Chemical, microbiological, and sensory parameters during the refrigerated storage of silver catfish (Rhamdia quelen) exposed in vivo to the essential oil of Lippia alba.

This study evaluated whether the essential oil of Lippia alba (EO) used as a sedative for fish transport would increase the stability of silver catfish during ice storage. Fish were transported (6 h) with water alone (control), 30 or 40 µL/L of EO in water. After transport, fish were slaughtered and stored in ice. Data on mesophilic and psychrotrophic bacteria counts during storage did not support the evidence for the antimicrobial activity of EO. However, fish treated with EO (30 and 40 µL/L) had delayed onset of rigor mortis, delayed increase of pH after 34 days of storage, and delayed peak of hypoxanthine formation and its degradation. In addition, the demerit sensory score of EO-treated fish (30 and 40 µL/L) was lower than that of controls along the storage. Thus, the use of EO as a sedative in the water used to transport silver catfish can delay the loss of freshness and the deterioration of whole fish stored in ice.