Does A Bruise On A Chicken Change The Quality Or Taste Of The Meat

Earlier poultry meat quality is addressed, the term quality should be clearly defined equally it relates to poultry. This is a hard task because quality is 'in the eye of the beholder'. For instance, someone trying to sell a product might view its quality in terms of how well it sells and how much people are willing to pay for it. Even so, this definition is incomplete considering information technology does non consider the production'southward graphic symbol.

Since people but buy what they like, the consumer'southward perspective of quality is more appropriate. When consumers buy a poultry product, cook and serve information technology to their families, they expect it to look, taste and feel proficient in their mouth. If these characteristics practise not meet the consumer's expectation, the product is considered to exist of lower quality.

Figure one. Quality attributes of a food product
^{(adapted from Erdtsieck, 1989)}

Whether or not a poultry product meets the consumer's expectations depends upon the conditions surrounding various stages in the bird's development from the fertilized egg through production and processing to consumption. Although there are a number of characteristics that determine the overall quality of meat (Figure 1), the following word will focus only on appearance, texture and season.

Color of cooked or raw poultry meat is important because consumers associate it with the product's freshness, and they decide whether or non to purchase the product based on their opinion of its attractiveness.

Poultry is unique because it is sold with and without its peel. In add-on, information technology is the only species know to have muscles that are dramatic extremes in color (white and dark meat). Breast meat is expected to have a pale pink color when it is raw, while thigh and leg meat are expected to be night red when raw.

There are times when poultry meat does not have the expected colour, and this has created some special issues for the poultry industry.

Advent (Colour)

Poultry meat colour is affected by factors such as bird age, sex, strain, diet, intramuscular fat, meat moisture content, pre-slaughter atmospheric condition and processing variables. Colour of meat depends upon the presence of the musculus pigments myoglobin and haemoglobin.

Discoloration of poultry can be related to the corporeality of these pigments that are present in the meat, the chemical country of the pigments, or the style in which lite is reflected off of the meat. The discoloration can occur in an entire muscle, or it tin be limited to a specific area, such as a trample or a broken claret vessel. When an entire musculus is discolored, it is oft the breast muscle. This occurs because breast muscle accounts for a large portion of the live weight (about 5 per cent), it is more sensitive to factors that contribute to discoloration, and the already light appearance makes modest changes in colour more noticeable.

Extreme ecology temperatures or stress due to live handling before processing can crusade broiler and turkey breast meat to be discolored. The extent of the discoloration is related to each bird'south individual response to the conditions.

Table one. Colour changes in a trample over time for broiler musculus ^{(Gregory, 1992)}
Age	Color
2 minutes	Red
12 hours	Nighttime Crimson-Purple
24 hours	Lite Light-green-Royal
36 hours	Yellowish-Dark-green-Purple
48 hours	Yellow-Green (Orangish)
72 hours	Yellow-Orange
96 hours	Slightly Yellowish
120 hours	Normal, Flesh Colour

Another major cause of poultry meat discoloration is bruising. Approximately 29 per cent of all carcasses candy in the Us are downgraded (reduced quality), and the bulk of these defects (28 per cent) are from bruises (AMS, 1995).

The poultry industry generally tries to identify where (field or plant), how, and when the injuries occur but this is often difficult to decide. The colour of the bruise, the amount of 'blood' present, and the extent of the 'blood jell' formation in the affected surface area are good indicators of the historic period of the injury and may requite some clues as to its origin. A bruise will vary in appearance from a fresh, 'bloody' scarlet colour with no clotting minutes after the injury to a normal flesh colour 120 hours later (Table ane).

The amount of 'blood' present and the extent of clot formation are useful in distinguishing if the injury occurred during catching/transportation or during processing. Injuries that occur in the field are unremarkably magnified past processing plant equipment or handling conditions in the establish.

Texture (Tenderness)

After consumers buy a poultry production, they relate the quality of that product to its texture and flavour when they are eating it. Whether or not poultry meat is tender depends upon the rate and extent of the chemical and physical changes occurring in the muscle as it becomes meat. When an animate being dies, blood stops circulating, and there is no new supply of oxygen or nutrients to the muscles. Without oxygen and nutrients, muscles run out of energy, and they contract and get stiff. This stiffening is called rigor mortis. Somewhen, muscles become soft again, which means that they are tender when cooked.

Annihilation that interferes with the formation of rigor mortis, or the softening process that follows it, will touch on meat tenderness. For example, birds that struggle earlier or during slaughter cause their muscles to run out of energy quicker, and rigor mortis forms much faster than normal. The texture of these muscles tends to be tough because energy was reduced in the live bird. A like pattern occurs when birds are exposed to ecology stress (hot or common cold temperatures) before slaughter. Loftier pre-slaughter stunning, loftier scalding temperatures, longer scalding times and machine picking tin also crusade poultry meat to exist tough.

Tenderness of portioned or boneless cuts of poultry is influenced by the time mail-mortem of the deboning. Muscles that are deboned during early on postmortem still take energy available for wrinkle. When these muscles are removed from the carcass, they contract and go tough.

To avoid this toughening, meat is usually 'aged' for 6 to 24 hours before deboning. However, this is costly for the processor.

When poultry is deboned early on (0 to 2 hours post-mortem), 50 to fourscore per cent of the meat will be tough (Figure 2). On the other hand, if the processor waits 6 hours earlier deboning, 70 to 80 per cent of the poultry meat will be tender.

The poultry industry has recently started using postal service-slaughter electric stimulation immediately later on death to hasten rigor evolution of carcasses and reduce 'aging' time before deboning. This is different from energy depletion in the live bird, which causes meat to be tough. When electricity is applied to the dead bird, the treatment acts like a nerve impulse, and causes the muscle to contract, employ up energy and enter rigor mortis at a faster rate.

In the live bird, the aforementioned treatment causes meat to be tough but after death, the handling causes tender deboned poultry meat within two hours mail service-mortem instead of the four to six hours required with normal crumbling.

Although electrical stimulation is still in the developmental stages, information technology seems that processors using it can debone carcasses right out of the chiller and save on their equipment costs, time, space and energy requirements.

Figure 2. The effect of deboning time on cooked meat tenderness
^{(Lyon & Lyon, 1009; Fletcher, 1997)}

Flavour

Flavour is another quality attribute that consumers apply to determine the acceptability of poultry meat. Both gustatory modality and odour contribute to the flavour of poultry, and it is generally hard to distinguish between the two during consumption (Figure 3).

When poultry is cooked, flavour develops from saccharide and amino acid interactions, lipid and thermal oxidation and thiamin degradation. These chemical changes are not unique to poultry only the lipids and fats in poultry are unique and combine with aroma to business relationship for the characteristic 'poultry' season.

Few factors during product and processing affect poultry meat flavour. This ways that it is not only difficult to produce a flavour defect just it is hard to enhance flavour during production and processing.

Age of the bird at slaughter (young or mature birds) affect the flavour of the meat. Minor effects on meat season are related to bird strain, diet, environmental weather (litter, ventilation, etc.), scalding temperatures, chilling, product packaging and storage. Still, these effects are as well small for consumers to notice.

Figure iii. Flavour perceptions
^{(adjusted from Lawless, 1991)}

Conclusion

The most important aspect of poultry meat is its eating quality – the land of the animal at slaughter. Poultry processing affects meat quality by establishing the chemical science of the muscle constituents and their interactions inside the muscle structure. The producer, processor, retailer and consumer all have specific expectations for the quality attributes of poultry in Figure 1 but the ultimate authorization will always exist the consumer.

References

Agricultural Marketing Service. 1995. Poultry Grade Yield Report, Poultry Grading Branch, United States Department of Agriculture, Washington, D.C.
Erdtsieck, B. 1989. Quality requirements in the modernistic poultry manufacture. In Processing of Poultry (G. C. Mead, ed.) pp. 1-30. Elsevier Applied Scientific discipline, New York.
Fletcher, D.L. 1997. Quality of Poultry Meat: Texture and Colour. Proceedings Georgia International Poultry Course, Athens, GA.
Gregory, Northward.Chiliad. 1992. Catching Damage. Broiler Industry 55:14-16.
Lawless, H. 1991. The sense of smell in food quality and sensory evaluation. J. Nutrient Quality 14:33-threescore.
Lyon, B.One thousand. and C.E. Lyon. 1991. Research Note: Shear value ranges by Instron Warner-Bratzler and single-bract Allo-Kramer devices that correspond to sensory tenderness. Poultry Science seventy:188-191.

February 2009