Water absorption and interaction with meat proteins during marination

Water absorption of meat is improved by the used of solutions of various salts. These solutions have been optimized to 7% salt, 1.76% Sodium tripolyphosphate and a combination of both the salt and the phosphate. Studies of sections of meat under confocal scanning laser microscopy (CSLM) showed different zones of absorption depending on the salts used, confirming their operating by different mechanisms. The moisture exuded under different levels of compression (50%, 75% and 95%) and subsequent analysis by SDS-PAGE gels indicated different salts enhanced extraction of actin or myosin, the major myofibrilar proteins. Study of these marinated meats by Nuclear Magnetic Resonance (NMR) methods including spin-spin relaxation time; longitudinal relaxation time and diffusion coefficient did not clearly establish which method was optimum for an non-invasive study of water in the meats. Correlations were attempted between these values and various physical properties including weight gain after marination (“pickup”), weight loss after cooking (“cookloss”), and Warner-Bratzler shear values for cooked and raw meat. Confocal scanning laser microscopy was used to study the permeability of broiler breasts after marination with salt, phosphate and a combination of salt and phosphate solutions under tumbling vacuum marination. Chicken breasts were vacuum sealed in bags with 7% salt, 1.76% sodium tripolyphosphate (TPP) or both salt and sodium tripolyphosphate combined. A 1% fluorescein dye was added and the bags were tumbled for 30 minutes and let stand at 3°C for three days. It was observed that samples treated with salt only had a distinct layer about 50 um deep at the surface, while those treated with phosphate showed a more typical diffusion layer extending about 2000 um deep into the meat. The combination of salt and phosphate showed both a distinct layer and the deep diffusion pattern. This confirms the theory of Offer and Trinick (1983) that the different salts operate by different mechanisms and this information may help further the understanding of the process of marination.