Cold‐pressing, ethanol defatting, and saline extraction enhances properties of protein products from new pennycress varieties (covercress™)

Abstract

AbstractPennycress (Thlaspi arvense L.), a winter oilseed and cover crop, is a source of novel proteins and oil for biofuel. New yellow‐seeded pennycress specialty varieties, named covercress™, were developed via conventional breeding and gene editing, but protein characteristics are still unknown. This work evaluated two covercress lines, TT8 and Y1126, for protein extraction and functionality, and the combination of cold‐pressing, alcohol‐defatting, and saline extraction to produce a protein that could align better with clean labeling. Seeds were first cold‐pressed in a tubular radial expeller then defatted at 60°C with anhydrous ethanol (‐Eth) or hexane (‐Hex) until ≤0.8% residual oil. Protein was extracted from defatted press cake (PC) using the saline method (0.1 M NaCl, 1: 10 w/v, 50°C, 2 h) for hexane‐defatted wild‐type pennycress (WTP) seed meal and PC. TT8 PC had 33%–67% more globulin and glutelin than WTP PC, but ethanol defatting reduced albumin + globulin amounts by 14%–32%. TT8 PC protein recoveries (63% and 40%) were 2‐ to 3‐fold greater than that of Y1126 PC‐Eth and their extracts had greater purity (85%–91% vs. 70% protein). Y1126 PC‐Eth protein showed a nearly constant 68%–70% solubility from pH 2 to 10, but TT8 PC‐Eth protein was more soluble in acidic pH (87%–90% solubility). Y1126 PC‐Eth protein showed greater foaming capacity (146–150 mL), while TT8 PC‐Eth protein had superior emulsifying properties (EAI 141–236 m2/g protein and ESI 13–26 min). This work demonstrated the enhanced functionality of TT8 and Y1126 proteins produced from an environmentally friendly and industrially relevant method.