Óleo essencial de capim-limão (Cymbopogon flexuosus) na dieta de frangos e peixes: impacto no desempenho e qualidade da carne

Abstract

The aim of present work was to evaluate the effect of dietary supplementation with essential oil (EO) of lemongrass (Cymbopogon flexuosus) on productivity indicators and biochemical markers of broilers (Galus galus) and silver catfish (Rhamdia quelen), as well as to evaluate the quality and stability of the meat of these animals during frozen storage. One-day-old male Cobb chicks were fed control diet or diet supplemented with 0.25 mL of EO/kg for 20 days. EO increased body weight only in the 3rd week of supplementation but increased serum triglycerides and liver weight by 35% and 10%, respectively, and reduced serum globulins by 16%. Breast meat from animals treated with EO had no change in the proximate composition, but had higher proportion of palmitic acid. There was no change in the meat volatile compound profile but the taste acceptance was improved by EO diet. EO supplementation increased pH and thiobarbituric acid reactive substances (TBARS) values during meat storage at -18°C for 12 months, indicating that lipid stability during frozen storage was reduced by EO supplementation. The effect of feeding control diet or diet supplemented with microencapsulated lemongrass EO for 1 or 3 mL/kg during 20 days was evaluated in adult silver catfish. Productive performance, metabolic parameters, body composition and fillet quality were investigated. Total length, condition factor, weight gain, specific growth rate, hepatosomatic index, visceral fat content and fillet composition were not affected by EO supplementation. Plasma levels of total protein, globulin and triglycerides were reduced by supplementation with 1 mL/kg of EO. EO supplementation at 1 mL/kg increased carcass yield and protein deposition in the carcass but reduced the gonadosomatic index and fat deposition compared to the control group. In addition, 1 mL/kg increased feed intake compared to 3 mL/kg of EO. Dietary supplementation with EO did not affect the proximate composition, fatty acid composition or sensory acceptance of silver catfish fillets. However, during 12 months of frozen storage, fillets from fish treated with 3 mL/kg of EO had greater color and texture changes. In addition, supplementation with C. flexuosus EO was not able to prevent protein or lipid oxidative changes in fish fillets regardless of the dose used. These evidence suggest that the use of C. flexuosus EO in poultry feed is not recommended, whereas feed supplementation with 1 mL/kg of microencapsulated EO is recommended for silver catfish in the fattening stage, to increase the carcass yield and protein deposition in carcass.