Wheat Flour

William A Atwell, Sean Finnie

• Publisher: Woodhead Publishing and AACC International Press
• Year: 2016
• ISBN:
  9780128123669
• Edition: 2
• Topic: Technology & Engineering
• Subtopic: Food Science
• Index: Technology & Engineering

Wheat Flour

Chapter 1

Wheat

In This Chapter

• Historical Perspective
• Wheat Types
• Wheat Breeding
• Growth Regions
• Wheat Consumption and General Uses
• Kernel Structure
• Germination and Growth
• Wheat Production Problems
• World Wheat Production and Marketing
• Logistics
• Wheat Standards
• Wheat Storage
• Factors Important to the Wheat Producer

A wheat seed warms, and moisture begins to penetrate its outer layers. The metabolic processes fostering growth are initiated; a shoot emerges, as does a root, and the seed becomes a fledgling wheat plant. If conditions are favorable, the plant continues to grow, resembling its close cousins, the common grasses found in lawns. The plant continues to grow and, eventually, inside the stem, a head of wheat begins to develop. The stem swells, and then the head emerges. It flowers, initiating the development of new seeds within the head, which ripen from a soft “milky” consistency to kernels that eventually resemble the seed that initiated this entire growth cycle. As the wheat ripens, the plant turns from green to amber and loses moisture.

It is now time to harvest the new wheat kernels by mechanically separating them from the rest of the plant. Perhaps the wheat will be transported to elevators, stored, and transported to larger elevators before the wheat is tempered and milled into flour, or perhaps the kernels will be milled locally. Regardless of where it is milled, this “new crop” flour will eventually be used to produce a seemingly endless variety of wheat-based products.

As the major ingredient in such products, flour exerts a major effect on their quality. To be able to effectively use flour to make high-quality products without encountering processing or end-product quality problems requires a thorough working knowledge of all aspects of wheat and flour. It is the objective of this handbook to be a broad-based resource to aid the reader in acquiring this knowledge.

Historical Perspective

Clearly, wheat was one of the earliest and most widely grown agricultural crops cultivated by humans. It is generally accepted that wheat originated in the Tigris and Euphrates River Valley and that the cultivation of wheat as a food crop probably began between 10,000 and 8000 b.c.e Egyptian tombs 5,000 years old have been unearthed that contain hieroglyphics depicting the harvesting and processing of wheat. Chinese records of wheat date back to 2700 b.c.e. The hardiness of wheat and the variety of food forms that it can take have made it a truly universal part of the human diet.

Wheat Types

The first type of wheat cultivated was einkorn (Triticum monococcum), a diploid wheat containing seven chromosome pairs. Later a 28-chromosome tetraploid wheat known as emmer (T. dicoccum) evolved and was cultivated extensively in the Middle East. Emmer and einkorn are still cultivated and are now referred to as ancient grains. Durum wheat, which is used today to make pasta, is also tetraploid. Common wheat, which is used to make the wide variety of dough and batter-based products today, is hexaploid, having three pairs of each of the seven basic chromosomes.

Diploid—Describing an organism with two sets of chromosomes. An early wheat known as einkorn was diploid.

Chromosome—A body composed of DNA and carrying part of the genetic code for the organism, i.e., the wheat plant. There are seven distinctly different chromosomes in wheat.

Tetraploid—Describing an organism with four sets of chromosomes. Durum wheat is tetraploid.

Hexaploid—Describing an organism with three sets of chromosomes. Most common wheat is hexaploid.

With respect to biological classification, three species of wheat are most commonly grown today. The first, T. aestivum, forms the classes hard red winter, hard red spring, soft red winter, hard white, and soft white. T. compactum includes the club wheats. The third species is T. durum, which includes the durum and red durum wheat classes.

Species—A biological classification below genus and above variety. Wheat varieties from three species of wheat are commonly grown.

Class—A type of wheat usually designated by hardness, color, and growing season. Hard red spring wheat is a class of wheat that is commonly used to produce bread. Durum is a class of wheat used t...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• About the AACC International Handbook Series
• Preface
• Chapter 1: Wheat
• Chapter 2: Milling
• Chapter 3: Composition of Commercial Flour
• Chapter 4: Wheat Nutrition
• Chapter 5: Wheat and Flour Testing
• Chapter 6: Specifying “Quality” Flour
• Chapter 7: Products from Hard Wheat Flour
• Chapter 8: Products from Soft Wheat Flour
• Chapter 9: Pasta, Noodle, and Breakfast Cereal Products
• Useful Websites
• Glossary
• Index