Faba bean (Vicia faba) represents a strategic legume in the transition towards sustainable plant-based protein systems, yet conventional extraction processes generate substantial side streams with unexploited nutritional value. Recent research has focused on characterising and recovering bioactive compounds from aqueous fractions typically discarded during protein isolate production, addressing both food loss and waste reduction and resource efficiency imperatives within circular bioeconomy frameworks.
Badjona et al. (2025) conducted a systematic investigation of protein losses occurring during industrial-scale faba bean protein isolate manufacture, specifically examining the alkaline extraction filtrate conventionally regarded as waste. The methodology employed cascade filtration using 300 kDa and 10 kDa molecular weight cut-off membranes to fractionate proteins remaining in solution after conventional isoelectric precipitation at pH 4.5. The study quantified substantial protein retention in the filtrate, representing approximately 15-20% of initial flour protein content that escapes conventional recovery processes.
The researchers demonstrated that membrane ultrafiltration recovered protein concentrates exhibiting functional properties comparable to commercial isolates, including emulsification capacity and foam stability relevant to food formulation applications. Amino acid profiling revealed that recovered proteins retained nutritionally significant levels of lysine and other essential amino acids, challenging assumptions that filtrate proteins possess inferior nutritional quality (Badjona et al., 2025). These findings establish technical feasibility for integrating membrane separation into existing protein fractionation workflows.
Bioactive properties of blanching water
Feng et al. (2025) characterised the proximate composition and bioactive potential of faba bean blanching water, an aqueous fraction generated during preliminary thermal processing but systematically overlooked in valorisation studies. The experimental design subjected dehulled faba beans to standardised blanching protocols (95°C, 10 minutes), followed by comprehensive analysis of soluble protein content, peptide profiles via liquid chromatography-mass spectrometry, and functional bioactivity screening using established antioxidant and enzyme inhibition assays.
Results demonstrated that blanching water contained 8.2 g/L soluble protein, substantially higher than previously reported for legume processing waters, alongside quantifiable concentrations of low molecular weight peptides (<3 kDa) exhibiting antioxidant activity through DPPH radical scavenging and ferric reducing antioxidant power mechanisms. Peptide sequencing identified bioactive fragments homologous to known ACE-inhibitory peptides, suggesting potential cardiovascular health applications (Feng et al., 2025). The study further documented notable α-glucosidase inhibitory activity, indicating relevance for glycaemic management strategies.
Discussion and industrial implications
Collectively, these investigations reveal that aqueous side streams from faba bean processing harbour nutritionally and functionally valuable components amenable to recovery through accessible separation technologies. The alkaline extraction filtrate studied by Badjona et al. (2025) and the blanching water characterised by Feng et al. (2025) represent distinct processing stages, yet both demonstrate protein concentrations and bioactive profiles justifying valorisation investment. The peptide-rich nature of blanching water offers particular interest for nutraceutical applications, while filtrate proteins address bulk protein ingredient demands.
Implementation barriers centre on economic viability at industrial scale, requiring integration of membrane separation or spray-drying infrastructure within existing facilities. However, regulatory drivers including EU waste reduction mandates and growing consumer emphasis on sustainability credentials increasingly favour adoption of side stream valorisation. Protein functionality testing by Badjona et al. (2025) provides formulation guidance for recovered ingredients, while the bioactivity data from Feng et al. (2025) support product health claims under emerging functional food regulations.
Conclusions
These complementary studies establish that faba bean processing generates multiple aqueous fractions containing recoverable proteins and bioactive peptides currently lost to waste streams. Badjona et al. (2025) demonstrated technically feasible protein isolation from alkaline filtrates using membrane technology, recovering 15-20% of initial flour protein with preserved functional properties. Feng et al. (2025) characterised blanching water as a source of bioactive peptides exhibiting antioxidant and enzyme inhibitory activities relevant to health applications. Both investigations support the business case for circular economy approaches in legume processing, transforming disposal costs into revenue-generating value streams while advancing sustainability objectives. Future research should prioritise pilot-scale validation and techno-economic assessment to facilitate industrial adoption of these protein recovery strategies.
Dario Dongo
References
- Badjona, A., Bradshaw, R., Millman, C., Howarth, M., & Dubey, B. (2025). Revisiting the conventional extraction of protein isolates from faba beans: Recovering lost protein from sustainable side streams. Foods, 14(11), Article 1906. https://doi.org/10.3390/foods14111906
- Feng, Z., Morton, J. D., Maes, E., Kumar, L., & Serventi, L. (2025). Proximate composition, peptide characterization and bioactive properties of faba bean blanching water. Food Research International, 200, Article 115426. https://doi.org/10.1016/j.foodres.2024.115426
Dario Dongo, lawyer and journalist, PhD in international food law, founder of WIISE (FARE - GIFT - Food Times) and Égalité.
