Characteristics and antioxidant activities of seed oil from okra (Abelmoschus esculentus L.)

To investigate the potential functional properties and added value of okra seed oil and provide a scientific basis for further industrial development and production of okra seed oil, its fatty acid profile, total phenolic, fat-soluble vitamin composition, mineral element composition, and antioxidant activities were examined in this study. Also, correlations between bioactive components and the antioxidant activities of okra seed oil were explored. The study results show that okra seed oil contains 12 types of fatty acids, 65.22% of which are unsaturated acids, and among these unsaturated acids, linoleic acid (43%) and oleic acid (20.16%) are two dominant acid types. Compared with walnut oil and peanut oil, okra seed oil contains relatively high total phenols, fat-soluble vitamins, and a variety of essential mineral nutrients, with a total phenolic content (TPC) of 959.65 mu g/mL, a total tocopherol content of 742.71 mu g/mL, a vitamin A content of 0.0017 mu g/100 mL, a vitamin D content of 1.44 mu g/100 mL, and a vitamin K-1 content of 52.54 ng/100 mg. Also, okra seed oil exhibits better scavenging activities on hydroxyl (IC50 = 0.50 mg/mL) and ammonium salt (ABTS) free radicals (IC50 = 6.46 mg/mL) and certain reducing power (IC50 = 17.22 mg/mL) at the same concentration. The scavenging activities of okra seed oil on hydroxyl radicals and ABTS radicals, as well as its reducing power, are significantly correlated with its contents of total phenol, total tocopherol, alpha-tocopherol, and gamma-tocopherol (p < .01). These results show that okra seed oil is rich in bioactive substances, thus presenting great nutritional potential.