Water-holding capacity of meat

The water holding capacity of muscle tissue soon after slaughter is high because the muscle 

The meat of bulls ( 5 years) and oxen (2-3 years) is of little economic importance. The average amount of waste from slaughterhouse oxen is 40-55% that from cows, 42-66%. Beef carcasses are hung for 4-8 days before being cut up for soup meat, and 10-14 days for roasts or steaks. 

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When an animal or plant is killed, its cells become more permeable to moisture as pointed out by Potter [54]. When the tissue is blanched or cooked, the cells may become still more permeable to moisture. Generally, cooked vegetable, meat, or fish dried more easily than their fresh counterparts, provided cooking does not cause excessive shrinkage or toughening [54]. Cooking also results in a decrease in water-holding capacity of meat products [83]. 

The changes in water holding capacity of meat resulting from ATP transition to IMP are dealt with in Section 12.5. Unlike purines, pyrimidine nucleotide content in muscle is very low (Table 12.9). 

Wierbicki, E., and F.E. Deatherage. 1958. Determination of water-holding capacity of fresh meats. J. Agr. Food Chem. 6 387-392. 

Hydration. The ability of proteins to bind and hold water without syner-esis is critical in many foods, e.g. comminuted meat products. Although the caseins are relatively hydrophobic, they bind c. 2g H20g protein, which is typical of proteins. Hydration increases with increasing pH and is relatively independent of NaCl concentration, which is especially important in the efficacy of casein in meat-based products. The water-holding capacity of sodium caseinate is higher than that of calcium caseinate or micellar casein. 

The water holding capacity of frozen meat increases as the freezing temperature decreases. 

In order to extend or improve the water holding capacity of processed meat, the product may... 

Meat quality is most affected by the length of the fattening period, meat from older animals is tighter, darker, more aromatic and has lower water-holding capacity. 

The proteins of egg white are readily denatured by heat and by surface forces when egg white is whipped to a foam. Meat proteins are denatured in the temperature range 57 to 75°C, which has a profound effect on texture, water holding capacity, and shrinkage. 

The amount of stroma proteins is less in fish muscles (3-5%) than it is In beef or rabbit muscles (15-18%). This may explain why raw fish fillets are acceptable in Japanese dishes, whereas beef, rabbit and pork are rarely served raw. According to Fennema et al. (9.), tenderness is primarily related to collagen content, while toughness and water-holding capacity are associated with the myofibrillar proteins. Many papers on cooked meat mention both tenderness and toughness, while those on cooked fish note the problems of toughness rather than tenderness. This also might be related to the difference in content of the stroma proteins. 

Power ultrasound has also been found to be effective in the extraction of protein from meat [58]. Ultrasound disrupts the meat myofibrils and this releases a sticky exudate which binds the meat together. The binding strength, water holding capacity, product color, and yields were examined after treatment either with salt tumbling, sonication, or both. Samples which received both salt treatment and sonication were superior in all qualities. Similar results were obtained from a study of the effect of sonication on cured rolled ham [59]. Ultrasonic treatment enhanced the extraction of myofibrillar proteins leading to an increase in the strength of the reformed meat. 

Mineral elements are in enzymatic complexes and other structures that play an important biochemical role. They can affect the technological properties of meat, e.g., water-holding capacity, as well as the sensory characteristics. Meat is also a good source of B group vitamins. 

Inside the muscle fiber there is also a cytoskeleton — the protein structures assuring the integrity of muscle cells. Cytoskeletal proteins such as titin and nebulin are located in myofibrils and anchored in the Z line. Desmin is made up of costamers, which connect the myofibrils vinculin connects myofibrils and sarcolemma. Postmortem changes in cytoskeletal proteins probably play a role in the improvement of meat functional properties, especially its tenderness and water-holding capacity. 

For better characterization and understanding of meat characteristics, the potential of NMR spectroscopy and imaging has been illustrated." Authors demonstrate the energy metabolites in muscle, fatty acid components of animal fat, a quantitative measurement of parameters closely correlated with meat properties such as pH, cooking yield and water holding capacity at each point of an NMR imaging and so on. It is concluded that NMR is a powerful tool for meat research in comparison with other less expensive techniques. 

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