eChapters

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.

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.

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.

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.

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.

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.

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).

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

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.

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.

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

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).

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.

Classification of Living Organisms

The classification of living organisms has passed through several changes and has reached the present stage with the gradual assimilation of more and more knowledge about them. The classification is mainly based on the morphology, anatomy, life style, habits, habitats, metamorphosis and such other characteristics. Though the concept of classification of living organisms was perhaps started by Aristotle between 384 - 322 BC, it was the Swedish Scientist Carl Linnaeus (1788), who presented the classification, which was acceptable to most of the Taxonomists. He propounded the binomial nomenclature of naming each and every organism of animal and plant origin with a genetic and species name. In his classification he was consistent in using Latin names for all the organisms.

Insects generally reproduce by laying eggs or ‘ova’. The initiation of growth inside an egg, which in most cases is preceded by fertilization, leads to a long series of changes, finally attaining the adult stage and in due course to sexual maturity and finally to reproduction of a new generation. This chain of events from the egg stage to adult constitutes the ‘life history’ or ‘life cycle’ of an insect.

Similar to animals of the higher order, insects also possess all important internal systems of organs necessary for the proper performance of the various vital functions. The most important of the systems are the alimentary or digestive system, the circulatory system, the respiratory system, the reproductive system and the excretory system. The fundamental arrangement of the various organs is more or less similar in all insects and does not exhibit much remarkable variations as seen in the external morphological features. The dorsal blood vessel or heart runs along the median line immediately below the dorsal wall. The digestive system including the alimentary canal and its appendages lie in the middle, below the heart. The nervous chain lies below the alimentary canal and immediately above the ventral wall.

The insect body is made up of multicellular tissues. The body is bilaterally symmetrical and is covered by a hard, chitinous exoskeleton. The chitin at the junction of the segments is thinner and pliable and hence insects can bend their bodies. The exoskeleton is made up of several layers of non-living cells produced from the epidermis. Because of the hard chitin us exoskeleton of the body, the growth of the insect is affected beyond a certain extent. So, to facilitate further growth,, this exoskeleton is cast off a few times and this is known as ‘molting’. The number of moultings in a particular species is more or less constant.

General Aspects About Insects

‘Insects’ are almost ubiquitous. They are found all over the world, in the icy regions of the poles, deserts, forests, mountain peaks, oceans and even in oil wells. They can adopt themselves to any climatic conditions and can live in any habitat where food is available. Insects are mostly small, air-breathing organisms of the animal world. Most of the insects live freely in nature. Many species are wild and harmless to human beings. Many are beneficial because of their role in the ecosystem. Some are a part of the food chains of wild creatures, while others through predation and parasitism hold in check many other species of insects. Insects also play a vital role in pollination. Relatively only a few species are harmful to man and are his chief competitor on earth.

Government of Andhra Pradesh has identified Horticulture sector as one of the growth engine with a focus to increase the production, productivity and quality all horticultural crops coupled with value chain development and marketing linkages for better price realization. Total area under horticultural crops is 17.95 lakh ha with a production of ` 314.78 lakh tonnes. Horticulture sector has recorded 10.17 % growth over previous year and contributing ` 49,189 crores during 2020-21 to GVA of Andhra Pradesh (DH, Govt. of Andhra Pradesh, 2021).

Plants have the ability to synthesize a wide variety of chemical compounds that are used to perform important biological functions, and to defend against attack from predators such as insects, fungi and herbivorous mammals. Many of these phyto chemicals have beneficial effects on long-term health when consumed by humans, and can be used to effectively treat human diseases. At least 12,000 such compounds have been isolated so far; a number estimated to be less than 10% of the total (Tapsell et al., 2006; Lai and Roy, 2004). These phyto-chemicals are divided into: (1) primary metabolites such as sugars and fats, which are found in all plants; and (2) secondary metabolites (SM) – compounds which are found in a smaller range of plants, serving a more specific function (Meskin, 2002). For example, some secondary metabolites are toxins used to deter predation and others are pheromones used to attract insects for pollination.