Meat Color


(1) To demonstrate the relationship between myoglobin and meat color.

(2) To show how the chemical state of myoglobin is related to meat color.

(3) To identify factors associated with the discoloration of fresh meat.

Reading material: Principles of Meat Science (3rd Edition), chapter 6, pages 126 to 131.

Heme pigment found in myoglobin


Heme pigment


Hemoglobin — transports O2 from lungs to cells

Myoglobin — stores O2 in cells

Meat color is impacted by the following factors:

(1) Quantity of myoglobin

(a) Age within species — myoglobin loses its affinity for oxygen as age increases.

Myoglobin differences: Age within species

Age classMyoglobin content
Veal2 mg/g
Calf4 mg/g
Young beef8 mg/g
Old beef18 mg/g

(b) Species differences — age related as well as differences between “red” versus “white” muscle fibers.

Myoglobin differences: Species effects

SpeciesColorMyoglobin content
PorkPink2 mg/g
LambLight red6 mg/g
BeefCherry red8 mg/g

(c) Type of muscle

Myoglobin differences: Muscle effects

MuscleNameMyoglobin content
LocomotiveExtensor carpi radialis12 mg/g
SupportLongissimus dorsi6 mg/g

(2) Chemical state of myoglobin

Chemical state of myoglobin -- Ferrous or Fe++ (covalent bonds)

:NOCured pinkNitric oxide myoglobin

Chemical state of myoglobin -- Ferric or Fe+++ (ionic bonds)



Meat color triangle

(3) Metmyoglobin Reducing Activity (MRA)

deoxymyoglobin —> oxymyoglobin —> metmyoglobin —> deoxymyoglobin —> etc.

Differs according to muscle: some high in MRA (longissimus dorsi), some low in MRA (biceps femoris)

(4) Cooked color problems
Premature Browning
  • Usually caused by highly oxidized meat or meat that is exposed to high-oxygen atmospheres
  • Meat will turn brown around 130°F internal temperature
  • Reason why color is not a good indicator of cooked meat
Persistent Pinkness
  • Usually caused by high pH meat
  • Product will stay pink (uncooked color) even with degrees of doneness that should ensure appropriate cooked endpoint are followed.

(5) Vitamin E feeding of cattle

Vitamin E can be fed to livestock to increase the alpha-tocopherol concentration in muscle. Alpha-tocopherol is an antioxidant and retards the conversion of deoxymyoglobin and oxymyoglobin to metmyoglobin.

(6) Activity of bacteria

PigmentCatalystNew pigment
OxymyoglobinOxidation + bacteriaMetmyoglobin (-OH)
MetmyoglobinBacteriaCholeglobin (-H2O2
MetmyoglobinBacteriaSulfmyoglobin (-SH)

(7) Curing

Plus NONitric oxide myoglobinPlus heatNitrosyl hemochromogen

(8) Wrapping film

Vacuum packages (polyvinylidene chloride-polyvinyl chloride); barrier to O2

Retail film (polyvinyl chloride); permeable to O2

Review of Material — What the student should know:

(1) What causes meat to have a particular color.

(2) The role of bacteria in color development and maintenance.

(3) The influence of oxygen on meat color.

(4) The chemistry behind myoglobin and meat color.

Links to related sites


J.W. Savell, revised July, 2015

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