Comparing the Structural and Functional Characteristics of Novel Proteins from Pennycress (Thlaspi Arvense) and Camelina Sativa

Abstract

Justification:Global demand sustainable plant protein ingredients is peaking. Camelina and pennycress are sustainable, short season cover crops with high protein content (25-35% protein) and are thus great potential sources of protein ingredients. Developing commercially viable protein ingredients may expand the use of these sustainable crops for various food applications. Objective: The objective was to evaluate and compare the structural and functional attributes of both proteins extracted under optimized and industry feasible conditions. Methods: Defatted meals from seeds of both crops were used to extract protein following optimized salt solubilization coupled with ultrafiltration and alkaline solubilization coupled with isoelectric precipitation. Structural characterization of the protein isolates included evaluating surface hydrophobicity and charge, protein profiles, and state of denaturation. Functional properties including protein solubility, gelation, water holding capacity, and emulsification were also assessed and compared through principal component analysis. Results: Camelina and pennycress protein isolates (CPI, PcPI) from salt extraction were less denatured, and had lower surface charge and hydrophobicity than the alkaline extracted counterparts. There were significant differences in surface properties between CPI and PcPI. Salt-extracted CPI had higher surface charge and lower surface hydrophobicity than PcPI. Both PcPIs had a greater solubility than CPIs. Furthermore, salt-extracted CPI did not form a gel, while CPI from alkaline extraction had good gelation properties. PcPI also had good gelation properties, while its emulsification capacity was significantly lower compared to CPI. Significance: Results indicates that CPI and PcPI have a great potential to be utilized as novel protein ingredients that can replace partially or wholly traditional protein ingredients in various food applications. Knowledge of differences in the structural and functional attributes of these novel proteins allows for targeted selection of most suitable applications. Successful incorporation of these proteins in food systems will result in increasing the value and use of these sustainable crops.