Proximate and lipid composition of cowpea (Vigna unguiculata L.) cultivated in Bulgaria

• Chemical composition of cowpea seeds from IPGR collection in Bulgaria was analyzed.
• Fatty acid, sterol, tocopherol and phospholipid composition of oils was analyzed.
• Cowpea seeds are a good source of bio-active compounds.
• High nutritive values of the studied Vigna unguiculata accessions were established.
• Cowpea seeds are an alternative source of food for the future in Bulgaria.

The seeds of four accessions of cowpea (Vigna unguiculata L.) from the collection of the Institute of Plant Genetic Resources, Sadovo, Bulgaria were analyzed for their chemical composition and a detailed study of their lipids was carried out. Chemical composition values were as follows: protein content ranged from 22.5 to 25.6%, starch 28.3 to 36.2%, fat 1.3 to 1.9%, insoluble fiber 1.7 to 3.0% and minerals 3.2 to 3.7%. The oil content was relatively low, but an extremely high content of biologically active compounds (tocopherols in the oils range from 3838 to 11,475 mg/kg, phospholipids 12.2 to 27.4%) was noted. In oils from seeds of cowpea palmitic (35.1–47.1%) and linoleic acid (21.7–30.9%) dominated, followed by linolenic (7.3–16.8%) and oleic acid (6.9–10.6%). The main component in sterols composition was stigmasterol (42.1–43.3%), followed by β-sitosterol (27.6–39.5%). In the tocopherol fraction of oils from seeds of cowpea the main component γ-tocopherol varied from 44.0 to 66.6%, followed by δ-tocopherol (30.3–52.8%). Phospholipids in oils and seeds of various accessions of cowpea had similar qualitative and quantitative composition. Phosphatidylcholine was predominant – 34.5–46.0% of total phospholipids.