Essential oil composition and total phenolic compounds of naked and normal seed types of different accessions of Cucurbita pepo L. in Iran

Cucurbita pepo var. styriaca is known as a medicinal crop among other cucurbits and has been cultivated around many decades in some parts of Iran by local farmers. The present study was conducted on 8 accessions of C. pepo seed from various planting zones. All collected seeds were planted in Horticultural Science Research Field of University of Tehran in three replications with two observations in each replicate based on randomized complete block design. Seed characteristics and phytochemical composition were analyzed after fruit ripening. The result of variance analysis showed that all of the studied characteristics had significant differences among accessions. Gorgan accession (193 gr) and Mashhad accession (102 gr) had the highest and lowest seed weight, respectively which had seed coat in comparison with naked seed types. Among naked seeds, Shahroud accession revealed higher seed weight (148 g). Maximum oleic acid content, an unsaturated fatty acid (vital and important fatty acids), was for Esfahan accession as naked seed. The results showed that maximum total phenolic compound was related to Qom accession with 4 mg GAE/kg and Khomein accession as naked seed type had maximum antioxidant content. Although naked seed is known as medicinal cucurbits because of high amount of un-saturated fatty acid, this study demonstrated that other cucurbits like Chalous accession with normal seeds also had high amount of unsaturated fatty acid.