Egg Science and Technology

William J Stadelman, Debbie Newkirk, Lynne Newby

• Publisher: CRC Press
• Year: 2017
• Print ISBN: 9781560228547
• eBook ISBN: 9781351453707
• Topic: Biological Sciences
• Subtopic: Biology
• Index: Biological Sciences

Here is the complete source of information on egg handling, processing, and utilization. Egg Science and Technology, Fourth Edition covers all aspects of grading, packaging, and merchandising of shell eggs. Full of the information necessary to stay current in the field, Egg Science and Technology remains the essential reference for everyone involved in the egg industry. In this updated guide, experts in the field review the egg industry and examine egg production practices, quality identification and control, egg and egg product chemistry, and specialized processes such as freezing, pasteurization, desugarization, and dehydration. This updated edition explores new and recent trends in the industry and new material on the microbiology of shell eggs, and it presents a brand-new chapter on value-added products. Readers can seek out the most current information available in all areas of egg handling and discover totally new material relative to fractionation of egg components for high value, nonfood uses.Contributing authors to Egg Science and Technology present chapters that cover myriad topics, ranging from egg production practices to nonfood uses of eggs. Some of these specific subjects include:

• handling shell eggs to maintain quality at a level for customer satisfaction
  
• trouble shooting problems during handling
  
• chemistry of the egg, emphasizing nutritional value and potential nonfood uses
  
• merchandising shell eggs to maximize sales in refrigerated dairy sales cases
  
• conversion of shell eggs to liquid, frozen, and dried products
  
• value added products and opportunities for merchandising egg products as consumers look for greater convenience

Egg Science and Technology is a must-have reference for agricultural libraries. It is also an excellent text for upper-level undergraduate and graduate courses in food science, animal science, and poultry departments and is an ideal guide for professionals in related food industries, regulatory agencies, and research groups.

Chapter 1

The Egg Industry

W. J. Stadelman

The egg industry of the world is primarily based on chicken (Gallus domesticas) eggs. With the development of a more mobile world population the introduction of duck eggs with southeastern Asian nationals are becoming more of a factor. In some African countries guinea eggs are commonly seen in the marketplace, especially in the spring of each year. Coturnix quail eggs are being marketed in Japan and some Western countries and are generally sold as hard-cooked eggs packaged in jars in a preservative brine solution. However, throughout this text all references to eggs will mean chicken eggs, unless specifically identified otherwise.

PRODUCTION OF SHELL EGGS

Eggs are one of the few foods that are used throughout the world; thus the egg industry is an important segment of the world food industry. Eggs have been an important part of the human diet since the dawn of recorded history. In modern times eggs have been an important commodity in international trade. The principal egg-producing countries of the world are listed in Table 1.1 with an indication of changes in production totals during the last 40 years. Production in 1950 showed the effects of World War II especially in Japan, the Netherlands, United Kingdom, and Germany. Production of eggs in China, South Korea, and Taiwan was not reported prior to the 1990 values (USDA, 1991).

The continuous expansion of the USSR egg production from 1960 through 1990 was the greatest in total volume. There was likely a similar expansion in China but long-term records to verify this are not available. Production in China increased by over 40,000 million eggs from 1987 to 1990, the only times data were available. Japanese production has also expanded rapidly. Although the countries in the North TeiKperate Zone are the primary producers, there is also substantial egg production in Southern Hemisphere temperate areas. The egg industry of many developing countries is expanding rapidly to help meet their protein needs, but limited feed supplies and the low poduction of native chickens hamper pogress. When high production strains are introduced, the stress conditions of disease and poor management frequently lead to failure. Cross breeding of local disease resistant strains with imported high production strains has helped to resolve this problem. As many of the developing nations are located in the tropics the adverse effects of high temperatures (see Chapter 2) must be overcome.

TABLE 1.1. Countries of the world with egg production over four billion eggs in 1990.

¹ Not available

² West Germany

³ East and West Germany

⁴ Includes all reporting countnes

Source: USDA (1952, 1962, 1972,1982, 1991).

As indicated in Table 1.1, the major egg-producing countries of the world have changed in ranking in the last ten years. With production data from China, Taiwan, and South Korea, total reported world production expanded by about 30% over the 20 years. Because of political changes in Eastern Europe since 1990 it is possible that continued expansion there will be slowed because of a lack of feed grains.

Within the United States the egg industry was historically located in the north central states. More recently the West Coast and southeastern states have become major production areas. The changes from 1950 through 1990 are indicated in Table 1.2 for states and regions. The declining hen population and the increased average hen production are also indicated.

The production units are also changing rapidly. Before World War II egg production in the Midwest was largely a farm-flock business. Most of the eggs produced were from hens in flocks of less than 400. In 1949, 2,422,000 farms reported selling eggs. By 1964 this number had decreased to 527,000, and in 1974, only 198,577 farms reported selling eggs. Of this reduced number in 1974 almost 73% reported flocks of less than 100 hens. These 144,911 farms accounted for only 0.16% of all layers kept in the United States. On the other end of farm size, 354 farms or 0.18% of all poultry farms accounted for over 30% of all laying hens in the 1974 census. Another indication of commercialization in the egg industry is the report that in 1978, 34 firms had 69,650,000 layers, or about 25% of the hen population. In 1981,47 egg-production companies owned 96,389,000 hens or 37.1% of the laying hens in the U.S. Many of these companies had several farms; the largest had farms in 13 states.

In 1990 there were about 940 owners each with over 30,000 layers. The largest egg-producing organization in 1991 had over 15 million layers distributed at a number of locations.

The trend to commercial size egg-production flocks is not limited to the United States; similar changes are occurring in all parts of the world. Even the flocks of 100,000 hens or more are found in many countries. One of the reasons for the increases in flock size is the development of mechanical equipment to aid the caretaker in watering, feeding, ventilation, egg handling, and litter management. On fully mechanized farms a single caretaker can manage over 100,000 laying hens. Assistance is needed only in egg packaging and when hens are sold or pullets are put into the facility. Such operations should be an all-in, all-out situation so that only dead or ill birds are removed, and no replacements are added.

TABLE 1.2. Egg production by states and regions of the United States.

Source: USDA (1952, 1962, 1972, 1982, 1991).

EGG-PRODUCTS INDUSTRY

The egg industry is divided into areas of specialization, as is true of most production industries. A relatively few poultry breeders supply the hatching eggs for the commercial laying flocks. The number of hatcheries operating today is a small fraction of those in business only 20 years ago. Similarly, there are specialists in feed formulation and manufacture, replacement pullet rearing, equipment and house construction, laying flock management, and egg marketing. Eggs are usually marketed as shell eggs, although an ever-increasing percentage of the total production is sold to the consumer in the form of egg products or formulated foods. Over 25% of all eggs sold in 1993 were in product form.

The egg-products segment of the egg industry in the United States dates from about 1900. The first product was frozen whole eggs, followed closely by separated whites and yolks (frozen). With improvements in technol...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Table of Contents
• About the Editors
• Contributors
• Preface
• Chapter 1. The Egg Industry
• Chapter 2. Egg-Production Practices
• Chapter 3. Quality Identification of Shell Eggs
• Chapter 4. The Preservation of Quality in Shell Eggs
• Chapter 5. The Microbiology of Eggs
• Chapter 6. The Chemistry of Eggs and Egg Products
• Chapter 7. The Nutritive Value of the Egg
• Chapter 8. Merchandising Eggs in Supermarkets
• Chapter 9. Egg-Products Industry
• Chapter 10. Egg Breaking
• Chapter 11. Freezing Egg Products
• Chapter 12. Egg-Product Pasteurization
• Chapter 13. Desugarization of Egg Products
• Chapter 14. Egg Dehydration
• Chapter 15. Quality Assurance
• Chapter 16. Functional Properties of Eggs in Foods
• Chapter 17. Hard-Cooked Eggs
• Chapter 18. Composition Modification of Eggs
• Chapter 19. Development of Value-Added Products
• Chapter 20. Nonfood Uses of Eggs
• Chapter 21. Egg Product, Process, and Equipment Patents (U.S.)
• Chapter 22. Selected Bibliography of Doctoral Dissertations on Eggs and Egg Products
• Appendix
• Index