Task 3: Novel Technologies to Optimise Oat Husk Valorisation

Objective:

Optimisation of pre-treatment and extraction of oat husk
Production scale-up for optimised processes
Material balance and cost-benefit analysis of extraction technologies
Development of a zero-waste strategy for oat husk valorisation

Lead Researcher & Institutions:

Brijesh Tiwari (Teagasc), UCD, White’s Oats

Timeline:

Start Month: Month 1
End Month: Month 48

Task Description

This task will employ state-of-the-art technologies for the valorisation of oat husk. Oat husks consist mainly of cell wall components (cellulose/hemicellulose >80%), lignin (up to 10%), proteins (1–5%), and lipids (1–2.5%). A cascading valorisation strategy will be applied to recover multiple fractions using green extraction technologies.

Pulsed Electric Field (PEF): electric voltage, pulse width, pulse number, temperature Ionic liquids extraction: type and concentration of ionic liquids, liquid/solid ratio, pH Ultrasound-assisted extraction: time, power, amplitude, frequency (static and dynamic conditions)
Supercritical/subcritical extraction: pressure, temperature, flow rate
Enzyme-assisted extraction: enzyme concentration, pH, temperature, extraction time
Microwave-assisted extraction: extraction time and microwave power

Task 3.1: Characterisation of oat husks (Month 1–Month 6)

Oat by-products vary significantly depending on cultivar, season, geography, and extraction process. To reduce variability, raw material will be homogenised by mixing batches from different producers to achieve consistent composition. This will ensure stable extraction performance and reproducible outputs.

Task 3.2: Pre-treatment of oat husks for valorisation (Month 3–Month 18)

Pre-treatment technologies such as ultrasound, microwave, and PEF will be applied prior to conventional extraction to improve efficiency.

Conventional extraction variables include temperature, pH, time, solid/liquid ratio, particle size, and raw material variety.

Outputs will be evaluated based on crude protein, amino acid profile, crude oil, antioxidant capacity (e.g. DPPH scavenging activity), and other bioactives. These results will support comparison between conventional and novel extraction technologies.

Task 3.3: Development of new extraction processes (Month 6–Month 24)

Novel extraction techniques including PEF, ionic liquids, enzyme-assisted extraction, ultrasound-assisted extraction, and microwave-assisted extraction will be optimised for recovery of proteins and bioactive compounds.

Response Surface Methodology will be used to identify optimal extraction parameters and interaction effects. Both extrinsic and intrinsic variables will be optimised for each technique.

Combined approaches (enzyme + ultrasound, enzyme + microwave, enzyme + PEF) and sequential extraction strategies will also be evaluated.

Outputs will be compared against conventional extraction methods from Task 3.2.

Task 3.4: Characterisation of extracted compounds (linked to Tasks 4 & 6)

Physicochemical properties will be assessed including gel-forming ability, gel strength, water/oil binding capacity, viscosity, and elasticity. Mechanical properties will be analysed using compression testing.

Nutritional profiling will include amino acid profile (proteins), fatty acid profile (lipids), antioxidant and bioactive profiling, vitamins, minerals, and secondary metabolites.

Analytical methods will include UPLC, HPLC-DAD, and LC-MS.

Task 3.5: Scale-up of production process (Month 36–Month 40)

The most promising processes from Task 3.3 will be scaled up to at least 50 kg raw material processing. Full material balance for targeted compounds will be developed.

A computational process model will be built using engineering software and mathematical modelling to simulate extraction conditions and optimise scale-up. A Life Cycle Assessment (LCA) will also be performed. The model will be validated using experimental and literature data and will support predictive optimisation for industrial application.

Outputs will support Tasks 6 and 7.

Task 3.6: Valorisation of leftover biomass (Month 40–Month 48)

Residual biomass from scaled-up processes will be evaluated for additional applications. Integration with anaerobic digestion systems will be explored to support a zero-waste strategy.

Task 3.7: Sustainability optimisation of waste-to-product streams (Month 42–Month 48)

Sustainability modelling will be carried out based on Tasks 3.1–3.5. This will identify optimal waste-to-product pathways and define best-practice valorisation strategies for food and pharma applications.