Task 4: Impact of Processing & Formulation on the Physicochemical, Techno-Functional, Nutritional and Sensory Properties of Oat-Based Products

Objective:

Establish oat processing regimes to optimise the nutritional, physicochemical, and techno-functional properties of oats
Assess impacts of hydrolysis and formulation on techno-functional properties and in vitro bioaccessibility of protein, beta-glucan, and phenolic compounds in oat milks
Determine sensory properties of oat milks and consumer preferences

Lead Researcher & Institutions:

Andrea Silva-Espinoza (UCD), Nima Mohammadi (UCD), Teagasc, Flahavan’s

Timeline:

Start Month: Month 1
End Month: Month 48

Task Description

Oats are increasingly recognised for their health benefits, particularly due to high beta-glucan content. The growing demand for plant-based foods creates opportunities for Irish oat-based value-added products.

Challenges remain in terms of nutritional quality, texture, and off-flavours, particularly in oat-based beverages such as oat milk.
Sensory quality, bioaccessibility of nutrients, and functional stability remain underexplored, especially for formulations tailored to consumer acceptance.

Task 4.1: Establish oat processing regimes to optimise oat quality (Month 1–Month 18)

Heat treatment is essential for oat processing, as it deactivates lipase enzymes that cause rancidity and off-flavours while contributing to desirable sensory attributes. However, processing intensity can influence nutrient retention and bioactive release. This task will use lab-scale oat processing facilities (dehuller, roaster, steamer, flaker, mill, sieves) to optimise processing conditions including time, temperature, steam application, and particle size distribution. Oats will be processed with and without husks and converted into different particle sizes. Resulting products will be analysed for: macro- and micro-nutrients, particle size distribution, water absorption, water activity, emulsification properties, gelling behaviour, and flavour profiles.

Task 4.2: Impacts of formulation and enzymatic hydrolysis on oat milk functionality (Month 6–Month 30)

4.2.1 Enzymatic hydrolysis optimisation:

Oat substrates processed under optimal conditions from Task 4.1 will undergo enzymatic hydrolysis using different alpha-amylases, enzyme concentrations, and substrate-to-enzyme ratios. Rheological properties will be analysed using a stress-controlled rheometer across varying shear rates. Beta-glucan and phenolic content will also be measured.

4.2.2 Hydrocolloid and protein fortification:

Hydrocolloids (e.g., maltodextrin, gellan gum, guar gum) and protein additions will be evaluated to improve oat milk stability, viscosity, solubility, and thermal/colloidal stability. Techno-functional properties will be assessed alongside sensory profiling of selected formulations.

4.2.3 In vitro digestion and bioaccessibility:

Selected formulations will undergo in vitro digestion using the INFOGEST model. Bioaccessibility of protein, beta-glucans, and polyphenols will be assessed in digested samples to evaluate nutritional availability.

Task 4.3: Consumer sensory and preference study (Month 18–Month 48):

Consumer sensory analysis will be conducted using the UCD sensory suite. Traditional hedonic testing will be used to assess liking and preference drivers of selected oat milk formulations.

This will be complemented with biometric tools such as eye-tracking to provide deeper insights into consumer response and perception.

Milestones

Recruitment of postdoctoral researcher completed (Month 6)
Report on heating effects on physicochemical properties of oats completed (Month 18)
Optimal oat/enzyme formulation for oat milk viscosity identified (Month 24)
Report on protein and hydrocolloid impacts on oat milk properties completed (Month 30)

Deliverables

Database on oat-based product characterisation under different processing regimes (Month 18)
Processing and formulation protocols for optimised oat milk development (Month 30)
Database on in vitro bioavailability of nutrients in oat milk formulations (Month 48)
Consumer perception dataset for optimised oat milk formulations (Month 48)