4-methyloctanoic acid and 4-methylnonanoic acid in goat meat as affected by castration, spaying and nutrition

Three studies were conducted to determine the physical characteristics and chemical composition of goat meat, determine the fatty acid profile of goat meat and evaluate the sensory characteristics as affected by sex, castration, spaying and feeding with concentrate. A total of 32 weanling grade goats were randomly distributed into 8 treatment groups in a 2x2x2 factorial design. In study 1, the water holding capacity, firmness and tenderness moisture content of goat meat were significantly increased by castration, spaying and concentrate supplementation. Crude protein content, ether extract, ash content were significantly affected by sex, type of animal and diet but not significant effect was observed for salt and cholesterol content and pH. In study 2, caproic, caprylic, capric, 4-methyloctanoic acid and 4-methylnonanoic acid content in goat meat were decreased significantly affected by sex, type of animal and diet. The concentration of 4-methyloctanoic acid and 4-methylnonanoic acid were significantly higher in male than in female. These five fatty acids were noted as the contributory factor of the goaty odor and flavor in goat meat. In study 3, the color, odor, off-flavor and tenderness for freshly cooked goat meat were not significantly affected by sex, type of animal and diet. Flavor, juiciness, saltiness, goatiness and general acceptability were significantly affected by sex, castration, spaying and concentrate supplementation. In freshly goat meat patties, the color, juiciness, goatiness and general acceptability were significantly affected by sex, type of animal and diet. Vacuum and aerobic packed patties from spayed fed with roughage only and stored at up to three weeks obtained the highest general acceptability scores. Total plate count of vacuum and aerobic packed significantly increased with the length of storage. Significant interactions were noted between sex, by type of animal by storage in vacuum packed patties and between type of animal by storage in aerobic packed patties. Total plate count was significantly affected by packaging method and the storage period of 25 days. The results of the study imply that physical characteristics, chemical composition and fatty acid profile of goat meat were affected by sex, castration, spaying and concentrate supplementation. The fatty acids caproic, caprylic, capric, 4-methyloctanoic and 4-methylnonanoic acid were proved to have their contributory effect in the development of goaty odor and flavor in goat meat. Vacuum and aerobic packed patties from castrates and spayed had the highest general acceptability.