Pink Color Defect Research- Dr. James R. Claus

Dr. James R. Claus
(University of Wisconsin-Madison)

A major concern in poultry industry has been with the reoccurring problem
of an uncooked appearance (pink discoloration) in uncured, fully cooked poultry products. Also, in some cases an intense red discoloration in fully cooked poultry is associated with the bone (red discoloration). This discoloration (pink or red) has a direct economic impact on Poultry Processors because consumers will not purchase or consume products that appear to present a health risk based on this color even though the products are fully cooked.

Dr. Claus has identified a unique link to the pinking phenomenon involving ammonia (Photo). In addition, he has provided new knowledge on the impact of endogenous reducing conditions that contribute to the generation of this defect.

Regardless of which native pigments or hemochromes are involved in the pink color defect, the means to control this problem has not been previously reported. Pink hemochromes are formed when certain ligands bind the heme pigments.

In a novel approach to control pink color development, Dr. Claus has determined that it is possible to bind selected ligands to the heme ring that do not cause a pink color (Schwarz et al. 1997). The most recent research indicates that selected dairy proteins can significantly reduce (28 to 72% reduction) the pink defect (Slesinski, 1998). Therefore an immediate and practical way to help control this problem is available.

If there is interest in more detail concerning the mechanisms and control of the pink color defect, an in-plant presentation, workshop or round table discussion can be arranged. Below is an example outline of such a meeting.

Pink Color Defect: Mechanisms and Control

James R. Claus

1. Introduction

2. Fundamentals of meat pigment chemistry

3. Factors affecting pink color generation

4. Mechanisms/pigments involved in the generation of the pink color defect

5. Current research advances relative to the pink color defect

6. Approaches to controlling this defect and recommendations

Schwarz, S. J. 1996. Inhibition of pinking in cooked, uncured turkey rolls through binding of non-pinking ligands to muscle pigments. M.S. Thesis. VPI&SU.

Slensinski, A.J. 1998 (Projected, Fall). Effect of milk proteins on the reduction of pink color development in cooked, uncured turkey breast. M.S. Thesis. VPI&SU.

Slesinski, A.J., Claus, J.R., Anderson-Cook, C.M., Eigel, W.E., Graham, P.P., Lenz, G.E. and Noble, R.B. 2000. Ability of various dairy proteins to reduce pink color development in cooked ground turkey breast. J. Food Sci. 65(3):417-420.

Slesinski, A.J., Claus, J.R., Anderson-Cook, C.M., Eigel, W.E., Graham, P.P., Lenz, G.E. and Noble, R.B. 2000. Response surface methodology for reduction of pinking in cooked turkey breast mince by various dairy protein combinations. J. Food Sci. 65(3): 421-427.

Schwarz, S.J., Claus, J.R., Wang, H. Marriott, N.G., Graham, P.P. and Fernandes, C.F. 1999. Inhibition of pink color development in cooked, uncured turkey breast through ingredient incorporation. Poultry Sci. 78:255-266.

Schwarz, S.J., Claus, J.R. Wang, H., Marriott, N.G., and Graham, P.P. 1998. Quantification of nicotinamide hemochrome in cooked, uncured turkey by reflectance spectrophotometry. J. Muscle Foods 9:101-110.

Schwarz, S.J., Claus, J.R., Wang, H., Marriott, N.G., Graham, P.P., and Fernandes, C.F. 1997. Inhibition of Pink Color Development in Cooked, Uncured Ground Turkey Through the Binding of Non-Pink Generating Ligands to Muscle Pigments. Poultry Sci. 76:1450-1456.

Claus, J.R., Shaw, D.E., and Marcy, J.A. 1994. Pink color development in turkey meat as affected by nicotinamide, cooking temperature, chilling rate, and storage time. J. Food Sci. 59:1283-1285.

Shaw, D.E., Claus, J.R., and Stewart, K.K. 1992. A research note: Effects of ammonia exposure on fresh pork: a distinct pink color after cooking. J. Muscle Foods 3:169-174.