Cigi investigating how thermal treatments affect flavour of pulses in baked products

By Ellen Goodman

Cigi’s pulse area is undertaking a project investigating how infra-red heating and roasting of pulses can reduce or remove undesirable or “beany” flavours to support an increase in demand for the use of pulse ingredients as a nutritional addition to processed food products.

The year-long project, ‘Influence of pre-milling thermal treatments of field peas, dry edible beans and faba beans on the flavour and end product quality of baked products,’ is funded by Manitoba Pulse and Soybean Growers and will focus exclusively on Manitoba-grown pulses, says Peter Frohlich, Project Manager of Pulses and Specials Crops at Cigi.

Peter Frohlich with Cigi’s new Ferkar mill, suitable for testing and producing large amounts of flour from pulses and other crops.

Peter Frohlich with Cigi’s new Ferkar mill, suitable for testing and producing large amounts of flour from pulses and other crops.

“The first part of the project is focused on sourcing Manitoba-grown seed,” he says. “The second stage will be on pre-treating the pulses through roasting here at Cigi and by infra-red heating or micronization which will be done at InfraReady Products Ltd., an ingredient company we’ll be working with in Saskatoon.”

Micronization involves the exposure of the pulses to electromagnetic radiation which results in rapid heating due to the vibration of water molecules within the seeds, Peter says. Currently, micronization is used to add value to grains by causing a number of beneficial physiochemical changes. Roasting also results in physiochemical changes in seeds, although this process uses dry heat delivered through convective heat transfer.

“Both have the capacity to affect the flavour compounds in pulses,” he says. Research at Cigi has shown that extruded products such as spaghetti and expanded snacks made with thermally treated pulse flours in combination with non-pulse ingredients resulted in high-quality end products with improved functional and nutritional properties that included a reduction in any undesirable flavours.

“Successful methods that deactivate or reduce off-flavours in pulses will help to create a very attractive ingredient for food processors, an ingredient that provides a high amount of nutrition but a low level of undesirable flavours,” Peter says.

Following thermal heating, the next step in the project will involve milling the pulses into flour on Cigi’s new Ferkar mill. Purchased by Cigi through support from the Manitoba government’s Grain Innovation Hub, the mill is suitable for milling pulses and other crops, producing up to 100 kilograms of high quality flour per hour. Cigi is the first facility in Manitoba to own a Ferkar mill.

Peter says that after milling is completed, the flour will be used to bake tortillas, pan bread and pita bread, which will then undergo sensory analysis.

“Throughout the project we will be monitoring the quality and functional attributes of the pulse flours,” he says. “Knowledge on methods to effectively minimize or augment undesirable beany off-flavours in pulse flours will increase the demand for these ingredients, creating new markets and benefit the entire pulse value chain from Manitoba pulse farmers to the consumer.”