Correlation between impedance and freshness indicators of silver carp (Hypophthalmichthys molitrix) during 0 ℃ storage

The objective of the present work was to investigate the correlation bewteen impedance and freshness indicators of silvercarp (Hypophthalmichthys molitrix) during 0℃ storage and establish a rapid method for measuring freshness of freshwater fish.We determined the freshness indicators (total aerobic account, K value, juice loss, sensory score) and impedance change ratio (Q value) to analyze their correlation. Results reveal that the total aerobic count, K value and juice loss increased whileQ value and sensory score decreased with storage time. On the 15th day, the total aerobic count, K value, juice loss, sensory score and Q value were (6.850.07) log cfug-1, (63.971.93)%, (6.260.01)%, 10.01.4 and (22.922.60)%, respectively, indicating that the fillets had lost edible value. The correlation coefficient between the Q value and total aerobic count, K value, juice loss, sensoryscore were 0.972, 0.976, 0.945 and 0.984, respectively (P0.01). Therefore, Q value is a fast and nondestructive indicator to estimate the freshness of silver carp fillets during 0 ℃ storage.