CHICKEN PROCESSING: Chicken Value Chain: From Farm to Fork
The Chicken Value Chain
Have you ever wondered where that tasty piece of chicken you eat at your favourite restaurant comes from? The journey from farm to fork takes three to five months of carefully planned logistics and quality control to ensure only safe and hygienic products are consumed.
Chicken, being a very sensitive product, has to be handled carefully lest consumers are harmed through food poisoning. This article looks at the typical chicken supply chain and the efforts of the many players who go to all lengths to ensure a safe and delicious product lands on the consumer's plate. The journey begins at the hatchery, then the breeding farm, slaughterhouse, processing units, distribution, retail outlets and finally to the hands of the final consumers.
The process starts with the hatchery where the eggs are put into an incubator and left for 21 days after which they are housed in breeding farms. High hygiene standards are maintained to ensure that the flock does not suffer from contagious poultry disease which can wipe them out in a very short time. Staff working in chicken hatcheries have to under-go medical tests and wear protective clothing every time they are near the incubators. Modern day incubators are able to handle a very large number of eggs and the quantity produced in one batch can be as high as one million chicks.
Breeding is a very scientific process that requires accuracy in feeding because the sizes of chicken bred should exactly match the required weight.
Receiving of Birds
The birds are moved from the farmers and received at the processing plant where they are weighed in bulk. This live weight is what determines the payment to the farmer. Quality checks are carried out here and any carcasses are separated from the flock for determination of the cause of death. If the death was caused by a disease on the farm side the whole consignment is rejected especially if the disease is contagious. Other causes of death can be because of environmental factors such as heat stress and extreme cold. The good birds are removed from the crates and manually shackled on to the moving line to proceed to the next process, which is stunning.
The most common way of stunning is to immerse the birds head first into an electrified water tank. This method is considered humane as the birds are not subjected to unnecessary pain and anguish. There are also religious considerations especially for Jews and Muslims who have to observe Kosher and Halal respectively. After stunning, the birds are still alive but immobile and they move along the line to the bleeding section.
Bleeding of Birds
Here, the jugular of the bird is cut at the neck just below the jowl. This allows for ease of removal of the wind-pipe and oesophagus during the evisceration stage. The movement along a short length of an automated line ensures that all the blood has dripped completely before entering the next stage.
This is the loosening of the feathers by immersing the bird in a tank with water heated to 128 degrees Fahrenheit. Still attached to the moving shackle line, the bird is immersed for about 50 - 120 minutes. The temperature and time in the scalding tank is carefully controlled to avoid the damage of the skin or epidermis and therefore downgrading of the bird. If it is kept for too long in hot water, the skin normally comes off during the de-feathering stage.
A mechanical plucking machine with rotating rubber fingers rubs the feathers off the bird. It should be noted here again that the bird is moving in a continuous flow in the shackling line and this continues up to the chilling stage. The few feathers that remain after the plucking process are removed manually by the staff in this section.
Chicken Evisceration Process
This is the removal of all the internal organs which is done in the following sequence:
- Opening cuts
- Viscera pulling
- Giblet removal
- Lung removal
- Head removal
- Crop and windpipe removal
This process is normally done using a sharp knife and metal scoop to ensure that the contents of the gut do not contaminate the carcass. If this were to happen the bird is condemned and cannot be used as human food. However,if the spillage is minimal, thorough washing is allowed and the carcass can be used for human consumption. After the abdominal skin has been cut and all the viscera removed, the internal organs are inspected for signs of disease.
Washing and chilling process
After the giblets, lungs, windpipe, head and crop are removed, the birds are dropped into a water tank that has revolving blades that move them forward. The water is a solution of a sanitizing agent such as chlorine which kills all micro-organism in the bird. All loose dirt and blood is also washed out in the process. The forward motion moves the carcasses to the chilling tank in which water is chilled to 32 degrees Fahrenheit. The purpose of chilling is to reduce microbial growth as low temperatures keep the few remaining micro-organisms in a suspended state.
Chicken Grading Process
The chicken are then sorted based on the customer demand and specifications. There are very many grades of chicken and this is determined by the market that the processing plant is supplying to. Examples of different grading categories are:
- Spring chicken
- Roasting chicken
- Broiler or fryer
The list above is by no way exhaustive as there is further classification depending on the weight of the bird and the further processing that is required.
Distribution and Further Processing of Chicken
After grading the birds are package and distributed for further processing and final consumption. The whole birds are cut-up into various categories for use in restaurants and domestic consumption. Examples of cut-ups are:
- Chicken breasts
- Thigh boneless
- Thigh on bone
- Chicken legs
Other chicken parts like the giblets, skin and wish bones are also packaged for the local market.