Color, pigments myoglobin

The color of red meat depends on oxygen. The color of the meat pigment myoglobin is purple. The bright red color of the fresh-as-cut meat is from oxymyoglobin. To preserve red meat, the objectives are to retard spoilage and weight loss, and to deUver red color at the consumer level. 

In fresh meat, in the presence of oxygen, the reversible reaction of myoglobin (Mb) with oxygen occurs and results in the formation of bright-red-colored oxy-myoglobin (Mb()2). In both pigments the iron is in ferrous form, and upon oxidation to ferric state, the brownish metmyoglobin (MMb) is formed. 

Love and Pearson (6) have described a model meat system in which bovine muscle was ground and extracted with distilled, deionized water at 4°C until it was devoid of color, indicating the removal of all meat pigments, i.e., myoglobin and hemoglobin. Other water-soluble components would also be partially or completely extracted by this procedure. The remaining extracted muscle was then used as a model system to which purified myoglobin, ferrous iron and ferric iron were added back to ascertain their role in WOF. 

HPs are effective for the extraction of metabolites that function as pigments or flavorings permit the selective proteolysis of proteins that is important for the elaboration of modified milk for babies and allow the inhibition of the Maillard reaction among others (Barbosa-Canovas et al., 1998). However, it has been observed that the color of food can be affected by pressure. Within the more resistant pigments are the carotenoids, chlorophyll and anthocyanines, while myoglobin is more sensible (Cheftel, 1992). 

The color of foods is attributed to the presence of natural pigments (including hemes, myoglobins, chlorophylls, anthocyanins, carotenoids, betacyanins) and added colorants. During food processing and storage, color changes result from the... 

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