Colour changes in chilling, freezing and storage of meat The appearance of meat at its point of sale is the most important quality attribute governing its purchase. The ratio of fat to lean and the amount of marbled fat are important appearance factors and another is the colour of the meat. The changes in colour of the muscle and blood pigments (myoglobin and haemoglobin, respectively) determine the attractiveness of fresh red meat, which in turn influences the consumers acceptance of meat products(Pearson, 1994). Consumers prefer bright-red fresh meats, brown or grey-coloured cooked meats and pink cured meats(Cornforth, 1994) Reviews of the affect of chilling and freezing on the colour of meat were carried out by MacDougall in 1972 and 1974, respectively. The principle factors governing colour changes from those reviews have been included ir 4.1 Meat colour Objects appear coloured when some wavelengths of light are selectively absorbed. meat looks red because it absorbs all other colours other tha red, which is reflected. When meat is examined in reflected light its colour will depend on (1) the nature of the illuminating light, and(2)changes taking place during reflection Light sources contain a varying spectrum of intensities and wavelengths and meat viewed in tungsten light, for example, will appear redder because of the abundance of red light produced by the source. The physical structure of the meat and the chemical changes to the pigment govern the changes taking place during reflection4 Colour changes in chilling, freezing and storage of meat The appearance of meat at its point of sale is the most important quality attribute governing its purchase. The ratio of fat to lean and the amount of marbled fat are important appearance factors and another is the colour of the meat. The changes in colour of the muscle and blood pigments (myoglobin and haemoglobin, respectively) determine the attractiveness of fresh red meat, which in turn influences the consumers acceptance of meat products (Pearson, 1994). Consumers prefer bright-red fresh meats, brown or grey-coloured cooked meats and pink cured meats (Cornforth, 1994). Reviews of the affect of chilling and freezing on the colour of meat were carried out by MacDougall in 1972 and 1974, respectively. The principle factors governing colour changes from those reviews have been included in this chapter. 4.1 Meat colour Objects appear coloured when some wavelengths of light are selectively absorbed. Meat looks red because it absorbs all other colours other than red, which is reflected. When meat is examined in reflected light its colour will depend on (1) the nature of the illuminating light, and (2) changes taking place during reflection. Light sources contain a varying spectrum of intensities and wavelengths and meat viewed in tungsten light, for example, will appear redder because of the abundance of red light produced by the source. The physical structure of the meat and the chemical changes to the pigment govern the changes taking place during reflection