Pulse flours shown to increase nutritional properties in extruded foods

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Puffed snack foods and spaghetti made with pulse flours at Cigi have provided further evidence of the nutritional benefits and value added opportunities created from using pulses in different food applications.

The project, which started in 2009 and was funded by Saskatchewan Pulse Growers and the Manitoba Pulse Growers Association, aimed to explore the suitablity of flours processed from chickpeas, yellow peas, and red and green lentils in extruded products. Cigi presented the results in a poster presentation at the AACC International annual meeting in Palm Springs, California, October 16-19.

Technical Specialist Peter Frohlich, one of four Cigi staff involved in the project, explains that spaghetti processed with 10, 20 and 30 percent pulse flours (with durum semolina) was compared to a control sample made with 100 percent durum semolina and 100 percent whole grain durum semolina while extruded snacks made with 100 percent pulse flour were compared to a control sample made with 100 percent corn meal. The cooked spaghetti and extruded snacks were then evaluated by a sensory panel.

“As the percentage of pulse flour increased in spaghetti so did protein and dietary fibre,” he says. “Extruded snacks made with 100 percent pulse flour also contained significantly higher levels of protein and fibre than the control sample. The results show that, overall, pulses can be used in these products to make them healthier with acceptable quality that is comparable to whole wheat and whole grain products.”

This outcome can spell good news for increasing the nutritional value of a product like pasta, even though the addition of pulse flours can darken the colour, Peter says. “If a consumer can equate pulse flours to whole wheat and whole grain products then that’s definitely a positive feature since many consumers consider that a darker colour is related to food being healthier for you.”

The spaghetti made with pulse flours was firmer than the control samples made using 100 percent durum and 100 percent whole grain durum semolinas, he says. A sensory panel found little difference in firmness between the three levels of pulse flour in cooked spaghetti with the exception of red lentils. “There also wasn’t any detectable difference in flavour intensity between the flours but there was a small difference compared to the control samples. People on our sensory panel who have eaten pasta made with regular durum semolina for years said they enjoyed a different flavour which is an attribute that can be used commercially as well.”

Peter says that when using pulse flours in the extruded snack products the expansion ratio, or puffiness, decreased compared to the corn meal control sample, mainly due to reduced starch content. Aside from the control sample, yellow pea flour showed the best expansion ratio while chickpea flour did not perform well. The sensory panel found differences in hardness between the samples although little difference was detected in flavour among the samples.

“It depends on what a food manufacturer wants, but I think trying different combinations of flours and processing parameters could be looked at to further improve the nutritional and end product quality of the snacks,” he says.“We know the flours are suitable in these products, that they improve the nutrition content especially in terms of the protein and fibre levels while maintaining acceptable quality characteristics, so it’s up to commercial food processors to take the next steps.”

“This work is part of on-going value added research that Cigi is doing on behalf of the Saskatchewan and Manitoba pulse growers” says Dr. Linda Malcolmson, Manager of Special Crops, Oilseeds and Pulses at Cigi. “Cigi’s research showcases the use of pulse flours in various food applications. The next step is to discuss with food manufacturers why adding pulse flours to their formulations is an advantage to them. We were doing just that at the conference in Palm Springs where we had a booth as part of the trade exhibit.”

For more information: pfrohlich@cigi.ca or lmalcolmson@cigi.ca

Article originally published in Cigi.ca e-publication, Fall 2011.