Marination and Water-Holding Capacity of Broiler Meat

One of the most important properties of poultry meat is it's ability to bind and retain innate water (water-holding capacity or WHC) as well as added water during marination. The type of muscle proteins primarily responsible for WHC and marinade pick-up/retention are the myofibrillar or structural proteins (actin, myosin and the combined structure actomyosin). Table 1 describes the myofibrillar proteins, along with two other types of proteins found in all muscles. When meat is marinaded, it is thought to pick-up solution in the spaces between the thick and thin filaments of the myofibrils (Figure 1). Thus, anything which affects the spacing between the thick and thin filaments will affect marinade pick-up/retention.

Marination historically referred to soaking meat in a solution containing sugar, seasonings or spices, oils, acids (vinegar or fruit juices) or salts. Initially performed to preserve meat (acid marinades), marination was later found to improve flavor, tenderness, juiciness and aroma. The key ingredients for poultry marinades is salt and phosphate. The USDA does not restrict use of salt in marination, but phosphate concentration in the final product must be below 0.5%. Some of the factors which affect the action of salt and phosphate include: 1) initial meat pH; 2) time after death or extent of rigor development; 3) temperature; and 4) mode of application (tumbling or needle injection). Salt increases marinade pick-up by increasing the space between the thick and thin filaments. Phosphates increase meat pH, which increases WHC because proteins are charged (positively or negatively) at the higher pH values.

Practical Applications:

Marination of poultry meat deboned from carcasses immediately after chilling (still in rigor mortis) will have reduced quality characteristics. Young and Lyon (1997) found that marination of early deboned broiler breast fillets resulted in cooked meat that was 60% tougher than non-marinated, early deboned fillets.

Broiler breast fillet marination pick-up and retention varies with fillet color and initial fillet pH. Allen et al. (1998) compared marination characteristics and WHC of "lighter than normal" fillets and "darker than normal"fillets and found that color of fillets and pH were highly correlated with WHC and marination pick-up/retention. "Lighter than normal" fillets had an initial pH of 5.8, marination pick-up of 6%, 5.88% drip loss and 34.4% cook loss. "Darker than normal" fillets had an initial pH of 6.02, 7.67% marination pick-up, 3.34% drip loss, and 32.9% cook loss.

Based on these findings, it could be advantageous for plants that further process poultry to sort products based on color and divert darker colored fillets for marination.

TABLE 1: Types of Muscle Proteins and Their Characteristic

Property	Sarcoplasmic	Myofibrillar	Stromal
Common names	Myoglobin, Residual Hemoglobin, Enzymes	Actin, Myosin, Actomyosin	Connective Tissue, Collagen
Solubility	Soluble in Water	Salt Soluble (>0.4 M salt)	Insoluble
Water-Holding Capacity	Very Low	Very High (particularly in presence of salt and phosphate)	None
Structure in fresh meat	Globular (round)	Fibers	Fibers
Contribution to meat quality	Color and Appearance	Texture (Tenderness)	Texture (Tenderness)

References:

Acton, J.C. and J. Jensen, 1994. Understanding marinade technology. Poultry Processing 9(1):18-22.

Allen, C.D., D. L. Fletcher, J.K. Northcutt, and S.M. Russell, 1998. Relationship of broiler breast color to meat quality and shelf-life. Poultry Sci. 77:361-366.

Offer, G. and P. Knight, 1988. "The structural basis of water-holding in meat" in Developments in Meat Science, volume 4. Ed by R. Lawrie. Elsevier Applied Sci. New York, N.Y.

Young, L.L., and C.E. Lyon, 1997. Effect of postchill aging and sodium tripolyphosphate on moisture binding properties, color and Warner-Bratzler shear values of chicken breast meat. Poultry Sci. 76:1587-1590.

By Julie K. Northcutt, Extension Poultry Scientist
Poultry Tips - College of Agricultural and Environmental Sciences
University of Georgia Cooperative Extension Service