Reader Linda See wrote in to ask about the differences between kampung/free-range chicken eggs, those laid by black chickens and generic brown eggs: "How do we differentiate between these eggs? Do kampung/free-range eggs and black chicken eggs have more nutritional value than generic eggs?"
Food reporter Kenneth Goh finds out.
According to Ms Petrina Lim, who heads the Centre for Applied Nutrition Services at Temasek Polytechnic's School of Applied Science, it is difficult to use the attributes of eggs, such as the colour of the egg yolk, to determine the breed of chickens that they come from.
The colour of the yolk is reflective of the type of feed that the hens are given.
If the hens feed on wheat, they produce pale-yellow yolks, while those that feed on green plants or are on corn-based diets produce yolks that are darker in colour.
The shells of eggs from kampung chickens are light brown in colour, while those from black chickens, which belong to the Silkie breed, are cream or brown in colour.
Eggs from kampung and black chickens are smaller than generic eggs. Nutrition-wise, contrary to what many believe, the nutritional value of kampung and black chicken eggs is not necessarily higher than that of generic eggs.
Eggs have the same protein and fat content, regardless of their colour or grade.
Eggs also contain 14 essential vitamins and minerals, such as Vitamins A, D and E, as well as antioxidants. But some egg producers have come up with "designer eggs" by altering the feed of the hens with specific nutrients such as Omega-3.
These nutrients are passed from the hen's diet into the eggs.