68 Chilled foods steers, and cows(55 to 108 months old). No differences were found between the tenderness of bulls and steers. Tenderness decreased with the age of the animal Hawrysh et al. reported that beef from bulls may be less tender than that from steers. Sex can have a substantial influence on flavour. For example, cooking the meat from entire male pigs can produce an obnoxious odour known as"boar taint. Problems can also occur with meat from intact males of other species However, they can still be attractive to industry because of their higher rate of growth and lower fat content 3.2.3 Feeding le way in which an animal is fed can influence its quality and storage life. It has been reported that chops from pigs fed on household refuse have half the frozen storage life of those fed on a milk/barley ration. 7, 18 Again, pork from pigs that had been fed materials containing offal had half the practical storage life(Psl)and higher iodine numbers in the fat than that of pigs which had no been fed this type of diet. Conversely, Bailey et al.- did not find differences between meal- and swill-fed pigs after 4 and 9 months at -20oC Rations with large amounts of highly unsaturated fatty acids tend to produce more unstable meat and fat The type of fatty acid composition of ' depot fatin poultry and its stability have been shown to be directly related to the fatty acid composition of ingested fats.1,2 The feeding of fish oils or highly unsaturated vegetable oils(s linseed oil) to poultry is known to produce fishy flavours in the mear uch as The use of vitamin E supplements is recommended for both beef and turke This willresult in delayed onset of discoloration in fresh, ground and frozen beef and in suppression of lipid rancidity, especially in fresh, ground and frozen in cooked beef with turke been shown to improve oxidative stability of cooked and uncooked turkey burgers during six months frozen storage at -20oC25 3.2.4 Variations within an animal Reports of variations in the storage life of different cuts of meat e scarce and primarily deal with dark and light meat. Both Ristic26 and Keshinel et al.27 have found that poultry breast meat stores better than thigh meat. Ristic states that frozen breast meat will store for 16 months while thigh meat can be stored for only 12 months due to its higher fat content. Judge and Aberle- also found that light pork meat stored for a longer time than dark meat. This was thoug to be due to either higher quantities of haem pigments in the dark muscle (which may act as major catalysts of lipid oxidation), or to higher quantities of phospholipids(which are major contributors to oxidised flavour in cookedsteers, and cows (55 to 108 months old). No differences were found between the tenderness of bulls and steers. Tenderness decreased with the age of the animal. Hawrysh et al.16 reported that beef from bulls may be less tender than that from steers. Sex can have a substantial influence on flavour. For example, cooking the meat from entire male pigs can produce an obnoxious odour known as ‘boar taint’. Problems can also occur with meat from intact males of other species. However, they can still be attractive to industry because of their higher rate of growth and lower fat content. 3.2.3 Feeding The way in which an animal is fed can influence its quality and storage life. It has been reported that chops from pigs fed on household refuse have half the frozen storage life of those fed on a milk/barley ration.17, 18 Again, pork from pigs that had been fed materials containing offal had half the practical storage life (PSL) and higher iodine numbers in the fat than that of pigs which had not been fed this type of diet.19 Conversely, Bailey et al.20 did not find any differences between meal- and swill-fed pigs after 4 and 9 months at
20ºC. Rations with large amounts of highly unsaturated fatty acids tend to produce more unstable meat and fat. The type of fatty acid composition of ‘depot fat’ in poultry and its stability have been shown to be directly related to the fatty acid composition of ingested fats.21, 22 The feeding of fish oils or highly unsaturated vegetable oils (such as linseed oil) to poultry is known to produce fishy flavours in the meat.21, 23 The use of vitamin E supplements is recommended for both beef and turkey. This will ‘result in delayed onset of discoloration in fresh, ground and frozen beef and in suppression of lipid rancidity, especially in fresh, ground and frozen beef and less so in cooked beef’. 24 With turkey, vitamin E supplements have been shown to improve oxidative stability of cooked and uncooked turkey burgers during six months frozen storage at
20ºC.25 3.2.4 Variations within an animal Reports of variations in the storage life of different cuts of meat are scarce and primarily deal with dark and light meat. Both Ristic26 and Keshinel et al.27 have found that poultry breast meat stores better than thigh meat. Ristic states that frozen breast meat will store for 16 months while thigh meat can be stored for only 12 months due to its higher fat content. Judge and Aberle28 also found that light pork meat stored for a longer time than dark meat. This was thought to be due to either higher quantities of haem pigments in the dark muscle (which may act as major catalysts of lipid oxidation), or to higher quantities of phospholipids (which are major contributors to oxidised flavour in cooked meat). 68 Chilled foods