title: Pumpkin (Cucurbita maxima) seed proteins: sequential extraction processing and fraction characterization.
abstract: Seed proteins extracted from Tunisian pumpkin seeds ( Cucurbita maxima ) were investigated for their solubility properties and sequentially extracted according to the Osborne procedure. The solubility of pumpkin proteins from seed flour was greatly influenced by pH changes and ionic strength, with higher values in the alkaline pH regions. It also depends on the seed defatting solvent. Protein solubility was decreased by using chloroform/methanol (CM) for lipid extraction instead of pentane (P). On the basis of differential solubility fractionation and depending on the defatting method, the alkali extract (AE) was the major fraction (42.1 (P), 22.3% (CM)) compared to the salt extract (8.6 (P), 7.5% (CM)). In salt, alkali, and isopropanol extracts, all essential amino acids with the exceptions of threonine and lysine met the minimum requirements for preschool children (FAO/WHO/UNU). The denaturation temperatures were 96.6 and 93.4 °C for salt and alkali extracts, respectively. Pumpkin protein extracts with unique protein profiles and higher denaturation temperatures could impart novel characteristics when used as food ingredients.
authors.affiliation: Food Conservation and Valorization Laboratory, High Institute of Food Industries , 58 Avenue Alain Savary, El Khadra City, Tunis 1003, Tunisia.
authors.forename: Leila
authors.initials: L
authors.lastname: Rezig
authors.forename: Farhat
authors.initials: F
authors.lastname: Chibani
authors.forename: Moncef
authors.initials: M
authors.lastname: Chouaibi
authors.forename: Michèle
authors.initials: M
authors.lastname: Dalgalarrondo
authors.forename: Kamel
authors.initials: K
authors.lastname: Hessini
authors.forename: Jacques
authors.initials: J
authors.lastname: Guéguen
authors.forename: Salem
authors.initials: S
authors.lastname: Hamdi
mesh_terms: D005591:Chemical Fractionation; D028464:Cucurbita / Q000737:chemistry*; D005433:Flour / Q000032:analysis; D010940:Plant Proteins / Q000737:chemistry* / Q000302:isolation & purification*; D055550:Protein Stability; D012639:Seeds / Q000737:chemistry*; D012995:Solubility
chemical_list: D010940:Plant Proteins