Pulse variety, growing location have impact on end-product quality: Cigi study

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When pulses are used as ingredients in food products, pulse variety and growing location can have an impact on end-product quality, according to a Cigi study, suggesting attributes important to the food industry should be considered in the development of new pulse varieties.

Peter Frohlich, Cigi Manager of Pulses and Special Crops, says results from the first year of a Genotype and Environment (GxE) study of pulses from the 2016 crop year revealed differences between varieties that affect product quality. He presented the findings at the annual Prairie Grain Development Committee (PGDC) meeting in February.

Peter Frohlich in Cigi’s pulse milling facility.

The study is part of an ongoing project investigating the composition and functional characteristics of pulses in baked products, with in-kind support and funding for equipment from the U.K. bakery Warburtons and additional funding from Saskatchewan Pulse Growers, Manitoba Pulse and Soybean Growers, Western Grains Research Foundation and the governments of Canada and Manitoba. The project also includes investigation of the effects of pre-and post-milling treatments, pre-ferment technology, particle size and storage time on the quality, functional, characteristics and flavour of pulse flours.

Pulses in the GxE study included yellow peas, beans, lentils and chickpeas. Peter explains that a number of pulse varieties were grown at different locations in Manitoba and Saskatchewan then milled into flour and analyzed for composition and functional properties. The flours were then each blended at 20% with wheat flour and analyzed for rheological properties, baked into bread, and evaluated for processing and quality characteristics such as colour, cell structure and loaf volume. This was followed by sensory evaluation of the pan bread products.

Peter says, for example, that flour protein tested from three different varieties of yellow peas was lower at one of the growing locations. “This information is of importance because if food processors want peas with the greatest amount of protein they will be able to pick the best growing location.”

Adding pulses, which are high in protein and fibre, to wheat-based food products enhances nutritional value which can attract consumers and create opportunities for pulse ingredients and food manufacturers.

A trained sensory panel rated bread made with three yellow pea varieties. The panelists tested the effect of genotype on appearance, aroma, pulse flavour, bitterness, sweetness, aftertaste and overall acceptability.

“One variety rated higher for strong pea smell, flavour, bitterness and aftertaste which resulted in a low acceptability score (processors want the nutrient benefits of pulses but don’t want them to overtake the flavour properties of bread) which is good to know so that a breeder might decide to cross the varieties that taste better,” says Peter.

Loaves of pan bread made with 20% navy bean flour were evaluated and compared to a whole wheat control sample (left).

Flour from four navy bean varieties grown in three locations in Manitoba showed significant effects of GxE interactions on all bread quality characteristics including particle size, protein, starch, cell diameter (bread crumb structure) and bread volume. A trained panel also evaluated the sensory properties whichwere not significantly affected by genotype or environment. These results were presented in a research poster ‘Influence of Genotype and Environment on Flour and Bread Baking Properties of Navy Beans’ at the CropConnect 2018 conference in February.

“It’s important for breeders to know what we’re seeing in the results from the first year of this study because right now they are mostly focused on agronomic and growing qualities, disease resistance and yield. But the end user may be interested in qualities like pasting properties, protein or starch for processing.”

In addition, he says, this information is useful to pulse ingredient manufacturers regarding how they source raw materials as food processors require ingredients with consistent quality for their end products.

“We’ve had a really good response from industry,” Peter says. “One ingredient manufacturer said this is exactly what they need for their work with pea flour as they want the best varieties to work with. Delegates at the PGDC meeting were also quite interested in this information.”

Year two of the project has begun on samples from the 2017 crop year which will be evaluated and then compared to results from the 2016 crop. The project runs to March 2019.

See also ‘Bringing wheat and pulses together in baked products a formula for new opportunities.’