Analytical techniques for fungal morphology and nutrient feed composition in a food application

Improving the process for making sustainable meat alternatives at scale.

Introduction

ABUNDA mycoprotein

ENOUGH produce a sustainable protein called ABUNDA which can be used as a meat alternative. ABUNDA is a mycoprotein which is produced through a fermentation process, much like sourdough or kombucha.

Challenge

The company are moving from pilot to large production scale fermentations. One of the key issues to address is consistency of the hyphal length – the long, branching filaments of a fungus which are key to the taste and texture and are also responsible for nutrient uptake while the fungus is growing. Hyphae can suffer from ‘clumping’ when agitated and this can inhibit nutrient uptake.

This project addressed how changes to hyphal length affect taste and texture (technically known as organoleptic properties) as well as how nutrient consumption can be analysed and improved during production.

Solution

ENOUGH performed fermentations and produced samples, while the University of Strathclyde team performed analyses using specialist imaging equipment at the CMAC Future Manufacturing Research Hub.

A dynamic image analysis system was used to analyse the supplied slurry samples directly from the growth media. This provided hyphal length distributions and images for all samples in order to relate the impact of process changes to sample growth.

In-situ process monitoring was conducted using a range of PAT solutions. For example Focused Beam Reflectance Measurement (FBRM), turbidity and Particle Vision and Measuremen (PVM) were assessed to see if the size could be monitored across a range of conditions while feasibility of using FTIR to measure the levels of nutrients in the culture was also investigated.

Outcome

Acceptable hyphal lengths were observed throughout continuous fermentation. A small decrease was seen over a week long culture, but this doesn’t affect organoleptic properties.

The team found that cell clumping could be monitored in-situ and that simple turbidity or image intensity probes could be used rather than more expensive alternatives. In terms of process understanding it was found that higher agitation increased cell clumping, which could affect oxygen transfer.

FTIR showed that levels of various nutrients could be detected in the broth. In the future this could be trialled in a live fermentation. The probe is expensive so it was useful to be able to demonstrate that it can work in this project.