Protein-free cress seed (Lepidium sativum) gum: Physicochemical characterization and rheological properties

Somayeh Razmkhah; Seyed Mohammad Ali Razavi; Mohammad Amin Mohammadifar; Marcel Tutor Ale; Hassan Ahmadi Gavlighi

doi:10.1016/j.carbpol.2016.07.086

Protein-free cress seed (Lepidium sativum) gum: Physicochemical characterization and rheological properties

Carbohydr Polym. 2016 Nov 20:153:14-24. doi: 10.1016/j.carbpol.2016.07.086. Epub 2016 Jul 21.

Authors

Somayeh Razmkhah¹, Seyed Mohammad Ali Razavi², Mohammad Amin Mohammadifar³, Marcel Tutor Ale⁴, Hassan Ahmadi Gavlighi⁵

Affiliations

¹ Food Hydrocolloids Research Centre, Department of Food Science and Technology, Ferdowsi University of Mashhad (FUM), P.O. Box 91775-1163, Mashhad, Iran.
² 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.
³ Research Group for Food Production Engineering, National Food Institute, Technical University of Denmark, Søltofts Plads, 2800 Kgs., Lyngby, Denmark.
⁴ Department of Chemical and Biochemical Engineering, Technical University of Denmark, Søltoft Plads, Building 229-2800 Kgs., Lyngby, Denmark.
⁵ Department of Food Science and Technology, Tarbiat Modares University, P.O. Box 14115-336, Tehran, Iran.

PMID: 27561467
DOI: 10.1016/j.carbpol.2016.07.086

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.

Keywords: Hydrocolloid; Rheology; Shear thinning; Sugar analysis; Thermal stability; Thixotropy.

MeSH terms

Chemical Precipitation
Elasticity
Lepidium sativum / chemistry*
Plant Gums / chemistry*
Plant Proteins / isolation & purification
Rheology
Seeds / chemistry*
Shear Strength
Temperature
Uronic Acids / analysis
Viscosity

Substances

Plant Gums
Plant Proteins
Uronic Acids