4 Meat refrigerati There can also be significant differences within a breed Longissimus dorsi shear force values for double muscled Belgium Blue bulls were sig- nificantly higher than those of the same breed with normal conformation (Uytterhaegen et al., 1994). Calpain I levels at 1h and 24 h post-mortem were also much lower. It was suggested that the lower background tough ness in the double muscled was compensated for by reduced post-mortem proteolytic tenderisation Again, castration appears to have little influence on tenderness. Huff and Parrish(1993)compared the tenderness of meat from 14-month-old bulls and steers Strip loins were removed from carcasses ca. 24 h post-mortem found between the tenderness of bulls and steel \s. no differences were vacuum packed and held at 2C for up to 28 day Experiments designed to determine the effect of treatments immediately before or at the point of slaughter appear to show that they have little effect on meat texture Exercising pigs before slaughter has been shown to have no effect on texture parameters, i.e. muscle shortening and shear force (Ivensen et aL., 1995). The use of different stunning methods(both electri- cal and carbon dioxide) does not seem to have a significant effect on the quality of pork( Garrido et aL., 1994) Consumers' surroundings influence their appreciation of tenderness (Miller et aL, 1995). Consumers were more critical of the tenderness of beef steaks cooked in the home than those cooked in restaurants the Warner-Bratzler force transition level for acceptable steak tenderness was between 4.6 and 5.0kg in the home and between 4.3 and 5.2 kg in restau rants. Warner-Bratzler tests are probably the most uniformly used method of texture measurement. However, there are many other methods of deter mining the mechanical properties of meat(Lepetit and Culioli, 1994). In cooked meat it is suggested that applying mechanical tests in different strain directions is likely to produce information that can be more readily related to perceived texture End-point temperature after cooking is crucial to tenderness. Davey and Gilbert (1974) showed that there was a three-to four-fold toughening occurring between 40 and 50C and a further doubling between 65 and Refrigeration has two critical roles in meat tenderness. One is in the prevention of muscle shortening in the period immediately following slaughter. The second is in the conditioning of the meat so that the desired degree of tenderness is obtained 3.1 Muscle shortening Chilling has serious effects on the texture of meat if it is carried out rapidly when the meat is still in the pre-rigor condition, that is, before the meat pH has fallen below about 6.2(Bendall, 1972). In this state the muscles containThere can also be significant differences within a breed. Longissimus dorsi shear force values for double muscled Belgium Blue bulls were sig￾nificantly higher than those of the same breed with normal conformation (Uytterhaegen et al., 1994). Calpain I levels at 1 h and 24h post-mortem were also much lower. It was suggested that the lower background tough￾ness in the double muscled was compensated for by reduced post-mortem proteolytic tenderisation. Again, castration appears to have little influence on tenderness. Huff and Parrish (1993) compared the tenderness of meat from 14-month-old bulls and steers. Strip loins were removed from carcasses ca. 24 h post-mortem, vacuum packed and held at 2°C for up to 28 days. No differences were found between the tenderness of bulls and steers. Experiments designed to determine the effect of treatments immediately before or at the point of slaughter appear to show that they have little effect on meat texture. Exercising pigs before slaughter has been shown to have no effect on texture parameters, i.e. muscle shortening and shear force (Ivensen et al., 1995). The use of different stunning methods (both electri￾cal and carbon dioxide) does not seem to have a significant effect on the quality of pork (Garrido et al., 1994). Consumers’ surroundings influence their appreciation of tenderness (Miller et al., 1995). Consumers were more critical of the tenderness of beef steaks cooked in the home than those cooked in restaurants. The Warner–Bratzler force transition level for acceptable steak tenderness was between 4.6 and 5.0 kg in the home and between 4.3 and 5.2 kg in restau￾rants. Warner–Bratzler tests are probably the most uniformly used method of texture measurement. However, there are many other methods of deter￾mining the mechanical properties of meat (Lepetit and Culioli, 1994). In cooked meat it is suggested that applying mechanical tests in different strain directions is likely to produce information that can be more readily related to perceived texture. End-point temperature after cooking is crucial to tenderness. Davey and Gilbert (1974) showed that there was a three- to four-fold toughening occurring between 40 and 50°C and a further doubling between 65 and 70 °C. Refrigeration has two critical roles in meat tenderness. One is in the prevention of muscle shortening in the period immediately following slaughter. The second is in the conditioning of the meat so that the desired degree of tenderness is obtained. 3.1 Muscle shortening Chilling has serious effects on the texture of meat if it is carried out rapidly when the meat is still in the pre-rigor condition, that is, before the meat pH has fallen below about 6.2 (Bendall, 1972). In this state the muscles contain 44 Meat refrigeration