
The book Dietary Egg: Nutritional and Commercial Facets has been written with the aim of addressing the need for a comprehensive resource on egg production and processing. It has been authored with the purpose of filling the gap in the market for a recent book that provides detailed information on this less commonly explored topic. The book scope is extensive, and it is intended for a diverse audience, including specialists, students, entrepreneurs, academicians, and research scientists. It covers a wide range of topics, from the structure of eggs to their processing and preservation.
The book provides a comprehensive overview of the current state of egg production and processing, as well as knowledge and technologies that can be used to improve egg products. It is expected to be a valuable resource for students, researchers, and academicians working in the egg sector. The title of the book is particularly fitting, as it emphasizes the scientific and technological advancements in the field of egg science throughout its content. This book is expected to provide a valuable resource for a variety of professionals working in the dynamic area of egg processing, layer management, quality control, and food technology, as well as students who will gain first-hand information on this subject.
This book Dietary Egg: Nutritional and Commercial Facets provides comprehensive coverage of the Science and Technology of egg for people working in the egg industry along with students and researchers to learn about rapidly booming egg industry. The book covers all areas of egg from initial egg formation to final processing. The goal of this book is to provide thorough information of egg industry. The coverage includes major egg production practices, handling, and nutritional composition of eggs, egg handling storage and preservation. Even though there are many books on this subject but there was long felt necessity to get all information at one place. To meet this demand this book is made concisely to meet such expectation.
1.1 Introduction Poultry is one of the fastest-growing areas of India’s agricultural industry, with an annual growth rate of around eight percent. Over a span of four decades, the chicken industry in India has seen a paradigm shift in structure and operation, transforming from a simple backyard occupation to a significant commercial agri-based enterprise. Constant efforts in upgrading, modifying, and using new technologies opened the path for the multiplication and diversification of poultry industries. The expansion is not just quantitative, but also qualitative, sophisticated, and productive. This transition has necessitated substantial expenditures and increases in breeding, hatching, raising, and processing. The rise of the poultry industry in India is also characterised by the expansion of chicken farms.
2.1 Introduction The biochemical environment for egg production and ovulation egg fertilisation is provided by the poultry oviduct. The chickens have two ovaries and an oviduct when they are hatched, but the growth of the right ovary and oviduct stops and regresses over time. The left ovary and oviduct are still functioning and help produce eggs. The oviduct is a long tubular structure that is divided into five functionally and histomorphologically distinct segments: the infundibulum, which is the site of fertilisation, the magnum, which produces egg white components, the isthmus, which forms the egg shell membranes, the shell gland or uterus, which produces the calcified eggshell, and the vagina (oviposition or egg laying).
3.1 Introduction Eggs are composed of three main parts; the eggshell with the eggshell membrane, the albumen or white, and the yolk. The yolk is surrounded by albumen, which in turn is enveloped by eggshell membranes and finally a hard eggshell. 3.2 Eggshell The eggshell is composed of a foamy layer of cuticle, a calcite or calcium carbonate layer, and two shell membranes. The ultrastructurally the eggshell includes shell membranes, mammillary zone, calcium reserve assembly, palisades, and cuticle, with 7,000 – 17,000 funnel shaped pore canals distributed unevenly on the shell surface for exchange for water and gases
4.1 Introduction The egg is made up of three primary components: the egg white, the egg yolk, and the egg shell. The calcite crystals of the shell are enmeshed in a protein and carbohydrate complex matrix. About 58% of the weight of an egg is made up of the viscous, colourless liquid termed egg white inside the shell. About 75% of the weight of an egg’s edible component is made up of water, although proteins and lipids make up the majority of its nutritional worth (Table 4.1). There are also trace quantities of minerals, often known as ash, and carbohydrates, which take the form of simple sugars including glucose, sucrose, fructose, lactose, maltose, and galactose.
5.1 Introduction The egg production in the country has increased from 78.48 billion in 2014-15 to 114.38 billion in 2019-20. India ranks 3rd in egg production in the world. Annual growth rate of egg production was 4.99 per cent during 2014-15, there after there has been a significant improvement in the egg production with 10.19 per cent growth registered in 2019-20 over the previous year. The per capita availability of egg was 86 per annum in 2019-20. Less than a generation ago the main supply of eggs was from small backyard unit. Processors, handlers, and distributors of eggs and egg products need an understanding of egg-production practices to cope more intelligently with problems of product quality and character.
6.1 Introduction The egg production in the country has increased from 78.48 billion in 2014-15 to 114.38 billion in 2019-20. India ranks 3rd in egg production in the world. Annual growth rate of egg production was 4.99 per cent during 2014-15, there after there has been a significant improvement in the egg production with 10.19 per cent growth registered in 2019-20 over the previous year. The per capita availability of egg was 86 per annum in 2019-20. Less than a generation ago the main supply of eggs was from small backyard unit. Processors, handlers, and distributors of eggs and egg products need an understanding of egg-production practices to cope more intelligently with problems of product quality and character
7.1 Introduction From a nutritional standpoint, eggs are particularly interesting since they include important fats, proteins, vitamins, minerals, and trace elements. They also provide a moderate calorie supply (about 140 kcal/100 g), have a wide range of culinary applications, and are relatively inexpensive. Indeed, it has been shown that eggs are the second-cheapest animal source for zinc and calcium and the lowest-cost source of proteins, vitamin A, iron, vitamin B12, riboflavin, and choline. Eggs include a wide variety of physiologically active ingredients in addition to offering babies and adults well-balanced nutritional needs. These elements are distributed throughout the many internal egg components. It must be noted that while eggshell membranes are edible, eggshell and its closely related eggshell membranes are often not ingested (Figure 7.1).
8.1 Introduction Egg is a perishable product having short shelf life. The table eggs are of highest quality when they are laid. Preservation of eggs should start from the point of production itself. The following practices are recommended as routine for the production of quality eggs on the farm. 1. Collection of eggs at least 3 times daily. 2. Using a clean receptacle with ventilated sides and bottom, preferably filler f lats.
9.1 Introduction Many cultures throughout the world see the egg as nature’s perfect meal. Many other kinds of animals lay eggs, yet the vast majority of people eat chicken eggs. There are a number of reasons why the quality of an egg matters today. Grading eggs is so essential. Quality, size, shape, weight, and other characteristics are all taken into account while sorting eggs for grading. To put it simply, food quality refers to the traits of a product that determine whether or not it is accepted by the target audience. Egg quality is based on both industry standards and consumer expectations. Considerations from the outside include egg shell composition, hue, form, and feel. Air cells, egg white, egg yolk, etc., are all examples of internal quality.
10.1 Introduction The primary purpose of egg packaging is to keep the egg safe from damage, such as cracking, while in transit. By limiting gas exchange via the shell and shell membrane, the egg package may help safeguard the egg’s internal quality. Once an egg has been deposited, it is immediately exposed to the conditions of the henhouse. In this environment, it is exposed to many different microorganisms. Almost often, there are no negative effects on health. However, there are microbes that can ruin eggs and others that can cause food poisoning. Salmonella bacteria are found in the digestive tract of all animals and can contaminate the poultry houses.
11.1 Introduction Egg contents may be contaminated via vertical or horizontal paths. In the former, bacteria may colonise the ovaries and/or oviduct, whereas in the latter, pollutants, such as faecal matter or dust, travel through the shell and colonise the membranes and yolk. The surface of a nest-fresh egg provides minimal protection against bacterial pollutants, resulting in the dominance of Gram-positive Micrococci in the shell microflora. Nonetheless, a variety of conditions have been demonstrated to either increase the survival of bacteria in the unfriendly environment of the egg’s shell surface or to impair the egg’s antimicrobial defence mechanism in other ways.
12.1 Introduction The eggs represent very good basis that can be enriched with useful and beneficial substances and become functional food, since certain beneficial substances which layers consume in their daily diets transfer relatively easily into their products. However, enrichment of poultry meat and eggs can have adverse consequences in regard to their quality. Functional food is interesting also from the economical aspect, because it opens for poultry producers the possibility to introduce new products into their product range. Of course, main assumption is that consumers of enriched products are willing to pay premium price for these products, which is by 15-20% higher than average product price. On a global basis, eggs are one of the most recognized and accepted foods by consumers.
13.1 Introduction Many changes have occurred in egg production and processing, as well as in the egg itself, over the last 40 years. All of these changes have contributed to the microbial challenges of the egg that we face today. In the past, production traits including egg size, feed conversion and egg output have received the majority of attention in genetic selection of laying hens. Microbial integrity hasn’t been given much attention. Until the 1990s, food safety concerns associated with shell eggs were not considered. Eggs were thought to be pathogen free until they were cracked.
14.1 Introduction Eggs are an essential food for humans due to the high nutritional quality and quantity that they contain. Eggs are one of the most consumed foods all over the world because of its nutritious profile, range of uses, and relatively inexpensive cost as a food source. Intakes of total lipids, cholesterol, and saturated fatty acids in human diets can be attributed, in part, to the consumption of animal products. Due to the high amounts of cholesterol (about 200-300 mg/100 g) and saturated fat (approximately 3 g/100 g), eggs have been considered to be contentious foods by several health organisations and nutritional experts.
15.1 Introduction In addition to serving as a means of reproduction, avian eggs are a staple meal in the diet of humans and include a natural balance of all the required components. However, eggs must overcome a few drawbacks in the current food market in order to compete for sales with an expanding number of other items. For instance, eggs are a delicate commodity that age-related quality reduction. Additionally, the intrinsic variability of the egg’s three primary parts—the shell, albumen, and yolk—does not meet the demands of contemporary customers for consistency. The successful sale of eggs depends on planned production techniques and effective quality control processes, both of which contribute to decrease this fluctuation.
16.1 Introduction Successful egg production is highly dependent on sanitation and decontamination, and producing clean eggs is the most major element of egg sanitation. Egg contents might become contaminated either vertically or horizontally. The ideal option for small farms can be to keep hatching eggs in a hygienic area and incubate them as soon as possible without sanitation but it’s not the same kind in case for commercial producers need to get a poultry veterinarian guidance on the proper egg handling and sanitation program depending on their needs. There are several preharvest techniques used to minimize egg contamination, including immunization, feed additives, home sanitation, bacteriophages, and biosecurity.
17.1 Introduction The plant layout needs a proper arrangement of each constituent area, along with their interrelationship. One of the most important considerations is the future expansion potential. The plant layout design should permit expansion readily and economically. One side of the building should be free of permanent installations such as compressors, septic tanks, toilets, drain fields, offices, and loading docks to permit the addition of building units without relocating these auxiliary facilities.
18.1 Introduction The egg industry has grown quickly in the last decade as people’s eating habits have become more aware of the importance of good and nutritious diets. Eggs are now widely accepted as a good source of high-quality protein. However, at the same time, the eggshell that pollutes the environment is discharged into the open. This eggshell waste can be used to make a variety of items, including pharmaceuticals and medicines. Additionally, this raw material is inexpensive and conveniently accessible. Eggshells are ranked as the fifteenth biggest environmental pollutant.
19.1 Introduction Quality has been defined as the properties of any given food that have an influence on the acceptance or rejection of this food by the consumer. Egg quality is a general term which refers to several aspects of both internal and external quality. Internal egg quality involves functional, aesthetic and microbiological properties of the egg yolk and albumen. The proportions of components for fresh egg are 32% yolk, 58% albumen and 10% shell. The quality of an egg is at its best when the egg is laid. There is no known method by which this quality can be improved subsequently.
21.1 Introduction The egg industry has grown quickly in the last decade as people’s eating habits have become more aware of the importance of good and nutritious diets. Eggs are now widely accepted as a good source of high-quality protein. Increased demand in consumer choice has resulted in a wide variety of egg selection available in the retail market. Eggs of high quality are needed to sustain niche markets for specialty and designer eggs–seeking consumers. Egg quality defines those characteristics of an egg that affect consumer acceptability and preference. The parameters for egg grading include shell cleanliness, strength, texture, and shape; the relative viscosity of the albumen; and the shape and firmness of the yolk.
22.1 What is Livestock Product Marketing? Livestock Products Marketing is the change of ownership of livestock derived food products. It links the livestock production and food consumption. There are three aspects of livestock market transactions: 1. Spatial – transactions occur across space 2. Temporal – transactions occur across time 3. Form – transactions occur in a certain form
23.1 Introduction Eggs are nutrient dense superfoods, naturally occurring vitamin pills. They contain a complete source of protein with all essential aminoacids and naturally occurring vitamin D. The adverse publicity of high cholesterol content in the egg limit their intake. Nowadays consumers need the products free from drugs/ pesticides and contain special health promoting substances. To reap the growing demand of health conscious consumers and to make available of their requirements, designer eggs are made. Designer eggs are those eggs their composition differ from the standard eggs by changing the feed of the hen.
24.1 Introduction Egg Products have gained great acceptance all over the world to-day as they offer advantage in labour saving and time in preparations, space saving and consistency in quality. There is also an an increase in consumer demand for a variety of preparations to suit their taste and purse. Today’s commercial bakeries, food processing plants and institutions use tremendous quantities of liquid bulk eggs, egg solids (dried egg) and frozen egg products for preparation of several convenient foods.
25.1 Introduction There has been a recent increase in the consumption of organic food, particularly in developed countries. Consumer awareness is growing in terms of organic food products in recent years as almost all the food ingredients are grown under intense production systems which utilize lot of chemicals and pesticides to control the pests and diseases. Organic farming can be defined as an approach to agriculture where the aim is to create integrated, humane, environmentally and economically sustainable agricultural production systems producing acceptable levels of crop, livestock and human nutrition, protection from pests and diseases, and an appropriate return to the human and other resources employed.
26.1 Introduction The egg’s primary non-food purpose is to help the species reproduce. The quantity of eggs required for the hatching of chicks has increased significantly due to the substantial rise in meat consumption. The USDA has made a list of a few other non-food use for eggs. Inedible eggs are often used as animal feed and plant fertilizers. Eggs are also fed to show animals, such as dogs and horses, to improve the glossy sheen of the fur coat. Industrial egg albumen is used in finishing several types of leather, notably coloured stock, and glazed. production of vaccines in chick embryos is one of the key uses of eggs, as per various researchers.
27.1 Introduction Eggs containing nutrients that play fundamental roles beyond basic nutrition in consumers and their promotion as functional foods should be considered. Eggs rich in protein and offer a moderate calorie source (about 150 kcal/100 g), rich in vitamins and minerals and also great culinary versatility and low economic cost, which make eggs within reach to most of the population. Eggs are also relatively rich in fat-soluble compounds and can, therefore, be a nutritious inclusion in the diet for people of all ages and at different stages of life. In particular, eggs may play a particularly useful role in the diets of those at risk of low-nutrient intakes such as the elderly, pregnant women and children.
28.1 Introduction The majority of eggs produced in the world are sold in-shell for consumers to utilize in the home in traditional ways or for baking. Traditionally, surplus eggs not required for the shell egg market (normally the smaller sizes) and downgraded eggs were turned into egg products. Today, farmers have specific contracts to produce eggs for further processing, and any egg that is damaged cannot be used for this purpose. There are essentially three types of egg products, liquid, dried, and frozen, with small markets for peeled, hard-boiled, and hard-boiled pickled eggs.
A Addled egg 128 Ageing egg 127 Air cell depth 57, 146 Albumen index 143, 144 Alpha linolenic acid (ALA) 79 Aluminium Sheet Roofing 28 Ammonification 181 Animal Protein Factor 24 Anticollagenase 21 Antimicrobial defence mechanism 71 Antinutritional Factors 45 Anti-oxidants 80, 81, 82 Antiseptic 52 Apple egg drink 169 Avian beta-defensins 10
