Super spaghetti and other dietary fibre futures

Super spaghetti is just one of the items on the plate of Adelaide researchers as they develop better quality pasta with improved health benefits.

Their research goes back to the basics of cell walls and you can find out more this week at the 5th International Conference on Plant Cell Wall Biology in Palm Cove, Queensland, hosted by the ARC Centre of Excellence in Plant Cell Walls.

The conference will see renowned scientists from all over the world present their research on how cell walls are made and how this influences what plants can be used for.

Super spaghetti researchers from the ARC Centre of Excellence in Plant Cell Walls, together with colleagues in Italy, will be giving an update on their research. They have been working since 2012 to develop better varieties of durum wheat, the main source of pasta.

Wheat growing in The Plant Accelerator, Waite campus, University of Adelaide. Credit: Helen Collins

Associate Professor Rachel Burton of Plant Cell Walls at The University of Adelaide and Ilaria Marcotuli, a PhD student at The University of Bari, Italy, are the scientists behind the super spaghetti project. The focus of their research is on a component in the cell wall of the durum wheat called xylan, the source of the dietary fibre. The varieties currently used for making pasta only contain around 6% xylan, but the researchers are hopeful of increasing this.

“We have already identified some new Italian varieties with over 10% xylan but most of this extra xylan is in the bran and so would only be in wholemeal flour. However, in the endosperm, the white flour component, the structure of xylan is different and may produce better flour properties or have beneficial health properties, such as reducing the risk of heart disease or bowel cancer,” said Ilaria Marcotuli.

The ultimate aim of the project is to develop wheat that makes pasta with more and better dietary fibre.

Associate Professor Rachel Burton will also present her research with the plant Plantago, from which the commonly used dietary fibre supplement Metamucil is made. The seed husks of Plantago produce mucilage, a gelatinous substance, when in contact with water and this contains a high percentage of xylan, which makes it a great fibre supplement. Different varieties of Plantago make a different type of mucilage, containing varying amounts and types of xylan, pectin and cellulose.

Plantago ovata ruthenium red: “Pectins in Plantago mucilage stained with a pink dye. Credit: Jana Phan

 “We are able to stain this mucilage with dye, which not only gives us a quick method to see what’s in it, but also some spectacular pictures,” said Rachel Burton. “Plantago is a great plant to study to find out how xylan is made. Finding out how xylan and other dietary fibres are made is important so in future we can optimise these not only for health benefits but also for use in paper production and other industries.”

Plantago cunninghamii calcofluor: Plantago mucilage stained with a fluorescent dye that binds to cellulose. Credit: Jana Phan

These projects have received funding and support from the South Australian Government, local governments in Italy, the University of Adelaide and the ARC Centre of Excellence in Plant Cell Walls.