P-31 NMR analysis of chicken breast meat vacuum tumbled with NaCl and various phosphates

The hydrolysis of several commercially used phosphates was studied in chick en breast meat marinated and tumbled in 70 g kg(-1) NaCl and 12 g kg(-1) of either disodiuum pyrophosphate (DSPP), tetrasodium pyrophosphate (TSPP), t etrapotassium pyrophosphate (TKPP), sodium tripolyphosphate (STPP) or glass phosphate. After treatment, intact muscle was ground in the presence of ED TA-Na-2 to prevent further enzymatic breakdown of phosphates. TSPP and TKPP were fully hydrolysed within 1.25 h, STPP within 3.25 h, DSPP within 6 h a nd glass phosphate within 24 h. DSPP lowered the muscle pH from 5.97 to 5.6 0, while TSPP and TKPP increased the pH to 6.10 and 6.19 respectively. Base d on PP chemical shifts, the pH was found to increase with time. No evidenc e of tripolyphosphate (TPP) in the STPP-treated samples was found, suggesti ng that it had already been hydrolysed to pyrophosphate (PP) or monophospha te (Pi) during treatment. PP hydrolysis occurred at about the same rate as Pi production in STPP-treated samples. Pi production in meat treated with g lass phosphate was relatively slow, indicating a lack of muscle enzymes cap able of breaking down long-chain phosphates. Late production of Pi after de pletion of oligophosphate was attributed to hydrolysis of cellular phosphat es. (C) 2001 Society of Chemical industry.