A comparison of the quality characteristics of goat meat with that of sheep meat

Abstract

The purpose of this study was to ascertain how the quality characteristics of Angora and Boer goat meat compare with those of sheep meat. The quality characteristics of the Mm. longissimus thoracis et lumborum of the various age groups and fat codes of Angora and Boer goat meat, prepared according to a dry heat cooking method, were compared with those of the identically prepared Mm. longissimus thoracis et lumborum of the corresponding age groups and fat codes of sheep meat. Thereupon the quality characteristics of the M. semimembranosus of the various age groups and fat codes of Angora and Boer goat meat, prepared according to a moist heat cooking method, were compared with those of the identically prepared M. semimembranosus of the comparable various age groups and fat codes of sheep meat. Triplicate sets of comparable cuts from each age group and fat code were evaluated, thus 27 sheep, 27 Angora and 27 Boer goats were compared. Species affected cooking yield. Sheep meat showed significantly greater drip loss than Boer and Angora goat meat and more evaporation loss than Angora goat meat. On the other hand, sheep and Boer goat meat had greater total cooking losses than Angora meat. The aroma of the sheep meat was more intense, it was more juicy, more tender, contained less fibrous tissue residue, the flavour was more acceptable and the species flavour more typical than that of the Angora and Boer goat meat. The Angora goat meat was more juicy, more tender and contained less fibrous tissue residue than the Boer goat cuts. This was confirmed by the expressible moisture and shear force resistance measurements, respectively. Sheep meat contained more expressible moisture than the goat meat. Sheep meat showed less resistance to shear force than Angora meat, which in turn showed less resistance than Boer goat meat. Goat meat contained more collagen and the collagen was less soluble than that of sheep meat. The age of the various animals affected the cooking losses. Drip loss increased significantly with increasing age. Evaporation and total cooking losses also showed a tendency to increase with age. These were particularly noticeable in the M. semimembranosus cuts. The meat of animals of the A age group was juicier, more tender, contained less tissue less typical expressible residue, the flavour was more acceptable and the species flavour than that of the Band Cage groups. This was confirmed by the moisture and shear force resistance measurements. Meat of animals of the A age group contained more expressible moisture than meat from the B and C age groups. Meat from animals of the A age group also showed less resistance to shear force than that of the Band Cage groups. There was a significant decrease in collagen solubility of muscles with increasing age of the animal. This can be ascribed to the known increase in the number of crosslinks in the collagen fibrils that occur with increasing age of the animal, resulting in increased resistance to shearing and chewing of the meat. The protein and dry matter content of the cooked cuts increased, while the moisture and ash content decreased with an increase in age. Cooking yields of meat cuts were closely related to the fat codes of the various carcases. Higher drip, evaporation and total cooking losses were found as the fat codes of cuts increased. With increased fatness of carcases, the juiciness of the cooked cuts tended to decrease and the tenderness and species flavour to increase. The collagen solubility tended to increase and content to decrease with increased fatness. The latter may be ascribed to the increase of muscle fibre volume during the growth of the animal. fatness iv Hence, a decrease in the resistance to shear force with increased was found. With increasing level of fatness, the cuts contained less moisture, more fat and increased amounts of dry matter. This study confirms that goat meat is unique and should not be grouped with meat from comparable sheep having the same maturity and fatness levels with regard quality to palatability attributes. Significant differences exist between the characteristics of sheep on the one hand, and Angora and Boer goat meat on the other. The aroma of the sheep meat is more intense, it is more juicy, more tender, contains less fibrous tissue residue and the species flavour is more pronounced (typical) than that found in Angora and Boer goat meat. In general, the meat from goat carcases was found to be significantly less acceptable than that from sheep carcases, the Angora to a lesser extent, however, than the Boer goat. As was anticipated this study confirms the fact that the meat of younger animals is more juicy, more tender, contains less fibrous tissue residue during chewing and the species flavour is less typical than that of older animals. This was irrespective of the fact whether it was obtained from sheep, Angora or Boer goat. Significant differences in the palatability attributes were found with an increase in the fatness (fat codes) of the animals. With increasing fatness, the juiciness of the cooked cuts tended tc, decrease and the tenderness and species flavour to increase.