@misc{9233118,
  abstract     = {{The transition to more sustainable food systems and plant-based protein sources has become increasingly important in reducing the climate impact of the food system. Rapeseed press cake is a by-product of oil extraction that has the potential to be used as a raw material for protein extraction and further use in plant-based foods, thanks to its balanced amino acid profile. Due to its bitter taste and high content of antinutritional factors, its use for human consumption is currently limited. To use rapeseed press cake as a protein source, proteins need to be extracted, purified, and separated from antinutritional compounds.

The aim of this thesis was to investigate whether the protein yield from rapeseed press cake could be improved through sequential pH precipitation, and how the protein composition was affected at different precipitation pH levels. The study also aimed to investigate how the outcome changed when scaled up to pilot scale. Furthermore, the rapeseed protein was co-extruded with pea protein isolate. During extrusion, it was investigated whether the drying step prior to extrusion could be eliminated by feeding the precipitate directly into the water inlet. 

On a laboratory scale, protein was extracted from rapeseed press cake by alkaline extraction at pH 10.5, followed by a stepwise, sequential pH precipitation at pH 7–3, with pH 7, 5.5 and 4.5 yielding the highest yield. On a pilot scale, sequential extraction was carried out in a decanter using the selected pH values. The results showed that sequential precipitation at pilot scale did not increase the yield compared to the current established method, which is precipitation at a single pH (pH 3.5). Sequential precipitation yielded a lower yield (30 %) than precipitation at pH 3.5 alone (54%). It was not possible to eliminate the drying step during extrusion. However, when freeze-dried rapeseed protein was combined with pea protein isolate, a meat analogue with a fibrous structure could be formed. SDS-PAGE analysis suggests differences in protein size for precipitation at different pH values. Cruciferin precipitated in higher concentrations at the lower pH values, whilst oleosin and napin precipitated at the higher pH values.}},
  author       = {{Bacharach, Lisa and Liedman, Amanda}},
  language     = {{swe}},
  note         = {{Student Paper}},
  title        = {{Processutveckling av rapsfrökaka: seriell pH-fällning, uppskalning och extrudering}},
  year         = {{2026}},
}