Have you ever wondered why the colour of egg york matter and what its means?
Well, Peter Alaru, an Animal and Food Scientist and the Coordinator of the Non-Ruminant Research Program at the Kenya Agricultural and Livestock Research Organisation (KALRO), explains this.
Alaru says that the colour of egg yolk is primarily influenced by the raw materials in chicken feed or the levels of carotenoids in feed additives.
He notes that farmers can manipulate the yolk colour, as it
is often perceived as an indicator of egg quality.
"While some people prefer the deep yellow yolk,
thinking it’s more appealing than the paler one, the yolk is just as nutritious
as the albumen," Alaru states.
The colour of the yolk is also determined by the chicken's
diet.
"Indigenous chickens that roam freely tend to
have a deeper yellow yolk, as they feed on a variety of foods, including
insects," he adds.
The nutritional content of the feed plays a key role in
determining the yolk color.
"Currently, some feed companies add additives to their
feeds to enhance the yellow colour of the yolk."
Alaru states that eggs are widely regarded as a
cost-effective and readily available source of nutrition, providing a balanced
mix of essential nutrients crucial for overall growth and well-being.
Eggs are especially important when introduced as solid
foods at an early age, helping support children's development.
He further explains that eggs possess health-promoting
properties, serving as an economical, low-calorie source of high-quality
protein and essential nutrients.
"Eggs are a high-quality protein source, particularly
when cooked, with a protein rating of 91 per cent," Alaru says.
"They contain nine essential amino acids, such as
histidine and isoleucine, which are important for efficient protein utilisation
in the body. Amino acids are crucial for the synthesis of enzymes, hormones,
DNA components, and other essential substances."
In addition to protein, eggs are a valuable source of choline, a nutrient vital
for memory and cognitive functions in the brain.
They also contain approximately 70 milligrams of omega-3
fatty acids, which are important for fetal brain and nerve development,
reducing the risk of heart disease, mental health disorders, and inflammation.
Other nutritional benefits of eggs include a range of vitamins and minerals.
Eggs contain fat-soluble vitamins (A, D, E, and K) as well as water-soluble vitamins, such as thiamine (B1), riboflavin (B2), pantothenic acid (B5), pyridoxine (B6), biotin (B7), folate (B9), cobalamin (B12), and choline.
The amounts of B2 and B12 in eggs are notably high, while B5, B9, A,
and D are present in moderate quantities.
Alaru highlights that folate in eggs can reduce the risk of
neural tube defects in babies.
"Eggs also provide essential minerals like calcium,
iron, magnesium, phosphorus, selenium, sodium, and zinc," he states.
"Additionally, they contain antioxidants that combat
harmful substances generated within the cells. For example, selenium helps
mitigate oxidative stress and reduces the likelihood of heart problems. The
carotenoids in egg yolk can prevent eye issues such as cataracts and
age-related macular degeneration, while vitamin E helps protect fats in the
blood, improving cholesterol movement and reducing the risk of heart
disease."