Meat myoglobin derivatives

MILLAR, s. J., MOSS, B. w. and STEVENSON, M. H. (1996). Some observations on the absorption spectra of various myoglobin derivatives found in meat. Meat Science, 42(3), 277-288. 

In contrast to milk, where samples are primarily derived from cows, meat analysis has to be performed in samples of a widely different animal origin including cattle, lamb, swine, poultry, and fish. Muscle is a complex matrix with a pH of 5.7, composed of muscle fibers, various types of connective tissue, adipose tissue, cartilage, and bones. Sarcoplasmic proteins such as myoglobin, and glycolytic enzymes are soluble in water while the myofibrillar proteins such as myosin and actin are soluble in concentrated salt solutions (14). The connective tissue proteins, collagen and elastin, are insoluble in both solvents. 

Fig. 25 Derivative changes of myoglobin during meat processing. (From Ref. 259.)...

Q5 The average diet in the United Kingdom contains approximately 15 to 20 mg of iron only about 10% of this is absorbed. The main iron content of the diet is haem iron derived from the haemoglobin and myoglobin in red meat, and this is the form of iron which is most readily absorbed. Non-haem iron, for example that derived from cereal products, is less well absorbed. The majority of iron absorption occurs in the duodenum and first part of the jejunum. Non-haem iron absorption is very variable, and some types of food, such as bran and egg yolk, limit its absorption. Gastric acidity helps to keep iron in the ferrous state, which is more easily absorbed than the ferric form. Iron absorption is increased when iron stores are low and when there is increased erythropoietic activity. 

Pig. 3. Derivatives of myoglobin of importance in meats. In the outer circle are represented the insoluble hemochromogens obtained by coagulation. Only in the case of the cured meat pigment is the denatured compound red. Dotted portions represent possible intermediates between metmyoglobin and the cured meat pigment. 

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