Cereal Grains (eBook)

Assessing and Managing Quality

Colin Wrigley (Herausgeber)

eBook Download: PDF | EPUB

2010 | 1. Auflage
552 Seiten
Elsevier Science (Verlag)
978-1-84569-952-9 (ISBN)

Infos

Cereal grains are essential to our dietary needs, as well as for animal feeding and for industrial processing. Consumer needs can only be met by managing quality at all stages of the grain chain. Quality evaluation is also needed at each step for effective management. Cereal grains: assessing and managing quality provides a convenient and comprehensive overview of academic research and industry best practice in these areas.After an initial chapter introducing the themes of the book, further chapters in Part one review cereal grain morphology and composition and the diversity of uses of cereal grains. Chapters in Part two convey the characteristics and quality requirements of particular cereals, including wheat, rye, corn and rice. The use of analytical methods at different stages of the value-addition chain is the subject of Part three. The final section in the book reviews factors affecting grain quality such as breeding, storage and grain processing, and also possible future developments.With its expert team of editors and authors, Cereal grains: assessing and managing quality is a valuable reference for all those involved in the production and processing of cereal grains worldwide. - Reviews cereal grain morphology and composition and the diversity of the different uses of cereal grains - Examines the use of analytical methods at different stages of the value-addition chain - Reviews the factors affecting grain quality such as breeding, storage and grain processing, as well as possible future developments

Textauszug

1

An introduction to the cereal grains: major providers for mankind’s food needs

C.W. Wrigley,     formerly CSIRO Food and Nutritional Sciences, Australia

Abstract:

Cereal grains are essential to our dietary needs, as well as for animal feeding and for industrial processing. The cereal species of agricultural significance are wheat, triticale, rye, barley, oats, maize, rice, sorghum and the millets, all members of the grass family. The grain industry can only meet consumer needs by managing grain quality at all stages of the grain chain, from breeding to production, harvesting, storage and finally processing into foods and animal feed. Assessment of grain quality is needed at all stages for effective management. The many analytical methods available need to be adapted to the specific needs at each stage of the value-addition chain.

Key words

value-addition chain

taxonomy

quality-assessment methods

consumer preferences

climate change

1.1 Introduction

The cereal grains are a major source of our dietary energy and protein requirements. They are also needed for animal feeding and industrial processing. The three major cereal species (wheat, maize and rice, Table 1.1) represent nearly 90% of cereal grain production; over 600 million tonnes of each is produced annually (Wood and Johnson, 2003; Champagne, 2004; Khan and Shewry, 2009). The other cereal grains of economic significance are triticale, rye, barley, oats, sorghum and the millets (Table 1.1). The range of cereal species is narrower than for the dicot grains, which are mainly oilseeds and legumes. On the other hand, the volume of production of the cereals is much greater than the production of the dicot grains.

Table 1.1

The major monocotyledonous (cereal) species listed in approximate order of economic significance

⁎World production and international trade (in millions of tonnes)

Source: FAOSTAT data, November, 2009 (www.fao.org)

The term ‘quality’ has different significance, depending on the stage being considered along the ‘grain chain’ – the continuum from breeding, through growing and management of the crop, to harvesting, segregation, storage and transport, to processing and final consumption.

The assessment of grain quality is essential to effective management of grain production and processing. Analysis of grain quality provides critical knowledge about the defects and advantages of the grain involved, thereby assisting those concerned along the value-addition chain on how best to manage processing for the financial benefit of the specific stage of the overall process (Atwell, 2001; Dixon, 2007).

Effective management of grain quality relies on analytical information along the consumption chain, providing a sound basis for assuring customer satisfaction. The ‘customer’ at any stage may be the next step along the grain chain, but the ultimate customer is the consumer. The degree of satisfaction is obviously related very closely to the price that will be paid at each stage of the value-added chain.

1.2 Grains and people

1.2.1 Grains in our diet

The cereal grains are produced by plants of the grass family (Poaceae or Gramineae). The species of agricultural significance are wheat, triticale, rye, barley, oats, maize, rice, sorghum and the millets. These are the grains described in this book. They are listed in approximate order of production volume in Table 1.1. Most important are wheat, rice and maize (corn).

The cereal group of plants has been very successful in contributing to mankind’s food needs. The success is indicated by the cultivation of many trillions of cereal plants worldwide (probably over 1012), resulting in an annual harvest totalling over 2.2 billion tonnes of cereal grain each year.

This level of production equates approximately to one kilogram of grain per person per day for the world’s population. However, world hunger does not reflect this statistic, because of the vast distances between the major production regions and the areas of human need, and because of the considerable amounts of grain used for industrial processing and animal feeding.

An assortment of cereal grains is illustrated in Fig. 1.1. The word ‘grain’ relates to the use of this part of the grass plant by mankind. In contrast, the word ‘seed’ relates to the plant’s means of producing another plant, thereby perpetuating the species. The words ‘kernel’ and ‘caryopsis’ are botanical terms for the grain. ‘Kernel’ is a relatively general term. The ‘caryopsis’ is defined as ‘a one-seeded indehiscent fruit in which the pericarp is fused with a seedcoat’. The grains of cereal grasses represent an entire fruit, and the term ‘caryopsis’ is generally limited to the cereal grains (as distinct from the grains of various dicot species).

Fig. 1.1 Various grains from cereal species.

The cereal grains share one central attribute that accounts for their success both in perpetuating themselves and in serving the needs of mankind; that characteristic is their ability to remain intact as a store of nutrients for long periods of time. For the seed, this period extends from the time that the mature plant sheds its dry seed until the ‘rainy day’, when the seed encounters moisture, triggering the processes of germination, sprouting and plant growth; in this way, the cycle of plant-seed reproduction goes on. The waiting period of the apparently dead seed may be long or short, depending on the timing of the ‘rainy day’. Safe storage of the seed’s nutrients throughout this waiting period is essential to the plant’s survival, irrespective of the conditions that may occur before the right combination of moisture and temperature arrives to initiate the germination response.

The ability of seed-bearing plants to preserve these stores of nutrients for long periods was the major reason for our ancient ancestors’ interest in the cereals as a food source. The harvested grain could be stored ready for the metaphorical ‘rainy day’, such as winter time, when other food sources were not available. In the same way, the storability of grains makes them an essential food source for us today.

1.2.2 Grains in our culture

Because the storability of grains helped ancient man to survive the ‘rainy day’ periods of his existence, the cereal grains were a major catalyst in transforming Homo sapiens from a hunter-gatherer into an agriculturalist, permitting ancient people to remain in one place, harvesting intentionally sown grain. As a result, fixed dwelling places were established near cereal crops, using the stored grain as a reliable source of food for family and feed for animals. This agricultural existence thus laid the foundations of a civilisation that could find spare time for the building of permanent dwellings, for cultural activities and for specialisation of occupation.

Grains have been recognised as an important food source since pre-history. The ongoing propagation and improvement of seed-bearing plants were important phases in the development of mankind. The selection of plant species that best suited our food needs commenced from those times. These activities continued on to the selection of genotypes with superior attributes, such as improved grain size, disease resistance and processing quality.

1.2.3 Grains in our language and festivities

Our intimate and long-lasting relationships with the cereal grains, with wheat especially and with grain-based foods, are indicated by the many ways in which they enter in our culture and vocabulary, becoming symbols of social interaction. As examples, ‘Give us this day our daily bread’, ‘Man shall not live by bread alone’, and ‘Cast thy bread upon the waters’ are everyday expressions in English derived from the Bible. There are equivalent expressions in other languages, cultures and religions.

Centuries ago, celebration of the grain harvest in Western Europe was justification for celebration and thanksgiving by farmers and villagers. This tradition was carried by the settlers in North America, leading to the traditional Thanksgiving Day celebrations of the USA and Canada.

In Eastern Europe, the completion of the grain harvest is a great occasion for celebration, known as ‘dozynki’ in Poland. Traditionally, villagers donned colourful folk costumes, sang and played instruments for the lord and lady of the manor, presenting wreaths made of corn, wheat stalks and flowers, together with bread baked from the freshly harvested wheat. Figure 1.2 illustrates how these traditions are perpetuated even today. Year round, these cultures continue to show reverence to cereal-based foods, for example by the presentation of a loaf of bread to an honoured...

Produkt-Details

• Erscheint lt. Verlag: 20.5.2010
• Sprache: englisch
• Themenwelt: Technik ► Lebensmitteltechnologie
• ISBN-10: 1-84569-952-1 / 1845699521
• ISBN-13: 978-1-84569-952-9 / 9781845699529