Physicochemical and antioxidant characteristics of gingerbread plum (Neocarya macrophylla) kernel oils

Abstract

This study examined the physicochemical characteristics and antioxidant activities of oils extracted from gingerbread plum kernels grown in two different areas (Niger and Guinea). The oil contents were found to be significantly different (P ≤ 0.05); 56% and 60% for gingerbread plum kernels originated from Niger (GPKN) and guinea (GPKG), respectively. GPKG showed the highest levels for physical parameters such as iodine, saponification, free fatty acid, acid and peroxide values when compared with GPKN. The major monounsaturated fatty acid in both GPKN and GPKG was oleic acid (42.46 and 41.43%, respectively) while the polyunsaturated fatty acids consisted of linoleic and arachidonic acid. Arachidonic acid was at higher levels (17.67 and 21.72% in GPKN and GPKG, respectively) than those in common vegetable oils. Results from antioxidant activity essays showed that GPKG is more active than GPKN in DPPH radical scavenging, β-carotene and phenolic contents while GPKN showed the highest values for reducing power and flavonoid. Of the 11 sterol compounds found in this study, 24-hydroxy-24-methyl cholesterol, clerosterol and sitosterol accounted for 68.5% and 66.33% in GPKN and GPKG, respectively. Finally, all tocopherol vitamers (except γ-tocopherol) were present in GPKN and GPKG with α-tocopherol being the main element in both samples.

Keywords

• antioxidant activity
• fatty acid profile
• gingerbread plum kernel
• oil indices
• sterols
• tocopherols