Effects of fibre addition on extruded products investigated

By

Cigi has been investigating how adding fibre to extruded snacks made with split yellow pea flour affects end-product quality as part of value-added research funded by Saskatchewan Pulse Growers and Manitoba Pulse Growers.

“The objective of the study is to find what the effect of fibre addition and fibre particle size has on extrusion properties of split yellow pea flour,” says Peter Frohlich, Cigi Technical Specialist. He notes that fibre has become a popular topic, with apparent benefits ranging from improving cardiovascular health to decreasing the incidence of cancer to helping with weight loss.

“We can make an extruded food product with split yellow pea flour and make it even healthier by adding more fibre,” he says.  “However, we know that more fibre can also affect quality so you can’t add any amount and expect the product to stay the same. Ideally there would be an optimum amount that can be added without compromising product quality.”

Phase one of the project , completed over the past year, involved adding three different levels of fibre consisting basically of milled pea hulls, he says. “The more fibre that is added, the less the expansion ratio, or puffiness, of the product and the more dense it becomes. We also analyzed the colour and texture of the snacks which showed a darker colour and a decrease in crispiness with more fibre.”

The aim of phase one was to determine whether the pilot scale extruder could be used effectively , he says.

Phase two of the project, still ongoing, involves increasing the number of levels of fibre added with analysis of the effect of fibre particle size on expansion of the product. “Some studies suggest a smaller particle size will have less of an effect on expansion ratio, so that is why we are looking at it.”