The effect of phosphate and bicarbonate on NMR relaxation properties in marinated poultry meat

NMR relaxometry has been successfully applied to study water distribution and properties in pork, poultry and rabbit meat. The most common ingredients used for processed meat products are salt and phosphates, however phosphate use in uncooked meat products is banned in several countries and overall its replacement is a major focus area for meat industry. This work was aimed at studying the effect of bicarbonate used as phosphate replacer on liquid absorption and water distribution in poultry meat. A total of 140 samples were obtained from an homogenous batch of broiler breast meat and subjected to vacuum tumbling with a 12% water/meat ratio using different combinations of NaCl (S, 1%), Na4O7P2 (P, 0.3%) and NaHCO3 (B, 0.3%): non-marinated (control, C), S, P, B, SP, SB and SBP. Proton transverse relaxation decay (T2) curves were registered after marination and subsequent cooking by means of NMR spectroscopy at 20 MHz. Also pH, colour (L*a*b*), marinade uptake and water holding capacity using standard methods were measured. The main results evidenced that, especially when combination of salts was employed, water gain following marination moved towards higher T2 the peak related to myofibrillar water in both raw (about 4%) and cooked (about 2%) meat with no significant differences among solutions containing P or B in combination with S. Overall SB and SPB treatments exhibited the best marination performances (marinade uptake and losses during cooking). In conclusion, this study showed that sodium bicarbonate in combination with sodium chloride was able to guarantee at least the same water distribution and properties in respect to phosphates. This can be exploited to develop processed poultry products with no added phosphates in order to match the request to avoid the nutritional drawbacks which have been recently evidenced in relation with the use of phosphates.