Poultry Meat Quality
What factors impact poultry meat quality?
The conversion of muscle to meat is a complex process influenced by several internal and external factors, including animal genetics, nutrition, management, pre-slaughter handling, stunning and post-slaughtering methods. The term “meat quality” covers properties related to consumer acceptance, such as flavor, tenderness, juiciness, color, safety and consistency. Traditionally, feed formulations have been based on requirements for optimal animal health and growth. However, the correlation between nutrition, key biological processes and meat quality has become a focus as consumer preference drives meat sales.
Meat quality factors that matter to consumers
- Color: Consumers rely heavily on color as an indicator of freshness. It has been estimated that price discounts due to product discoloration result in a $1-billion loss of revenue in the United States (Smith et al., 2000; Suman and Joseph, 2013).
- Water-holding capacity: The ability of meat to retain moisture throughout storage and cooking — referred to as its water-holding capacity — dictates juiciness. Fresh meat is approximately 75% water, with the majority embedded in the muscle matrix known as the myofibrillar lattice. This lattice is made up of smaller components called thick and thin filaments, whose properties influence the meat’s water-holding capacity. Chemical, physical or enzymatic processes that cause the myofibril lattice to expand can improve the meat’s water-holding capacity.
- Tenderness: Tenderness is another important and complex quality attribute that influences consumer acceptance. Various structural and metabolic factors — such as the amount of connective tissue, the final pH, post-mortem muscle contractions and the activity of proteolytic enzymes during the conversion of muscle to meat — dictate tenderness.
- Palatability: Palatability is a key factor in the consumer acceptance of meat. Oxidative damage to lipids and proteins during storage not only decreases juiciness and tenderness but also produces rancid off-flavors. Oxidation occurs when unsaturated phospholipids, heme pigments, free metal catalysts and other oxidizing agents are present in the muscle tissue. Incorporating dietary antioxidants and other functional feed ingredients can minimize free radical formation, slow lipid and protein oxidation, and improve the palatability of fresh meat.
Nutrition’s role in poultry meat quality
Oxidation is a leading cause of consumer dissatisfaction with meat products. Reducing oxidation is one area in which nutrition could make a significant impact on meat quality — especially by increasing the level of endogenous antioxidants in the meat.
The form and amount of minerals used can impact the oxidative stability of meat. Several microminerals are cofactors of antioxidant function (e.g., selenium for glutathione peroxidase and zinc and manganese for super oxide dismutase), comprising an important enzymatic defense system against cellular oxidation. However, the delivery and absorptive properties of microminerals can be either beneficial or detrimental to meat quality if the minerals are not fully absorbed. Especially at higher dosages, inorganic minerals can accelerate oxidative processes due to the dissociation of the mineral metal from the ligand. The higher bioavailability and lower reactivity of proteinate trace minerals allow them to function strongly and more effectively in these roles.
At supra-nutritional levels, vitamin E (α-tocopherol), a fat-soluble antioxidant, scavenges free radicals, leading to lower lipid oxidation and the formation of metmyoglobin (i.e., brown coloring). The amount of vitamin E required and the length of feeding will vary depending on the use of other feedstuffs.
Nutrition, combined with good management and genetics, plays a key role in meat quality. In order to maximize the flavor, tenderness, juiciness, color and consistency of meat products, it is crucial to provide animals with diets that reduce their oxidative potential, increase their water-holding capacity and maximize their antioxidant activity.