Extrusion-aided Faba bean protein fractionation

Abstract

Sustaining the availability of plant-based protein alternatives to meet the growing demand is crucial. Texturized vegetable protein (TVP) is one of the plant-based alternatives available; however, the production of TVP involves energy and water-intensive processes for protein enrichment of the raw material. The state-of-the-art dry-extrusion-aided plant protein fractionation process, recently patented by VTT, presents a promising alternative for the existing protein-enrichment methods. However, despite of its potential, there is limited knowledge regarding the impact of extrusion conditions on the properties of the produced fractions. Thus, this thesis aims at identifying extrusion conditions favouring starch-protein separation, focusing on the utilization of the untapped potential of Faba bean (Vicia faba), a locally cultivated legume known for its high protein content.

Through process optimization, different conditions favouring high protein content and high protein yields in the protein-rich fraction were identified. The optimized conditions for protein content yielded a protein content of 76.78% with a protein yield of 59.84%. Additionally, when the focus shifted towards maximizing protein yield, a protein yield of 84.85% with a corresponding protein content of 71.02% was obtained. Notably, these results were relatively higher than protein concentrate and TVP available in the market.

Moreover, the optimized conditions not only resulted in high protein content and yield of protein-rich extrudates, but also demonstrated comparable techno-functional properties to commercial TVP. Additionally, the extent of protein texturization during the extrusion process determined the techno-functional attributes of the protein-rich fraction.

The dry extrusion-aided fractionation process is expected to be a more sustainable approach compared to conventional TVP production by bypassing resource-intensive flour fractionation. This research contributes valuable insights into facilitating the development of innovative and more sustainable plant-based protein alternatives.