Raw Egg Yolk

Raw Egg Yolk: Exploring the Science Behind Its Journey from Farm to Plate

We’ve all taken a bite of an egg yolk before. Whether we’re downing breakfast scrambles, indulging in creamy deviled egg recipes, or using raw egg yolks for baking, the yellow center of a chicken egg is instantly recognizable. But what actually goes into making a raw egg yolk and ensuring that it reaches our dinner plate? From the moment it’s created to when we add it as the finishing touch to a delicious meal, tracing a raw egg yolk’s journey is a fascinating exploration of science and biology.

In order to understand the process of raw egg yolk creation, we must first discuss the anatomy of a chicken egg. Chicken eggs are composed of an inner egg white (or albumen) layer and an outer eggshell, both of which are surrounded by a membrane located between the egg white and the shell called the albumen sac. The majority of an egg’s contents are located in the egg yolk, or the yellow center. According to the USDA, the average large egg yolk contains approximately 18% of the egg – 60% of the egg’s calories, 42% of the egg’s protein, and 31% of the egg’s fat.

So, where does a raw egg yolk come from? As you may already know, chickens are birds, which means they lay eggs. But why do chickens lay eggs in the first place? To answer that question, we must explore the biology behind a chicken egg’s creation and journey.

A chicken egg begins its life in the hen’s ovary, which is composed of several small follicles. Two types of cells exist within these follicles: theca cells, which secrete hormones and provide a supportive framework for the egg; and the granulosa cells, which are responsible for developing the egg itself.

The egg begins its development in the immature follicles and is fed by the blood vessels that supply the ovary. During the fertilization process, sperm is released into the vagina and travels to the uterus. Once the sperm is ejaculated, the ovary begins releasing a hormone called follicle stimulating hormone which triggers the release of the egg from its follicle. As it continues its journey, the egg makes its way up the oviduct and into the oviduct portion of the uterus.

Once the egg enters the uterus, it begins to build layers. The innermost layer of the egg is the yolk membrane, which is composed of a protective, thick protein membrane which helps keep the yolk intact. In the next layer, the perivitelline fluid forms an elastic gel surrounding the yolk to provide a cushion and prevent the yolk from breaking. The supracloacal albumen, or egg white, is comprised of two parts: the chalaziferous layer and the inner albumen, which contains most of the egg’s liquid content.

The shell of the chicken egg is made up of three separate layers. The innermost layer, or the shell membrane, is composed of a type of lipoprotein and phospholipid blend of proteins which create a waterproof barrier for the inner contents of the egg. The middle layer is made up of calcium carbonate which provides strength and rigidity to the shell, while the outer layer is comprised of a lipoprotein mixture which serves to protect the egg from moisture.

Once the raw egg yolk has been created, it must now make its way to the dinner plate. In order to do this, it first needs to be transported from the hen’s reproductive system to a farm. After the egg is laid, it is collected and immediately taken to the farm where it is thoroughly cleaned and stored in a cool and dark place. From there, the egg can be transported to packing areas, processing plants, and eventually grocery stores.

Once the egg has reached the grocery store, consumers have the opportunity to purchase the egg. It is important to note that the egg should not be stored at room temperature for an extended period of time, as bacteria and other contaminants can grow in the warm environment. Instead, eggsshould always be stored in the refrigerator and only taken out shortly before they are to be cooked or eaten.

Once the egg reaches your kitchen, it’s ready to be prepared. When cracking the egg open, it’s important to take care not to damage the yolk, as broken yolks can leak nutrients and make the egg less nutritious. Additionally, cracked eggs should never be consumed raw due to the potential presence of salmonella or other foodborne illnesses. Therefore, it is always recommended to cook eggs completely before consuming.

Whether you’re making sunnyside-up eggs, a rich hollandaise sauce, or mixing egg yolks in for added richness in a cake batter, raw egg yolks bring flavor, nutrition and texture to many dishes. By understanding the biology and science behind raw egg yolk creation and its journey from farm to plate, we are able to appreciate the incredible journey these little yellow centers undergo in order to reach our dinner table.