Avaliação do potencial antioxidante de extrato de alecrim na preservação de filés de tilápia do nilo defumados

Abstract

The Nile tilapia is a fish of great importance in world aquaculture , one of the species most suitable for intensive farming . This species is highly sought after by the consumer has important requirements when purchasing such as : white flesh and firm texture . Due to the high lipid content of the flesh of Nile tilapia, this deteriorates rapidly if not handled, transported and stored correctly. Smoking is a process commonly used for meat products, and aims to improve sensory and organoleptic properties of the product intended for human consumption. In view of the antioxidant present in the smoking process, such as aromatic compounds, this process benefits the meat increasing its useful life. On the other hand, smoking makes food contact surface conducive to the action of oxygen and the consequent formation of free radicals, which accelerates the redox reactions of fatty acids. The study aimed to evaluate the antioxidant potential of rosemary extract in inhibiting lipid oxidation of tilapia fillets smoked. Analyses Physico- chemical properties of fresh tilapia fillets, which were pH, lipids, color and water activity for fresh fillets, analysis of total antioxidant activity by FRAP and ABTS method and analysis of phenolic compounds in the extract and TBARS for fillet with rosemary smoked increased. The filet was fresh within the standards described in the literature, being 15.25% lipid, 6.1 for pH and water activity to 0.741. Regarding the antioxidant activity, the extracts were effective when antioxidant to quest with a value very close to comparing them to other authors (ABTS = 12.85 mM Trolox Eq / g ; FRAP = 36.73 mM Trolox equivalent / g phenolics = AGE/100 123.59 mg g dry extract). For lipid oxidation smoked fillets (TBARS) in 15 days, the values shown are high ( T1 = 5.42 ± 0.215 to T6 = 5.66 ± 12,688 a; T5 = 7.99 ± 0.008 nd , T4 = 10, 09 th ± 0.005 , 15.63 ± 0.001 T3 = second ), thus obtained a final product rather oxidized and can no longer be consumed.