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Bioactive Compounds, Antioxidant Activities and Heat Stability of Corn Oil Enriched with Tunisian Citrus aurantium L. Peel Extract
Author(s) -
JabriKaroui Iness,
Marzouk Brahim
Publication year - 2014
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/s11746-014-2485-3
Subject(s) - chemistry , dpph , antioxidant , food science , orange (colour) , limonene , corn oil , aroma , organic chemistry , essential oil
This study was designed to examine physicochemical composition, antioxidant activities and heat stability of corn oil enriched with bitter orange peel. Volatile compounds composition of corn oil flavored with Citrus aurantium peel was investigated. Flavored oil total aroma content (2.6 mg/mg oil) was mainly represented by monoterpene hydrocarbons and limonene was the major one (2.49 mg/mg oil). Flavored oil methanolic extract was characterized by total phenol content of 1.22 mg GAE/kg. Chlorogenic, ferulic and p ‐coumaric acids were the major phenolic components of the flavored oil extract (34.33, 30.24 and 19.39 %, respectively). It was also characterized by a higher chlorophylls and carotenoids contents than the refined one. Antioxidant activities of methanolic extracts of both samples were determined using four assays: DPPH, reducing power, β‐carotene bleaching and metal chelating tests. In β‐carotene bleaching and DPPH radical scavenging assays, flavored oil methanolic extract showed higher activities than the control. It was characterized by a total antioxidant activity of 4.08 mg GAE/kg and an EC 50 value of 3.14 mg/mg oil. Its concentration providing 50 % inhibition (IC 50 ) was 0.53 mg/mg oil in the DPPH test and 4.08 mg/mg oil in the β‐carotene bleaching test. However, refined corn extract showed significantly lower antioxidant activities ( p < 0.05). Results of the oxidative stability index showed bitter orange peel effectiveness against thermal oxidation based on the increased induction time observed in flavored oil (5.95).