Quality characteristics of meat refer to different attributes that determine its degree of acceptance by the consumer. These depend on different independent but interacting production and processing factors. They are broadly classified into pre-slaughter and post-slaughter factors.
Important factors affecting the basic composition and quality are given below:
1. Species:
Meat of different species differs in composition, postmortem glycolysis, tenderness, colour, flavour and functional characteristics. The colour intensity differences between species are primarily caused by differing concentrations of myoglobin. The beef has the highest concentration of myoglobin. Lamb is intermediate in colour and pork is lightest in colour.
2. Heredity:
Different breeds differ in growth potential and quality characteristics. Many physical properties of meat are greatly influenced by genetic factors. For example, colour and firmness of pork and beef are estimated to be approximately 30% inheritable. Marbling in pork is approximately 25% inheritable. Tenderness in beef may be up to 60% inheritable while tenderness in pork is only 30% inheritable. Improvements to the end quality of meat can be made by careful selection of livestock breeds and strains.
3. Sex:
Different levels of sex hormones generally cause variations in meat quality. Female animals have tendency to deposit more fat than males. Degree of tenderness also differs in male and females. Male animal usually produces darker meat than females. The meat of boars often has an unpleasant odour. This odour is most often noted during cooking and may go unnoticed after cooking.
4. Age:
Irrespective of species, breed or sex, the composition of muscles varies with increasing animal age, the degree of intra- and inter-molecular cross-linking between the polypeptide in collagen increases with increasing animal age. Thus, young animals produce more tender meat than old.
Fattening is also closely related to age of animals/birds. Meat flavour also intensifies with age. The flavour of meat of older animals, especially sheep, may be so intense that some find it to be objectionable. Animal age also causes darkening of meat due to increased levels of myoglobin.
5. Muscle Location and Activity:
Some muscles yield more tender meat than others. Muscles that are free to shorten during rigor mortis are generally less tender. Another factor affecting meat tenderness is the strength and usage of the muscle. With increase in muscular activity, connective tissue increases, which causes toughness? Muscular activity also affects composition of muscle tissue.
6. Nutritional Factors:
Quality and quantity of nutrients in feed and plane of nutrition also affect quality of meat. Certain feeding regimes and particular substances in the diet of livestock can affect the quality of meat. Starchy foods and sugars fed before slaughter can help restore depleted muscle glycogen levels to allow development of a normal postmortem pH. Abnormal flavours in sheep meat have been reported from lambs grazing on certain strains of clover and other legumes. An undesirable “grassy” flavour may result from compounds found in forage.
7. Managemental Factors:
Managemental factors like temperature and humidity also affect quality of meat. Uses of chemicals, growth promoters, antibiotics, hormones, etc. have influence on quality of meat in one way or other.
8. Pre-Slaughter Fasting:
Longer or shorter fasting period than the recommended, adversely affect quality of meat.
9. Method of Stunning and Killing:
Different slaughtering methods (Jhatka, Halal, Kosher, etc.) have different impact on quality of meat, e.g., Jhatka meat has good colour but shorter shelf life in comparison to Halal meat.
10. Chilling and Ageing:
Time and temperature of chilling effect rigor mortis development and quality of meat.