Stability of frozen fillets from silver catfish anesthetized with essential oil ofLippia albaprior to electrical stunning or hypothermia

Abstract

The effects of anesthesia with essential oil (EO) of L. alba prior to electrical stunning or hypothermia were evaluated on the stability of silver catfish fillets during frozen storage. Electrically stunned fish had the greatest increase in lipid oxidation along the storage and previous anesthesia with EO potentialized this effect. Fish stunned by hypothermia with no previous anesthesia had higher lipid oxidation in the flesh immediately after slaughtering, which probably contributed to accelerate protein oxidation along the storage. Fish stunned by hypothermia had the highest springiness value by the end of storage and the highest changes in instrumental color along the storage, whereas electrically stunned fish had delayed protein oxidation and smaller color and texture changes during frozen storage. Thus, hypothermia induced greatest changes in physico‐chemical markers and previous anesthesia with the EO of L. alba did not prevent these changes and did potentialize lipid oxidation induced by electrical stunning. Practical applications There is a growing interest for natural anesthetics in commercial aquaculture and essential oils have been lately used with this purpose for fish husbandry and management. The use of natural anesthetics in pre‐slaughter steps, however, has been scarcely investigated. Stressful procedures during pre‐slaughter and slaughter steps can adversely affect fish flesh properties and the association of anesthetics with other stunning or killing methods could be an alternative to reduce fish stress and assure flesh quality. Our study, however, revealed that fillet stability during frozen storage is not improved by fish anesthesia with essential oil prior to hypothermia or electrical stunning. In addition, we also revealed that electrical stunning yielded greater fillet stability during frozen storage compared with hypothermia. These results are relevant in the search of humane fish stunning methods that provide the greatest flesh quality and stability.

Unconsciousness assessment through electroencephalography (EEG), in the process of stunning, for electronarcosis, percussion and anaesthesia for humane slaughter of Nile tilapia

“…Therefore, the use of Ocimum americanum and Lippia alba essential oils as preslaughter anaesthesia causes no decrease in the sensory quality of the Nile tilapia fillets and may thus be used as an alternative to the use of hypothermia for the pre-slaughter handling of fish in Brazil. This and other studies from Brazilian research groups Veit et al, 2016) could support changes in the regulations for the humane slaughter of fish in Brazil.…”

“…Studies on the use of natural anaesthetics prior to fish slaughter have increased in recent years, mainly the use of essential oils from the plants Lippia alba, Ocimum americanum and Aloysia triphylla, which do not show any negative effects on the aroma and flavour of the fish fillets (HOHLENWERGER et al, 2016;TEIXEIRA et al, 2016;VEIT et al, 2016 or cause aversion to the fish (BANDEIRA-JUNIOR et al, 2018), thus appearing as a humane alternative for fish slaughter.…”

Essential oils biological activity of the Lippia alba (Verbenaceae) shrub

“…In aquiculture, for L. alba essential oils, chemotype I has reported promising results, given their sedative effect on Rhamdia quelen (20-40 μL/L) (Salbego et al, 2017b;Veeck et al, 2018); anesthetic effect on Litopenaeus vannamei (> 30 μL/L) (Parodi et al, 2012), Colossoma macropomum (62,5-375 μL/L) (Batista et al, 2018), Echinometra lucunter (150 μL/L) (Simões et al, 2017), Rhamdia quelen (20 and 150-450 μL/L) (Cunha et al, 2010;Toni et al, 2014;Veit et al, 2017;Salbego et al, 2017b), Argyrosomus regius (200 μL/L) (Cárdenas et al, 2016), Serrasalmus rombeus (50-200 μL/L) (Almeida, Heinzmann, Val, & Baldisserotto, 2018), Sparus aurata (100-300 μL/L) (Toni et al, 2015); and reduce stress in Rhamdia quelen (10 -40 μL/L) (Azambuja et al, 2011;Veeck et al, 2013), Oreochromis niloticus (20 μL/L) (Hohlenwerger et al, 2017), Litopenaeus vannamei (> 30 μL/L) (Parodi et al, 2012), Echinometra lucunter (150 μL/L) (Simões et al, 2017), and tambacu hybrids (Piaractus mesopotamicus × Colossoma macropomum) (200 μL/L) (Sena et al, 2016).…”

<b>Supplementation with microencapsulated lemongrass essential oil improves protein deposition and carcass yield in silver catfish (<i>Rhamdia quelen</i>)

“…EOs have also been prospected for use as anaesthetic and sedative for fish, and have been shown to reduce the stress during transportation (Parodi et al, 2012;Salbego et al, 2017) and increase the shelf-life of refrigerated and frozen fish (Veeck et al, 2013;Daniel et al, 2014;2016;Veit et al, 2016).…”