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

Abstract

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%.