Quarter 1 Lesson 2 "Nutritional value and Components of eggs"

Eggs are important source of protein, essential vitamins and minerals, and can make a significant contribution to a healthy diet. Nutritional requirements can vary considerably between men, women and children, and can also vary in individual from time to time.

Here is a video all about it!

Energy Value of eggs 

*A medium egg has an energy value of 78 calories 

Protein 

Eggs are excellent source of protein. Egg protein is high of biological value as it contains all the essential amino acids needed by the human body. 12.5% of the weight of an egg is protein and it is found in both the yolk and the albumen. The egg white or albumen source you with quality protein, and those who require more protein can easily meet the requirement through other food items like lean meats. 

Vitamins 

Egg contains most of the recognized vitamins with the exception of vitamin C. The egg is a good source of all the B vitamins, plus the fat-soluble vitamin A. It also provides useful amounts of vitamin D, as well as some vitamin E. 

Minerals

Egg contains most of the minerals that human body requires for health. Eggs are an excellent source of iodine, required to make the thyroid hormone and phosphorus required for bone health. The egg provides significant amount of zinc that is important for wound healing, growth and fighting infection. Eggs also contain significant amounts of iron, the vital ingredient of red blood cells. 

Carbohydrate and dietary fiber 

Eggs contain only traces of carbohydrate and no dietary fiber. Eggs are packed with nutrients that boost brain and eye health and contain almost zero carbs!

Fat

An egg has 11.2% fat on its content. The fat of an egg is found almost entirely in the yolk. 

Cholesterol and Lecithin 

Cholesterol is the fat like substances and are essential to the structure and function of all cells in the body. Cholesterol helps to maintain the flexibility of all cell membrane. Lecithin is involved in general lipid transportation in the blood and in the metabolism of cholesterol.

Egg Structure

Eggs also has its parts, and consists of primarily a yolk, a white, and a shell. Here is a picture of the structure of an egg. 

Shell 

The outer layer of the egg which is the shell is made almost entirely out of calcium and has 8.000 tiny pores! The shell is the egg's first line of defense against bacterial contamination. The shell is a semipermeable membrane which means that the air and moisture can pass through its pores. The shell also has a thin outermost coating called the bloom or cuticle that helps keep out bacteria and dust. 

Air Cell 

Air cell is an air or empty space between the white and shell. Space forms when the contents of the egg cool and contract after the egg is laid. The air cell usually rests between the outer and inner membrane. It accounts for the crater you often see at the end of a hard-boiled egg. The air cell grows larger as an egg ages. 

Inner and Outer membrane 

These two membranes are just inside the shell surrounding the albumen. The two membranes provide an efficient defense against bacterial invasion. The outer membrane sticks to the egg shell while the inner membrane sticks to the albumen. If you give these layers a tug, you'll find they're surprisingly strong! They're made partly of keratin, a protein that's also in human hair. 

Yolk 

The yellow part of the egg or the yolk is a major source of vitamins and all of the fat and cholesterol. These include iron, vitamin A, vitamin D, phosphorus, calcium, thiamine, and riboflavin. The yolk is also a source of lecithin which is an effective emulsifier. The yolk also  contains less water than the albumen. It contains the food that will nourish the embryo as it grows. Yolk color ranges from just a hint of yellow to a magnificent deep orange according to the feed and breed of the hen. 

Chalazae 

These are twisted in opposite directions and serve to keep the yolk centered. The more prominent the chalazae, the fresher the egg. Like little anchors, they attach the yolk's casing to the membrane lining the eggshell. 

Albumen 

Albumen is the white part of an egg. It is the clear liquid contained within an egg or the part that surrounds the yolk. The albumen comes from albus which is the Latin word for white. Four alternating layers of thick and thin albumen contain approximately 40 different proteins, the main components of the egg white in addition to water.

Germinal Disk 

Germinal disk also called as blastodisc. It is a small circular spot on the surface of the yolk. The germinal disk is where the female's genetic material is found. 

Vitelline Membrane 

The vitelline membrane or vitelline envelope is a structure surrounding the outer surface of the yolk. It is the clear casing that encloses the yolk. 

Lesson 2

LEARNINGS : "I have learned the benefits of eating an egg and disregarded the stereo types it has. I learned the parts of an egg, its functions and how it works. I don't really eat eggs that much, but now that I know that it has a lot of benefits and that your eye sight will improve, I decided to eat a lot and if possible, everyday!" 

REFLECTIONS : This is important in my daily life because at first, I used to brush of eggs because based on what I hear about it. But now that I know that it has a lot of health values and nutrition, my thoughts about it completely changed! I started to eat more, and I believe that it will improve my health.