Research Objective
This project aimed to evaluate the use of ozone as a practical processing option to improve the quality of pea protein ingredients by reducing undesirable off-flavours and improving colour. The goal was to determine whether ozone treatment could be integrated into existing processing systems to enhance product acceptability for food applications.
Where and how was the research conducted?
The research was conducted in Saskatchewan and is relevant to the province’s pulse processing industry, with broader applicability across Western Canada. The project was carried out through laboratory‑scale experiments considering the two main industrial processing pathways for pea protein: wet extraction (wet processing) to produce pea protein isolate (PPI), examined using wet ozonation, and air classification (dry processing) to produce pea protein concentrate (PPC), examined using dry ozonation. Ozone was applied under controlled conditions, and its effects were evaluated using analytical techniques to measure flavour compounds, colour, and functional properties of the proteins.
Why?
Plant protein ingredients, particularly pea protein, often have beany or grassy off-flavours and a yellowish colour, which limit their use in some food products and reduce their market value. Before this project, there was limited research on the use of ozone to improve pea protein quality. This project bridged a knowledge gap in identifying cost‑effective, scalable solutions to improve product quality.
How will this project benefit farmers and/or the agricultural industry?
This project supports Saskatchewan’s pulse industry by identifying processing strategies that:
- Improve the taste and appearance of pea protein ingredients
- Increase their market acceptance and value
- Enable more competitive, value‑added products
- Strengthening Saskatchewan’s position as a global leader in plant protein production
The findings indicate that ozone treatment, particularly in wet processing, has strong potential as a low‑cost, industry‑ready solution to improve product quality. In contrast, dry processing approaches may offer targeted benefits for colour improvement with further optimization.
Objective 1: Studying the effect of ozone on off-flavours and/or off-notes from plant proteins
Ozone treatment, particularly during wet processing, reduced key off-flavour compounds associated with beany and grassy notes. An approximately 20% reduction in hexanal was observed, along with a significant reduction in alcohol‑type volatiles, thereby improving overall flavour quality.
Objective 2: Assess the impact of ozone on the colour of pea protein ingredients
Dry ozone treatment improved colour by increasing lightness and reducing yellow tones, resulting in visible colour differences. Wet treatment showed minimal colour change.
Objective 3: Studying the effect of ozone on the functional properties of plant proteins
Wet ozonation caused minimal changes to protein functionality, with only slight reductions in solubility and moderate increases in water‑holding capacity. Dry ozonation caused more significant structural changes, including reduced solubility and increased water– and oil-holding capacity.
Objective 4: Conducting techno-economic analysis and recommendations
Wet ozonation was found to be more feasible, with low added cost and easy integration into existing processing systems. Dry ozonation required specialized equipment and had higher costs, limiting its commercial feasibility.
What are the results of this project in more detail?
This project demonstrated that ozone can be used as a processing option to improve pea protein quality, but performance depends strongly on how it is applied:
- Wet processing (pea protein isolate):
- Effectively reduces undesirable off-flavours
- Maintains protein functionality
- Low cost and easy to integrate into current processing lines
- Most promising option for industry adoption
- Dry processing (pea protein concentrate):
- Improve appearance by producing a lighter, less yellow product.
- However, increases the levels of oxidation‑related compounds, which can lead to undesirable flavours.
- Causes more significant changes in protein structure and functionality.
- Requires additional equipment and higher operating costs.
Further work is recommended to scale up and optimize ozone treatment systems for commercial processing environments.
What benefit do these outcomes bring to farmers in Saskatchewan?
- Supports development of higher-value pulse products.
- Improves market competitiveness of Saskatchewan-grown peas.
- Enables processors to produce better-tasting, more appealing ingredients.
- Helps expand the use of plant proteins in food products, increasing demand for pulses.
- Provides a cost-effective processing solution that the industry can adopt.