Extraction, composition, and functional properties of dried alfalfa (Medicago sativa L.) leaf protein

J Sci Food Agric. 2017 Feb;97(3):882-888. doi: 10.1002/jsfa.7810. Epub 2016 Jun 17.

Abstract

Background: Alfalfa is considered a potential feedstock for biofuels; co-products with value-added uses would enhance process viability. This work evaluated dried alfalfa leaves for protein production and describes the functional properties of the protein.

Results: Dried alfalfa leaves contained 260 g kg-1 dry basis (DB) crude protein, with albumins being the major fraction (260 g kg-1 of total protein). Alkali solubilization for 2 h at 50 °C, acid precipitation, dialysis, and freeze-drying produced a protein concentrate (600 g kg-1 DB crude protein). Alfalfa leaf protein concentrate showed moderate solubility (maximum 500 g kg-1 soluble protein from pH 5.5 to 10), excellent emulsifying properties (activity 158-219 m2 g-1 protein, stability 17-49 min) and minimal loss of solubility during heating at pH ≥ 7.0.

Conclusions: It is technically feasible to extract protein with desirable emulsifying and heat stability properties from dried alfalfa leaves; however, the dried form may not be a practical starting material for protein production, given the difficulty of achieving high yields and high-purity protein product. © 2016 Society of Chemical Industry.

Keywords: alfalfa; alfalfa leaf proteins; protein extraction; protein functionality.

Publication types

  • Comparative Study
  • Evaluation Study

MeSH terms

  • Chemical Precipitation
  • Crop Production*
  • Crops, Agricultural / chemistry*
  • Dialysis
  • Emulsifying Agents / chemistry
  • Emulsifying Agents / isolation & purification*
  • Feasibility Studies
  • Food Additives / chemistry
  • Food Additives / isolation & purification*
  • Freeze Drying
  • Hot Temperature / adverse effects
  • Hydrogen-Ion Concentration
  • Medicago sativa / chemistry*
  • Midwestern United States
  • Particle Size
  • Plant Extracts / chemistry
  • Plant Extracts / isolation & purification
  • Plant Leaves / chemistry*
  • Plant Proteins, Dietary / chemistry
  • Plant Proteins, Dietary / isolation & purification*
  • Plant Stems / chemistry
  • Protein Stability
  • Solubility
  • Water / analysis

Substances

  • Emulsifying Agents
  • Food Additives
  • Plant Extracts
  • Plant Proteins, Dietary
  • Water