Yellow Chicken Skin and Fat
Color Affects Our Sensories
Color plays an important part in determining what foods we find enticing and delectable to our appetite. Our sensories can affect how healthy we see foods also. Chicken with yellow skin is often seen as a sign of healthy food and good quality chicken. Some whole chickens and skin on chicken parts we see at our grocers are from birds with a yellow skin color because that’s what some people want to see.
The color of a chicken’s skin and fat can range from white to yellow. There are two skin colors in chickens, white skin from the Red Jungle Fowl lines and the yellow skin from the Grey Jungle Fowl most likely. Recent genetic testing has shown that they are from separate lineages. The white skinned birds take in carotenoids but they don’t express the coloring in their skin like the yellow skin do.
Lots of Work Goes into Looks
The yellow skin and fat is created from the chicken’s diet and it isn’t necessarily a sign of quality. Grass fed birds and free range chickens usually have deeper colored yellow fat than their grain fed counterparts. Grass fed and pastured poultry are typically more exposed to food that has more coloring carotenoids.
Along with intensive studies for feed to create yellowness in skin there are more practices to create a yellow skinned bird ranging from feed to processing. When some commercial butchers process birds they can use what is called a soft scald which is about 127 F for 90 seconds because this kind of scald does not remove the cuticle and reduce coloring. There are scales used to measure the yellowness of the skin to properly gauge color. Many methods have been used and are still utilized to increase and maintain yellowness because of its commercial importance. Modern production poultry houses aren’t as concerned as their product goes to be processed into nuggets and other parts.
Birds Cannot Create Carotenoids
Birds as a whole are not able to make carotenoids themselves so they must come from foods that the birds eat. Carotenoid content in chickens are mainly found in the eggs’ yolk, the skin, liver, and fat. The feathers can also show signs of yellowing from carotenoids. Carotenoids are however not just for coloring. They are useful as antioxidants and can be seen working in times of high stress. When stressed it is possible to see coloring washed from the birds most noticeably in the legs.
Natural sources like vegetables supply the yellow compounds in carotenoids. Lutein and zeaxanthin are found in yellow corn and its usual by-products used for feed. Lutein is the major carotenoid in marigolds and alfalfa. Paprika extracts provide red carotenoids like capsanthin and capsorubin however they also contain lutein and zeaxanthin as well.
Carotenoids in modern poultry production most often used include canthaxanthin, zeaxanthin, and lutein. Commercial broiler operations can supply these in natural based feeds like yellow corn, corn gluten meal, and dehydrated alfalfa meal. Soybean meal when added to alfalfa feed can help stabilize carotenes while in storage and prolong its shelf life.
Alongside the natural sources of carotenoids there are also more cost effective means to supply it to a poultry producers flock. Apo–ester, canthaxanthin, and citranaxanthin are commercial sources of carotenoids produced synthetically. Citranaxanthin may be created in a synthetic manner by dissolving trans-β-apo-8′-carotenal in acetone and ethanol. It is created along with potassium hydroxide and nitrogen and extracted with petroleum ether. The resulting compound can be used to either replace or more likely fortify feed to obtain more yellowed skin and fat.
Studies have shown that natural pigments have consistently greater yellowness in skin color. Synthetic sources have shown the largest increase in the color of the egg yolk though. Overall it comes down to providing a cost effective result that producers can profit from and consumers can and will purchase.