Abstract:

Objective: To evaluate the fatty acid composition and total polyphenol contents of cold-pressed seed oils from
four different grape varieties and assay their in vitro antioxidant activity. Methods: The fatty acid composition was measured
by gas chromatography with flame ionization detection (GC-FID). The content of polyphenols was determined using the
Folin-Ciocalteau method and the in vitro antioxidant activity was tested by 1,1-diphenyl-2-picryhydrazyl (DPPH)
radical scavenging, 2,2’-azinobis-3-ethylbenzthi azoline-6-sulfonic acid (ABTS) radical scavenging and Fenton
reaction methods. Results: The most abundant fatty acid in all cold-pressed grape seed oils was linoleic acid (72.77%–
77.36%) and the content of unsaturated fatty acids ranged from 88.12% to 91.06%. Total polyphenols ranged from 60.77
to 100.53 μg GAE/g and the order of total polyphenol contents in grape seed oils from different grape varieties was Ecolly >
Beibinghong > Meili > Carbernet Sauvignon. All clod-pressed grape seed oils had strong scavenging activity against
DPPH, ABTS and hydroxyl free radicals in a dose-dependent manner, with IC50 values ranging from 10.19 to
13.82 mg/mL, from 11.62 to 19.25 mg/mL, and from 13.18 to 27.08 U/mL, respectively. The IC50 value of total
antioxidant capacity ranged from 1.08 to 3.68 U/mL. The order of in vitro antioxidant activity of cold-pressed grape
seed oils was Ecolly > Beibinghong > Meili > Carbernet Sauvignon.

Key words: cold-pressed grape seed oil, polyphenols, in vitro antioxidant activity