The scientists created plant protein microgels, through a process called microgeletion. In the process, plant proteins – which start off as dry with a rough texture – are placed in water and subjected to heating.
This alters the structure of the protein molecules which come together to form an interconnected network or gel which traps water around the plant proteins, they said.
The gel is then homogenised, which breaks the protein network into a microgel made up of tiny particles that cannot be seen with the naked eye. Under pressure, as they would be when they are being eaten, the microgels ooze water, creating a lubricity akin to that of single cream.
“What we have done is converted the dry plant protein into a hydrated one, using the plant protein to form a spider-like web that holds the water around the plant protein,” said Professor Anwesha Sarkar from the University of Leeds.
“This gives the much-needed hydration and juicy feel in the mouth,” Sarkar said in a statement. Plant-based protein microgels can be created without having to use any added chemicals or agents using a technique that is widely available and currently used in the food industry. The key ingredient is water. The researchers, who published their finding in the journal Nature Communications, say the dryness of plant proteins has been a “…key bottle neck for consumer acceptability”.
With the breakthrough, the team hopes consumer interest in plant-based proteins will be revitalised, encouraging people to reduce their reliance on animal products for protein intake, a necessary step if global climate change targets are to be met.
More than half of the 18 billion tonnes of carbon dioxide equivalents produced each year from food production comes from rearing and processing animal products.
The researchers say the protein microgels “…offer a unique platform to design the next generation of healthy, palatable and sustainable foods”.
The team mathematically modelled the behaviour of plant protein microgels and were confident their approach would work.
But the proof came in visualisations produced in the atomic force microscopy suite that involves a tiny probe scanning the surface of a molecule to get a picture of its shape. What those images revealed amounted to a proof of concept, the researchers said.
“The visualisations revealed that the protein microgels were pretty much spherical and not aggregating or clumping together. We could see individually spaced plant protein microgels,” Sarkar said.
“This study reveals the ingenuity and depth of science involved in modern food technology, from the chemistry of proteins, the way food is sensed in the mouth to an understanding of tribology – the friction between materials and sensory cells in the mouth,” Mel Holmes, Associate Professor at Leeds and one of the authors of the paper, said.
Given the lubricity of the microgels, akin to that of a single cream, means they could be adapted for other uses in the food processing industry, such as replacing fat that has been removed from a foodstuff to develop healthier options.
“This is quite a remarkable finding. It is striking that without adding a drop of fat, the microgels resembles the lubricity of a 20 per cent fat emulsion, which we are the first to report,” said Ben Kew, doctoral student at Leeds and lead researcher in the project.