Proximate composition of seeds and seed oils from melon ( Cucumis melo L.) cultivated in Bulgaria

The seeds of three varieties of melon (Cucumis melo L.) from Bulgaria were analyzed for their chemical composition and a detailed study of their lipids was carried out. Chemical composition values were as follows: fat content ranged from 41.6 to 44.5%, protein 34.4 to 39.8%, crude fiber 4.5 to 8.5%, carbohydrates 8.2 to 12.7%, soluble sugars 3.7 to 4.2%, and minerals 4.6 to 5.1%. The content of sterols, phospholipids, and tocopherols in the oils was 0.6, 0.7–1.7%, and 435–828 mg/kg, respectively. The major fatty acid in lipids was linoleic (51.1–58.5%), followed by oleic acid (24.8–25.6%). The trilinolein (31.3–32.2%), oleo dilinolein (31.0–34.0%), and palmitoyl dilinolein (14.9–22.3%) have represented 80.0% from the total triglyceride composition of the melon seeds oil. β-Sitosterol predominated in both free and esterified sterols, being, respectively, 52.9–70.8 and 50.4–58.4%. Phosphatidylinositol (24.4–33.9%), phosphatidylcholine (23.0–33.1%), and phosphatidylethanolamine (8.4–17.1%) were the main phospholipids. Palmitic acid (34.4–61.7%) was the major fatty acid of the phospholipids, followed by oleic acid (8.9–27.2%). Linoleic acid (32.7–39.1%) was the main component among the fatty acids of the sterol esters, followed by oleic acid (25.1–30.7%). In the tocopherol fraction of melon seed oils, the main component γ-tocopherol varied from 71.4 to 91.5%.