Phenolic compounds and antioxidant activity of Pecan [Carya illinoinensis (Wangenh.) C. Koch] kernel cake extracts obtained by sequential extraction

Abstract

The total phenolic and condensed tannin contents of different Pecan kernel cake extracts (ether, acetone, alcohol and distilled water) were estimated and their antioxidant activities were evaluated through ABTS, DPPH and ß-carotene/linoleic acid systems. Color variations of the Pecan kernel cake were determined through an instrumental analysis using the CIE Lab system. Significantly higher levels (p < 0.05) of total phenolics, condensed tannins and antioxidant activity measured through the ABTS and DPPH (30 min and 24 h) systems were observed for the acetone extract (16.4 mg GAE/g; 31.2 mg CE/g; 235.3 μmol TEAC/g and 68.6 and 100.3 mg TEAC/g, respectively). The oxidation inhibition percentage in the ß-carotene/linoleic acid system varied from 37.9 to 93.1%, with the acetone extract at 300 ppm showing significantly superior results. The samples with the greatest tendency to show red tones presented the highest levels of condensed tannins.

Keywords

• antioxidant activity
• carya illinoinensis
• oxidation
• pecan kernel cake
• phenolic compounds