Effects of Phosphates Treatments on Water Molecules in Refrigeration Yak Meat

In this study, the LF-NMR and PCA were used to investigate the effects of three phosphates (sodium pyrophosphate, SPD; sodium hexametaphosphate, SHMP and sodium tripolyphosphate, STPP) on the water molecules of yak meat stored in low temperatures for different time.The results show that, after 24 h treatment at 4 ℃, bound water and free water are both contained in yak meat.However, after 24 h freezing treatments at -20 or -70 ℃, the content of free water decreases significantly (P < 0.05) as well as the bound water is not detected in yak meat.The yak meat is cured in three kind of phosphates for 24 h respectively and the ability of water retention is that, sodium tripolyphosphate is strongest and sodium hexametaphosphate is stronger.When sodium pyrophosphate, sodium tripolyphosphate and sodium hexameta phosphate were added in the range of 0.36%-0.41%, 0.30%-0.45% and 0.35% respectively, the water retention of yak meat was the best.The principal component analysis results confirm that yak meat treated with phosphates, has a significant effect on water retention, and there is a significant difference between different additives and different content of the same additive.