title: Protein-free cress seed (Lepidium sativum) gum: Physicochemical characterization and rheological properties.
abstract: Protein-free cress seed gum (PFCSG) was obtained by precipitation of crude cress seed gum (CSG) with ethanol followed by treatment with protease. Molecular weight, moisture, ash and uronic acids content decreased after elimination of protein. Elimination of protein improved significantly rheological properties and thermal stability of cress seed gum. Mechanical spectra of the CSG and PFCSG were classified as weak gels and PFCSG showed stronger and more elastic network structure. The gum dispersions exhibited strong shear-thinning behavior which was described satisfactory by the Herschel-Bulkley and Moore models. Protein-free cress seed gum had higher apparent and intrinsic viscosities than the crude gum. CSG indicated lower hysteresis loop area, but degree of structural recovery of the samples showed no significant difference. The main decomposition of PFCSG started above 213°C with two peaks (at 261.72°C and 306.58°C) and initial decomposition temperature of CSG was 190.21°C with one peak at 258.28°C. DSC results coincided with those observed by thermogravimetric analysis. Enzyme treatment lowered the surface activity of CSG.
authors: Food Hydrocolloids Research Centre, Department of Food Science and Technology, Ferdowsi University of Mashhad (FUM), P.O. Box 91775-1163, Mashhad, Iran.
authors: Somayeh
authors: S
authors: Razmkhah
authors: Food Hydrocolloids Research Centre, Department of Food Science and Technology, Ferdowsi University of Mashhad (FUM), P.O. Box 91775-1163, Mashhad, Iran. Electronic address: s.razavi@um.ac.ir.
authors: Seyed Mohammad Ali
authors: SMA
authors: Razavi
authors: Research Group for Food Production Engineering, National Food Institute, Technical University of Denmark, Søltofts Plads, 2800 Kgs., Lyngby, Denmark.
authors: Mohammad Amin
authors: MA
authors: Mohammadifar
authors: Department of Chemical and Biochemical Engineering, Technical University of Denmark, Søltoft Plads, Building 229-2800 Kgs., Lyngby, Denmark.
authors: Marcel Tutor
authors: MT
authors: Ale
authors: Department of Food Science and Technology, Tarbiat Modares University, P.O. Box 14115-336, Tehran, Iran.
authors: Hassan Ahmadi
authors: HA
authors: Gavlighi
mesh_terms: D011232:Chemical Precipitation; D004548:Elasticity; D031220:Lepidium sativum / Q000737:chemistry*; D053149:Plant Gums / Q000737:chemistry*; D010940:Plant Proteins / Q000302:isolation & purification; D012212:Rheology; D012639:Seeds / Q000737:chemistry*; D033081:Shear Strength; D013696:Temperature; D014574:Uronic Acids / Q000032:analysis; D014783:Viscosity
chemical_list: D053149:Plant Gums; D010940:Plant Proteins; D014574:Uronic Acids
keywords: Hydrocolloid; Rheology; Shear thinning; Sugar analysis; Thermal stability; Thixotropy