Economic feasibility of dry protein concentration in faba beans in France

Bean seed fractionation technology makes use of the size difference between starch grains and protein bodies and consists in finely grinding the shelled seed and then segregating it in a stream of air. According to the literature, protein-rich fraction yields can vary from 20 to 55%, with protein contents ranging from 53 to 72% and starch contents from 1.5 to 25.5%. Protein recovery in the concentrate fraction ranges from 34 to 95%. The starch-rich fraction can have protein contents ranging from 1.5 to 25% and starch contents from 46 to 83%. The protein content of the concentrate is linked to the initial protein concentration in the hulled flours. For better purification, it is possible to carry out several passes of the coarse fraction. Several suppliers on the market offer concentrations ranging from 55% to 61% protein.

Our economic feasibility study shows that a dry fractionation model for faba bean processing can be viable in a context where the price of electricity would be around €120-150/MWh.  However, the market situation with regard to the price of electricity lacks clarity, and the model has highlighted the sensitivity of the industrial margin for this type of processing to the price of energy.

It also reveals the importance of good performance in the preliminary hulling stage in terms of hull purity. Our research shows that industrial performance in this area is probably insufficient. Preliminary work on this subject is required to remove this uncertainty and/or resolve the issue.

Another issue is the sensitivity of the model to initial faba bean quality, particularly in terms of protein content. A variation of 1.5% in the initial seeds considerably changes the quality of hulled meal and concentrates, enabling a much better price to be obtained.