in the starchy endosperm. As discussed in Chapter 8 the flour milling process has evolved into a sophisticated process but its efficiency and economic viability still depend on the quality of the raw material entering the flour mill. Because of this flour millers remain acutely aware of the need to assess wheat quality and link its qualities with the final product for which it is destined. Flour millers therefore continue to use a range of tests to assess both the reliability and consistency of their own operations (Cauvain and Young, 2009).

It is perhaps worth a comment on the subject of flour specifications. Too often the baker has difficulty in relating flour specifications to flour performance in bread baking. The key requirement is that the flour which bakers use should make the product that bakers (and their customers) require. The flour specification may well be the basis for confidence that the flour will deliver the required end product, however, it should be noted that since there is no definitive means of predicting the performance of a given flour in a given baking process, then the main purpose of measuring flour characteristics on a regular basis is to assess whether the flour meets the original specification. In other words the specification is about whether the flour is the same as delivered on previous occasions and as such is only an indication that it will make the end product required. Flour quality checks should only be seen as ‘ticking the required quality boxes’. It is essential that when bakers choose flours for production then they specify what they need: this is not always an easy task but the risks associated with inappropriate choices can be very costly in production terms.

1.4 Food safety and nutrition

Cereals and cereal-based products are amongst the safest of foods that we have available. However, growing and processing grain is not without its hazards. Some of the most deadly toxins are those which occur naturally. In cereals such unwanted materials may come in the form of mycotoxins. With the widespread transport and longer-term storage of cereal products, issues of food safety have become increasingly important and for these reasons the detection and control of mycotoxins materials are the subject of Chapter 25.

Bread and other fermented products have remained a staple food for thousands of years. In the past the key role for bread was the simple provision of energy, but in more recent years the role that wheat-based products play in delivering additional nutritional benefits has become more prominent. Such benefits include the provision of fibre and essential nutrients beyond the simple value of protein and carbohydrate. Wheat-based products have been and are still seen as potential vehicles for delivering addition nutritional value through fortification because of the significant contribution that wheat-based products make to many diets around the world. Fortification has commonly been practised using calcium, iron and some vitamins but to this list in recent times we should add folic acid. Food fortification is not without its critics and is not universally practised, nevertheless the ubiquitous nature of wheat-based products does offer a ready vehicle for delivering improved nutrition to many parts of the world.

Since nutritional properties are not homogeneously distributed throughout the wheat grain, separating the endosperm from the other components to yield white flour is not without its penalties. In those circumstances where nutrition is at a premium the fortification of flour- and wheat-based products has become a political and humanitarian issue. The role of fortification and the means by which it may be achieved are discussed in Chapter 27, and they provide an insight to another important aspect of bread quality.

The nutritional–quality link is also covered in Chapter 29 where the role of increasing fibre levels in bread is discussed. In many parts of the world previous approaches to breadmaking had become dominated by white flour-based products but now there is a greater use of higher extraction flours and combinations of wheat flours with other grains and seeds. The conversion of all wheat grains to flour has always been with us but the quality attributes of wholemeal or wholewheat bread have not had sufficient appeal for the mass market. In the UK when the technology developed for making wholemeal and similar breads as large and similar in softness to white breads sales rose from 2 to 20% of breads sold. In recent years there has been a small decrease in non-white bread production and consumption but levels remain higher than 25 years ago. The increase in sales was truly product quality-driven, since the fibre hypothesis had been around for quite some years with little impact on the dietary habits of the average UK consumer.

As special as wheat and wheat-based products may be there are some communities which cannot tolerate the proteins that are present in wheat and some other grains. The prevalence of coeliac disease and wheat intolerances are the subject of much new research and the need to develop suitable products is highlighted in Chapter 28.

1.5 Making bread

Breadmaking is a centuries-old traditional craft, practised in any country capable of growing or importing wheat. This has meant the evolution of a diverse range of breadmaking processes designed to achieve a wide range of bread products. There are a number of central themes that are common to all bread products and breadmaking processes. They are: the mixing of wheat flour, water, yeast and other functional ingredients and the expansion of the dough mass through the generation of carbon dioxide gas.

In Technology of Breadmaking (Cauvain and Young, 2002, 2007) it has been stated of no-time dough-making processes that ‘About 90% of final bread quality is decided by what bakers chose to do in the mixer’. This aspect of quality embraces the choice of raw materials and formulation as well as decisions on how to mix and develop the gluten structure in the dough. The relationship between mixing and dough development is still not fully understood. This theme is visited in many of the chapters in this book. It is well known t...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Contributor contact details
• Woodhead Publishing Series in Food Science, Technology and Nutrition
• Chapter 1: Introduction to breadmaking
• Chapter 2: Breadmaking: an overview
• Part I: Wheat and flour quality
• Part II: Dough development and particular bread ingredients
• Part III: Bread sensory quality, shelf life and safety
• Part IV: Particular bread products
• Index