Impact of spring rape varieties on protein extraction from press cake, emulsifying properties and antinutrient content

Artikel i vetenskaplig tidskrift, 2026

BACKGROUND: Rapeseed is the second most cultivated oilseed globally after soybean and a protein-rich press cake is generated after liberation of the oil. However, its use in food applications is limited by high levels of anti-nutrients such as glucosinolates and phytic acid. Although differences between botanical varieties are known, controlled comparisons of modern spring varieties for protein functionality and antinutrient reduction are scarce.
RESULTS: Protein was extracted from five spring rape varieties by the pH shift method, yielding 29–37% recovery. The variety Edda exhibited the best emulsifying capacity, stabilizing emulsion droplets of 44 μm (d43). Glucosinolate concentrations in the protein-rich precipitates were reduced by 89–94% compared to the press cakes, with Sigrid showing the lowest concentration (0.45 g kg⁻¹). Phytic acid content decreased by 53–81% during the extraction, with Fergus having the lowest concentration (7.6 μmol g⁻¹).
CONCLUSION: The study demonstrates that emulsifying properties and anti-nutritional content differ significantly between spring rape varieties. Selecting suitable cultivars, such as Edda for emulsification or Fergus and Sigrid for reduced anti-nutrients, can improve rapeseed protein functionality for food applications. Future studies should include multiple harvest years to strengthen these findings.