Purine content in grass shrimp during storage as related to freshness

In grass shrimp (Penaeus monodon), the combined total content of the uricogenic bases adenine (Ade) and hypoxanthine (Hyp) decreased gradually during storage. Whether stored at 5 degrees C or at room temperature (22 degrees C), a negative regression of log Ade and a positive regression of the Kp value (Hyp/Ade) were observed. Volatile basic nitrogen (VBN) increased during storage at 5 degrees C and 22 degrees C, Correlations between the content of log Ade and VBN at 5 degrees C and 22 degrees C were -0.9248 (p < 0.01) and -0.8139 (p < 0.05, while those between the Kp value and VBN were 0.9557 (p < 0.001) and 0.8197 (p < 0.05), respectively. At the point where the shrimp would remain acceptable, the upper limits of Kp were 1.42 and 1.29 for storage at 5 degrees C and 22 degrees C, respectively; the corresponding lower limits of Ade were 18.72 and 20.42 mu mole/g dry wt.