Agriculture sector of Pakistan is crucial for the economy of the country, livestock constitutes major part of it. Livestock products like meat and milk are important source of protein for the human beings. With the rise in incomes and increasing urbanization, use of animal based protein source is increasing at a faster rate. Mutton in general and goat meat in particular is being preferred by the local consumers as well as by export destinations like Middle East. There are certain quality issues associated with goat meat like discoloration and toughening of meat. These problems are linked with age and sex of animal and processing factors like chilling. As the animal age, sex and chilling rate has significant effect on ultimate goat meat quality parameters like color, cooking loss and tenderness. So it is required to optimize age, sex and chilling rate in order to improve goat meat quality. Present study was designed to investigate the effect of age, sex and chilling regime of goat carcasses.
Animals were procured from Local animal market (mandi) and then slaughtered according to Halal standard method. After slaughtering, carcass were split into two halves longitudinally and one half for delayed and another for rapid chilling. Temperature and pH of the sirloin muscle were measured by inserting pH meter and food grade thermometer. For color determination Minolta® chroma meter was used and for tenderness determination texture analyzer was used.All the collected data was analyzed by using t-test under Complete Randomized Design and level of significance among different interaction were studied by using One Way ANOVA with the help of SAS 9.1. Results showed that,rapid chilling caused sudden fall in temperature but the rate of pH fall was slower than the delayed chilled carcass. After 2hour of slaughtering, rapidly chilled milk teeth animals had lower carcass temperature as compare to two teeth. While in case of sex, female goats had lower carcass temperature in contrast to male. Results revealed that age either
milk or twoteeth animals had non-significant effect on Warner Bratzler Shear Force (WBSF) values. Similarly color measurement also had no effect of age except lightness (L*), which was higher in milk teeth than two teeth animals. Animal sex had no effect on Warner Bratzler Shear Force (WBSF) and color values like lightness (L)*, redness (a*), yellowness (b*), chroma (C*) and hue angle (h). While sex have higher cooking loss % in male as compare to female. Chilling method directly related to the mean tenderness value.As, rapid chilling cause toughness of meat due to the difference in temperature and pH fall as compare to delayed chilling. In case of rapid chilling, mean Warner Bratzler Shear Force (WBSF) values were higher as compare to carcass which were subjected to delay chilling.
Based on the results of the present study, it has established fact that chilling has major effect on the quality of meat. Rapid chilling can lead to cold shortening of meat and as a result the end product could become tougher. While delayed chilling leads to more tender meat. As far as age of the animal is concerned, there is non-significant difference between milk teeth and two teeth goats. It is also common in Pakistan that consumers like to eat mutton from milk teeth and two teeth goats. However, mutton obtained from goats older than two teeth need investigation regarding meat quality. In the same way, exporters are exporting goat carcasses of milk and two teeth animals but the chilling method adopted by processors in not proper. It is common practice that due to shortage of time, processors do not allow the carcasses to stay for pre-chilling and put the carcasses in chillers directly. Ultimately the carcasses lead to cold shortening and consumers’ complaint about the tenderness of the meat. Secondly the age of the goat is directly linked with lightness of meat color, i.e. older animals have higher myoglobin content and this is the reason that older animals have dark colored meat.