Quality Attributes in Shrimp Treated with Polyphosphate after Thawing and Cooking: A Study Using Physicochemical Analytical Methods and Low-Field 1H NMR

The effects of polyphosphate on parameters of quality in shrimp (after thawing and cooking) were investigated using physicochemical analytical methods and low-field nuclear magnetic resonance (LF H-1 NMR) spectroscopy. The NMR data were treated by bi-exponential fitting and compared with the physicochemical data. The physicochemical parameters demonstrated that treatments with different concentrations of sodium tripolyphosphate and different time exposures influenced parameters such as cook loss, moisture, pH, color and texture. These differences were reflected in the transverse relaxation (T-2) data. Bi-exponential fitting of the T-2 resulted in the observation of two water populations in all samples, T-21 and T-22, with relaxation times in the ranges of 24-47 and 63-120ms, respectively. Pronounced changes in the T-21 and T-22 relaxation data were observed during the different treatments, with polyphosphate revealing changes in water properties. Good linear correlations were observed between the T-2 parameters and physicochemical data.