title: Optimization of hull-less pumpkin seed roasting conditions using response surface methodology.
abstract: Response surface methodology (RSM) was applied to optimize hull-less pumpkin seed roasting conditions before seed pressing to maximize the biochemical composition and antioxidant capacity of the virgin pumpkin oils obtained using a hydraulic press. Hull-less pumpkin seeds were roasted for various lengths of time (30 to 70 min) at various roasting temperatures (90 to 130 °C), resulting in 9 different oil samples, while the responses were phospholipids content, total phenols content, α- and γ-tocopherols, and antioxidative activity [by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free-radical assay]. Mathematical models have shown that roasting conditions influenced all dependent variables at P < 0.05. The higher roasting temperatures had a significant effect (P < 0.05) on phospholipids, phenols, and α-tocopherols contents, while longer roasting time had a significant effect (P < 0.05) on γ-tocopherol content and antioxidant capacity, among the samples prepared under different roasting conditions. The optimum conditions for roasting the hull-less pumpkin seeds were 120 °C for duration of 49 min, which resulted in these oil concentrations: phospholipids 0.29%, total phenols 23.06 mg/kg, α-tocopherol 5.74 mg/100 g, γ-tocopherol 24.41 mg/100 g, and an antioxidative activity (EC(50)) of 27.18 mg oil/mg DPPH.
authors.affiliation: College of Professional Studies in Business Management and Communications, Mitropolita Stratimirovica 110, Sremski Karlovci, Serbia.
authors.forename: Vesna
authors.initials: V
authors.lastname: Vujasinović
authors.forename: Olga
authors.initials: O
authors.lastname: Radočaj
authors.forename: Etelka
authors.initials: E
authors.lastname: Dimić
mesh_terms: D000975:Antioxidants / Q000032:analysis; D001713:Biphenyl Compounds / Q000032:analysis; D003296:Cooking / Q000379:methods*; D028464:Cucurbita / Q000737:chemistry*; D006358:Hot Temperature; D010636:Phenols / Q000032:analysis; D010743:Phospholipids / Q000032:analysis; D010851:Picrates / Q000032:analysis; D012639:Seeds / Q000737:chemistry*; D024502:alpha-Tocopherol / Q000032:analysis; D024504:gamma-Tocopherol / Q000032:analysis
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D010636:Phenols; D010743:Phospholipids; D010851:Picrates; D024504:gamma-Tocopherol; C004931:1,1-diphenyl-2-picrylhydrazyl; D024502:alpha-Tocopherol