Elias Bou-Maroun and Nathalie Cayot
Delipidation was used to dearomatize protein powder of Eisenia foetida. The remaining volatile fraction after delipidation was studied over a period of three months. Volatile fraction dramatically increased between the first and the second month of storage. Four volatile compounds, chosen as tracers, were studied, namely: benzaldehyde, 2-pentyl furan, o-xylene, and limonene. Controlled conditions of storage are very efficient to limit volatile compound increase: 10% or less for three among the four volatile compounds chosen as tracers. The main parameter to control is temperature. To obtain a food grade protein powder, delipidation was done using ethyl acetate/ethanol instead of chloroform/methanol mixture. The remaining volatile fraction after delipidation ranged from 6% to 18%. Dearomatization was improved using an additional drying after delipidation. Solvent residues amounted to a few mg/g and conformed to EU regulations concerning solvent residues in food stuffs and food ingredients.