Industrial dry electro-stunning followed by chilling and decapitation as a slaughter method in Claresse (Heteroclarias sp.) and African catfish (Clarius gariepinus)

This study evaluated the industrial application of dry electro-stunning for Claresse® and African catfish via monitoring of brain and heart activities, behavioral responses to noxious stimuli and meat quality. Dry electro-stunning (150 V, AC + DC, 100 Hz) of Claresse® for 0.7 ± 0.2 s (mean ± SD) resulted in unconsciousness for 48 ± 15 s, fulfilling the welfare requirements for obtaining pre-slaughter unconsciousness in less than 1 s. Current input for 5.2 ± 0.5 s with a measured current of 0.57 ± 0.16 A followed by chilling, resulted in prolonged unconsciousness for 124 ± 20 s in Claresse®. Loss of behavioral responses to noxious stimuli and then death within 5 min in 9 out of 10 African catfish resulted from stunning for 9.1 ± 0.4 s (0.91 ± 0.18 A) followed by decapitation. The meat quality did not reveal any difference in color between electro-stunned (0.76 A, 150 V, AC + DC for 15 s) and chilled-only Claresse®. Although flesh acidification was significantly higher in the stunned group on the day of the experiment, after 24 h the groups showed similar pH changes for the next six days. We conclude that dry electro-stunning (150 V, AC + DC) followed by chilling and decapitation is a reliable method for industrial pre-slaughter unconsciousness of Claresse® and African catfish and stunning (150 V, AC + DC) leaves no significant effect on flesh quality of Claresse® compared to chilling method.