46E-28 |
Antioxidant activity of hazelnut extracts containing phenolic compounds |
C. M. LIYANAPATHIRANA, Dept. of Biology, Memorial Univ. of Newfoundland, Saint John's, NF A1B 3X9, Canada and F. Shahidi, Department of Biochemistry, Memorial University of Newfoundland, St. John's, NF A1B 3X9, Canada. Phenolic compounds are commonly found in both edible and non-edible parts of plants and are known to have multiple biological effects. Nutritional epidemiology has also shown that nut consumption protects against cardiovascular diseases. The total phenolic content, free radical scavenging capacity and total antioxidant status (TAS) of edible and non-edible components {defatted kernel (DK), brown skin (BS), hard brown shell (HBS) and green hull (GH)} of hazelnut were examined. Crude hazelnut phenolics were extracted into aqueous ethanol and used following removal of the solvent. Total phenolic content of the extracts was determined spectrophotometrically according to Folin-Ciocalteu procedure. The antioxidant activity was evaluated using hydroxyl, peroxidase and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assays at 100 and 200 ppm phenolic levels. TAS of extracts was determined using trolox equivalent antioxidant capacity (TEAC) assay. Total phenolic content of the extracts varied from 38.3 to 503.1(4.8) mg per g of the crude extract; the lowest being for DK and the highest for BS. At 200 ppm phenolic level each fraction exhibited 94 to 100% scavenging capacity with each of the radicals tested except DK that showed only 38 and 77% of scavenging with DPPH and hydroxyl radicals, respectively. The lowest radical scavenging capacity was shown by DK in each instance. On the other hand, TAS of DK, BS, HBS and GH was 29, 132, 120 and 117 trolox equivalents for 2mg of the crude extract per mL. The results demonstrate strong antioxidant activity of hazelnut components and their potential health benefits in nutraceutical applications.
Session 46E, International
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