Influência do uso de óleo essencial de eugenol e de manjericão (Ocimum basilicum) na água de transporte pré-abate de tilápias criadas pela agricultura familiar

Abstract

Trying to offer animal welfare within the culture systems, which are more and more technified, the tilapiculture within the family agriculture is concerned in producing competitive products in the market with quality respecting the current laws. The objective of this study was to analyze the effect of two natural anesthetics on the quality of Nile tilapia meat when added to the transport water, in vivo, from the farm to the slaughterhouse and if the way of farming in this familiar system would present differences in the final product. For this purpose, a total of 100 adult fish, with a mean weight of 816.36 ±1.42 g, were distributed in five treatments: N: fish not transported; C: fish transported with water only (control); A: fish transported with water + anesthetic vehicle (ethanol 36µL L-1); E: fish transported with water + eugenol (20µLL-1) anesthetic vehicle; and M: fish transported with water + essential oil of Ocimum basilicum (20µL L-1 anesthetic vehicle). The fillets of 20 fish per treatment were collected to evaluate meat quality parameters. As a result, the quality of the transport water was not affected (p>0.05) during transportation between treatments, but the pH value was 4.59. There was no effect of the treatments when the colorimetry referring to yellow (b*) and luminosity (L*), shear force and water retention capacity were evaluated. For the colorimetry red on the viscera side (a*v) and red on the skin side (a*p), the highest values were determined for the fillets of treatments A and N, respectively. The pH of the fillets from fish transported with the anesthetics under study (E and M) maintained higher values. The fillets from animals in treatment N presented the lowest average percentage loss by thawing, while the highest loss by dripping was observed in treatment A, with high values, possibly due to the slow freezing method. In the chemical-bromatological composition, the averages for mineral matter (MM) showed significant difference in treatment M, the other parameters were within the normal values for the species. The fatty acid profiles were within the values for the species. The treatments did not show significant differences (p<0.05) in lipids. It was possible to verify that the natural anesthetics exhibited sedative capacity and did not cause damage, but did not contain typical physiological alterations caused by transport stress in Nile tilapia fillets, and the family farm form of farming offered a product with nutritional values favorable for food consumption.