MEAT PINKING: AN UNEXPECTED DEFECT

9 Mar 2026

Consumers usually associate cooked meats (other than cured meats) with a brown color. A pink color in fully cooked meat appears unusual and may suggest that the meat is undercooked or spoiled. Although the phenomenon known as meat pinking does not represent a health risk, these unexpected colors are a quality problem that can compromise commercial acceptance.

It usually appears sporadically and irregularly. Sometimes it only affects the surface or part of certain pieces. In other cases, it may affect an entire batch with varying degrees of intensity.

The brown-gray color developed in cooked meat is due to the heat-induced denaturation of the pigments present in raw meat that give fresh meat its characteristic red-pink color. These pigments are myoglobin, hemoglobin, and cytochrome c.

Each of these pigments is present in different concentrations depending on the animal species and the specific muscle involved. They also have different characteristics and denaturation temperatures. Their denaturation temperatures depend on the surrounding environment, but the main ranges are:

  • Myoglobin: 60–70 °C

  • Hemoglobin: 55–65 °C

  • Cytochrome c: 65–80 °C

Factors That Can Cause Meat Pinking

High pH or Reducing Conditions

A pH value above 6 and a reducing environment have a thermoprotective effect on hemochromes and may partially prevent their denaturation.

These conditions may be induced by the addition of certain substances such as phosphates, citrate, pH regulators, or antioxidants. They may also result from the physicochemical conditions of the food during processing, cooling, and storage, or even as a consequence of microbial growth.

Contaminants

Certain substances can react with heme groups and produce thermostable pigments that give cooked meat a persistent pink color.

The most common are nitrites and nitrates. These may originate from cross-contamination in facilities where foods containing these substances are processed, or from other sources such as water, vegetables, or denatured proteins used as ingredients.

Only a few parts per million (ppm) are enough to produce noticeable color defects. Approximate quantities required are:

  • Beef: 14 ppm

  • Pork: 4 ppm

  • Turkey: 2 ppm

  • Chicken: 1 ppm

Carbon monoxide (CO) and nitrogen oxides (NO, NOx) can also combine with heme groups to form thermostable red pigments. Common sources of these contaminants include boilers, ovens, and smokers with improper combustion.

Prevention of Meat Pinking

Preventing the appearance of this defective pink color requires controlling the causes described above.

Because meat pinking is a complex phenomenon involving the interaction of multiple factors—such as meat pigments, pH, redox state, ingredients, contaminants, and cooking conditions—its control requires a detailed understanding of the characteristics and processing conditions of the meat.

Only through this understanding can an integrated formulation and process design be developed to effectively prevent its occurrence.

I hope you found this blog interesting. You might also be interested in a previous blog where we discussed “how to reduce salt and glutamate.”