Oilseed meals that are by-products from oil production are potential resources for protein. The aim of
this work is to investigate the use of enzymes in assisting in the extraction of protein from different
oilseed meals, namely rapeseed, soybean, and microalgae meals. In addition, microalgae without prior
oil removal was also tested. The extraction was performed varying temperature, pH, and type of enzyme.
More protein was extracted at alkaline conditions, compared to acidic conditions. At alkaline pH, 80%
protein of soybean meal and 15–30% protein of rapeseed and microalgae meals was extracted without
enzyme addition. The addition of enzyme under this condition increased protein extraction yield to 90%
for soybean meal and 50–80% for rapeseed and microalgae meals. Here, Protex 40XL, Protex P, and Protex
5L that work at alkaline pH assisted protein extraction particularly for rapeseed and microalgae meals.
Microalgae without prior oil removal had the lowest protein extraction yield, illustrating that oil removal
prior to protein extraction is beneficial for protein recovery. In general, protein extraction was influenced
by pH, the type of biomass, and the addition of enzyme, but not by the type of enzyme that was used.