Abstract

In this study, the antioxidant properties and the polyphenolic contents of raw and cooked pinhão seeds were evaluated. Four methods were used to evaluate the antioxidant activity: 1,1-diphenyl-2-picrylhydrazyl free radical scavenging (DPPH), 2,2’-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid scavenging (ABTS), ferrous ions chelating activity and lipid peroxidation inhibition (LPO). The EC₅₀ values (extract concentration producing 50% antioxidant effect), in μg/ml extract for raw and cooked extracts yielded respectively: DPPH, 870.7±30.8 and 112.6±5.4; ABTS, 170.7±7.8 and 52.1±2.1; ferrous ions chelating activity, 1,719±84.8 and 761±77.1; and LPO, 55.9±4.7 and 53.8±4.5. The improvement in the antioxidant activity in the cooked seeds can be attributed to the migration of polyphenolic compounds from coat to seed during cooking (5.92 ± 0.09 μg/mg and 24.06 ± 1.3 μg/mg in the raw and cooked seed extracts, respectively). Both raw and cooked seeds presented elevated amounts of catechin, 17.49±0.06 and 21.08±0.09 mg/100 g of seed, respectively.

Key words: Antioxidant activity, Araucaria angustifolia, catechin, food processing,pinhão seed, polyphenolics.