RMIT University scientists develop technology to add ‘invisible fibre’ to foods

24-11-22 / 4 min read

series of white baguettes, traditional rustic bread style

Researchers at RMIT University in Melbourne, Australia have worked with starch processing equipment supplier Microtec Engineering Group to convert native starches such as wheat, corn and cassava into a new dietary fibre product called FiberX.

Along with his team, Associate Professor Asgar Farahnaky, Project Lead at RMIT’s Food Research and Innovation Centre, used starch modification technology in combination with approved food-grade materials (materials which are safe to come into direct contact with food), to transform plant-based starches into ‘invisible fibre’.

Like fibre, the new starch-based product resists digestion in the human gut. It can be used to fortify low-calorie, and low-GI foods and can also be made gluten free. FiberX can also be added to low-fibre foods like pasta, pizza, white bread, cakes and sauces to make them more fibrous. It is also smooth and tasteless, meaning it won’t impact the flavour or texture of foods it is mixed into.

By collaborating with Microtec, FiberX has now been developed sufficiently for the food industry to use to produce dietary fibre on a large scale, says Farahnaky. Dr Mahsa Majzoobi, Co-Researcher and Senior Research Fellow to RMIT’s Vice Chancellor, explained that the starch structure was modified on a molecular level and tested to see how it reacted when combined with digestive enzymes.

“Once the resistant starch goes through this process, it needs to have high levels of resistance to be counted as a successful conversion to dietary fibre,” she explained. The new technology allows for more than 80% of starch to be converted into dietary fibre, according to the researchers.

Fibre is an essential carbohydrate in the human diet, as it helps us maintain a healthy and functional digestive system. It can also work to prevent obesity by making people feel fuller for longer, type 2 diabetes and reduces the risk of developing some types of heart disease.

Up until now, increasing the fibre content of food products by 10 to 20% has been a major challenge for food companies. This is because adding fibre to some foods often gives it a tough texture or alters its original flavour.

After conducting a series of taste tests and texture analysis on bread and cakes using different amounts of added FiberX, the RMIT team found up to 20% of the dietary fibre could be added to foods without their texture or taste being affected.

“We can now add extra fibre to foods like white bread and other staples without changing the taste or texture, which has been one of the main issues with many commercially-available fibre supplements to date,” Professor Farahnaky commented.

“Our product is not even noticeable once added. It’s just like a parent hiding vegetables in a child’s meal to make it more nutritious.”

The next step for the RMIT team will be incorporating greener, chemical-free modification technology to convert starch into fibre.

As well as having increased health benefits, FiberX technology could also help to solve supply-chain challenges, lower food waste and provide more local jobs, Farahnaky said.

He explained: “Australia currently exports large amounts of grain for creating value-added products, such as plant-based meat. We then have to import these products back to Australia and wait for them if there are delays in the supply chain, as we saw with COVID.

“Instead of growing and exporting more grains, we should be using existing grains to create value-added products here in Australia.”

Every year, the country produces around 5,000 tonnes of pulse protein, which in turn creates 30,000 tonnes of waste. Instead of throwing this away, if this waste was processed into dry pulse starch, FiberX technology could be used to convert the starch into fibre on a large scale.

To try and achieve this goal, RMIT’s Food Research and Innovation Centre and Microtec have teamed up with government-funded Fight Food Waste Cooperative Research Centre to reduce the amount of high-fibre byproducts from plant protein production being wasted.

“Not only will this partnership help reduce food waste on a massive scale, but it will lead to creating new premium food products that are high in dietary fibre,” he commented.