Chemicals
The refined soybean seed oil was obtained by a local oil refining
factory (Aliagolestan Co., Gorgan, Iran). Antioxidant compounds
including gallic acid, methyl gallate, propyl gallate, octyl gallate,
dodecyl gallate, and stearyl gallate of analytical grade (Fig. 1) were
supplied from Sigma-Aldrich (St. Louis, MO). All the other solvents and
chemicals applied in this research were purchased from Sigma-Aldrich
(St. Louis, MO) and Merck (Darmstadt, Germany).