title: Fenugreek (Trigonella foenum graecum) seed protein isolate: extraction optimization, amino acid composition, thermo and functional properties.
abstract: BACKGROUND
  With increasing demand for new protein sources, research on plant protein extraction and evaluation of the functional properties of protein isolates is necessary. In this study, pH and NaCl concentration, as two parameters affecting protein extraction of fenugreek seed, was investigated and the condition of fenugreek protein isolate (FPI) extraction was optimized using response surface methodology.
  
  
  RESULTS
  FPI had significantly (P< 0.05) higher protein and essential amino acid content (891.00 and 387.41 g kg(-1) , respectively) compared with soy protein isolate (SPI). FPI was rich in Asp and Glu, confirming the presence of bands in the acidic region (30-39 kDa) of its electrophoretic pattern. Differential scanning calorimeter thermography of both FPI and SPI showed two peaks with high denaturation temperature, confirming the presence of high protein content and hydrophobic amino acids. Protein solubility, foaming capacity, foam stability and emulsion stability of FPI were higher than SPI; moreover, both FPI and SPI showed pH-dependent protein functionalities.
  
  
  CONCLUSIONS
  Fenugreek seed protein extraction was optimized by control of pH and NaCl concentration. FPI could be used as a protein source with remarkable functional properties.
authors.affiliation: Department of Food Science and Technology, Ferdowsi University of Mashhad, Khorasan Razavi, PO Box 91775-1163, Iran.
authors.forename: Samira
authors.initials: S
authors.lastname: Feyzi
authors.affiliation: Department of Food Science and Technology, Ferdowsi University of Mashhad, Khorasan Razavi, PO Box 91775-1163, Iran.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Varidi
authors.affiliation: Bioresource Engineering Department, McGill University (Macdonald Campus), Ste Anne de Bellevue, QC, Canada, H9X 3 V9.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Zare
authors.affiliation: Department of Food Science and Technology, Ferdowsi University of Mashhad, Khorasan Razavi, PO Box 91775-1163, Iran.
authors.forename: Mohammad Javad
authors.initials: MJ
authors.lastname: Varidi
mesh_terms: D000596:Amino Acids / Q000032:analysis*; D000601:Amino Acids, Essential / Q000032:analysis; D002152:Calorimetry, Differential Scanning; D004032:Diet; D004044:Dietary Proteins / Q000032:analysis*; D006358:Hot Temperature; D006801:Humans; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D010936:Plant Extracts / Q000737:chemistry*; D010940:Plant Proteins / Q000032:analysis*; D011489:Protein Denaturation; D012639:Seeds / Q000737:chemistry*; D012995:Solubility; D029910:Trigonella / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D000601:Amino Acids, Essential; D004044:Dietary Proteins; D010936:Plant Extracts; D010940:Plant Proteins; C056164:fenugreek seed meal
keywords: amino acid composition; differential scanning calorimetry; electrophoretic pattern; fenugreek protein isolate; functional properties; response surface methodology