Determinação da atividade antioxidante de óleos de plantas amazônicas utilizando imagens digitais

Abstract

This study aims to determine the antioxidant activity of oils from Amazonian plants using digital images. In this work, a methodology based on digital imaging for determination of antioxidant activities of the oils seeks to demonstrate its viability for the purpose it is proposed to compare their results with well established methods such as UV-Vis spectrophotometry. The method used to determine the activities was to scavenging free radicals, DPPH (di (phenyl) - (2,4,6-trinitro-phenyl) imino-azônio). Tests with standard quercetin and samples were conducted in a methanol solution of DPPH with the spectrophotometric measurements at 517 nm then was made to capture images through the scanner with their treatment by the HSV color system. The antioxidant activities of samples and standards were determined for a sequestering capacity (SC) of 50% DPPH. The oils showed better antioxidant activities were Andiroba which required a concentration of 24.84 mg / mL, followed by Brazil-nut 25.84 mg / mL, copal 27.59 mg / mL and tucumã (pulp) 35, 65 mg / mL for the spectrophotometric method. DIB method for the oils showed better antioxidant activity were tucumã (almond) 34.94 mg / mL, Andiroba 35.30 mg / mL, cupuaçu 36.84 mg / mL and Brazil-nut 49.34 mg / mL . Although the results obtained by the two methods, as a rule, are discrepant, when subjected to statistical analysis by use of the paired t test two methods showed no significant differences for a confidence level of 95%.