title: Determination and characterization of kernel biochemical composition and functional compounds of Persian walnut oil.
abstract: Kernel chemical composition and fatty acids profile of three walnut cultivars (Toyserkan, Chaboksar and Karaj) was analyzed. Some physicochemical properties, total phenolics content (TPC), ortho-diphenols content (ODC) and total tocopherol concentration (TTC) of extracted oils from the walnuts were also determined. The antioxidant activity of oil was measured by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity and β-carotene bleaching assays. The analysis of chemical composition revealed that protein and dietary fiber was highest in Toyserkan cultivar. Phosphorus was the most abundant element in the walnut kernels, followed by potassium, magnesium and calcium. The linoleic acid and linolenic contents ranged from 50.15% to 51.36% and 10.48% to 12.04%, respectively. Also, the results demonstrated that acid value, saponification value and viscosity of extracted oil had significantly varied between all cultivars. The extracted oil from Chaboksar cultivar illustrated more hydro peroxides and secondary products than those obtained from other cultivars. A positive correlation was found between Rancimat values and oleic acid content (r = 0.60), but considerably negative correlation with TTC (r = -0.81) and TPC (r = -0.92). The relationship between percentage of remaining DPPH radical and β-carotene of walnut oils showed high correlation among three selected cultivars (r = -0.94 to -0.97).
authors.affiliation: Department of Food science, Engineering and Technology, Faculty of Agricultural Engineering and Technology, University of Tehran, P.O. Box 4111, Karaj, 31587-77871 Iran.
authors.forename: Seyed Mohammad Taghi
authors.initials: SM
authors.lastname: Gharibzahedi
authors.affiliation: Department of Food science, Engineering and Technology, Faculty of Agricultural Engineering and Technology, University of Tehran, P.O. Box 4111, Karaj, 31587-77871 Iran.
authors.forename: Seyed Mohammad
authors.initials: SM
authors.lastname: Mousavi
authors.affiliation: Department of Food science, Engineering and Technology, Faculty of Agricultural Engineering and Technology, University of Tehran, P.O. Box 4111, Karaj, 31587-77871 Iran.
authors.forename: Manouchehr
authors.initials: M
authors.lastname: Hamedi
authors.affiliation: Department of Food science, Engineering and Technology, Faculty of Agricultural Engineering and Technology, University of Tehran, P.O. Box 4111, Karaj, 31587-77871 Iran.
authors.forename: Faramarz
authors.initials: F
authors.lastname: Khodaiyan
keywords: Antioxidant activity; Fatty acid profile; Juglans regia L.; Mineral content; Oil analysis; Phenolic compounds; Physicochemical properties; Proximate composition