Nutrition

Incorporating pulse flour into cereal-based products can have a significant impact on the overall nutritional quality of the product. In a recent study, blending wheat-based pasta with 30% pea or lentil flour resulted in an 18-27% increase in the Nutrient Balance Score, a measure that considers both qualifying nutrients (e.g. protein, fibre, vitamins and minerals) and disqualifying nutrients (e.g. salt, fat and cholesterol).^1,7 The impact was even greater in a wheat-based breakfast cereal formulation, where incorporating 53% pea or lentil flour resulted in a 70-93% increase in the Nutrient Balance Score.

Pulse flours typically contain at least twice the amount of protein found in other flours like wheat, rice, potato, corn, and oat flours and can be used to boost the protein content of plant-based food products. For example, incorporating just 25% lentil flour into a wheat flour-based pasta adds 3 grams of protein per 100 g serving and reformulating breakfast cereal to include 53% lentil flour can add up to 78% more protein.¹

Even though most plant sources of protein have lower levels of one or more essential amino acids, blending plant protein sources that have complementary amino acid profiles can improve protein quality, potentially qualifying a product for a protein claim. Pulses have higher amounts of the essential amino acid lysine, a limiting amino acid in cereals, nuts and seeds. Blending pulse flours with flours from cereals or nuts results in a better overall quality protein.

Improving the protein quality of cereal-based foods like bakery products and pasta is important as they are a main source of protein in the diets of consumers who are increasing their intake of plant-based foods^2,3,4 Cereal-based and plant-based food options typically have a lower protein content and quality compared to animal-based protein sources. However, leveraging the high lysine content of pulse flours to make blended products provides consumers with more plant-based options that are familiar, staple foods with an improved nutritional profile for meeting protein requirements.

Flours from peas, lentils, chickpeas, and beans are clean label ingredients increasingly being used in a range of food products to make nutrition claims for elevated protein and fibre or marketing claims like gluten-free and plant-based.

Adding the right ratio of pulse flours can substantially increase the protein quality of a plant-based product. For products marketed under US or Canadian regulations, this can help to qualify a product for a protein content claim on the label. For example, reformulating wheat pasta to include 25% lentil flour increases the Protein Digestibility Corrected Amino Acid Score (PDCAAS) of the product from 0.43 to 0.71, making it qualify as a “good source of protein” in the US.

Pulse flours are very high in fibre and contain both soluble and insoluble types. Pulse flours have 2 to 5 times the amount of fibre found in other cereal-based flours. Since most of the fibre is concentrated in the outer seed coat, or hull, of the pulse, whole pulse flours generally have higher levels of fibre than dehulled pulse flours. However, the majority of hull fibre is insoluble, so a dehulled pulse flour will have a higher concentration of soluble fibre. Pulse flours can significantly boost the fibre content of food products. For example, wheat pasta enriched with 30% pea flour can have up to 150% more fibre.¹

Breakfast cereals, pasta, and bakery products are carbohydrate-rich foods. The Glycemic Index (GI) is a measure of the blood glucose-raising potential of available carbohydrates in high carbohydrate foods. The GI recognizes that equivalent amounts of available carbohydrates from different foods elicit glycemic responses which vary over a 4–5-fold range.⁸ Foods having available carbohydrate that is digested, absorbed and metabolized quickly are considered high GI foods (GI ≥ 70 on the glucose scale) whereas those with available carbohydrates that are digested, absorbed and metabolized slowly are considered low GI foods (GI ≤ 55 on the glucose scale).

Incorporating pulse flours in carbohydrate-rich foods can reduce the glycemic index. For example, incorporating 16% lentil flour into bread changed the glycemic index from medium (61) to low (53), without impacting the palatability.⁹ Consumer testing suggests that a low glycemic product claim can help your product appeal to label-scanning shoppers and stand out on the shelf.¹⁰

While GI is one measure of carbohydrate quality, several other indexes reflecting carbohydrate quality of carbohydrate-rich, packaged food products have been proposed.¹¹ The simplest one is a total carbohydrate to dietary fibre ratio of <10:1 (or ≥1 g of fibre per 10 g of carbohydrate) to identify fibre-rich carbohydrate products. Studies have shown that applying this ratio is an effective measure to identify foods with better nutritional quality with more protein, vitamins and minerals.¹¹ An example of 2 pasta products in the marketplace is provided below. The wheat product has a carbohydrate-to-fibre ratio of 20:1 whereas the red lentil product has only 5.5 grams of carbohydrates for each gram of fibre. The lentil product has almost twice the amount of protein and four times more potassium.

In addition to their high protein and fibre content, pulse flours naturally contain substantial amounts of vitamins and minerals including iron, potassium, magnesium, zinc, and folate making them a nutrient-dense flour option. Compared to most other flours, pulse flours have a higher potassium content. According to the 2020-2025 Dietary Guidelines for Americans, potassium is under-consumed and is considered a nutrient of public health concern. Food manufacturers are required to include potassium content on the new Nutrition Facts Label.

A recent study examined the nutritional quality of gluten-free products in the market and found that these products contained less protein and fibre, and higher content of saturated fat, carbohydrate and salt compared to gluten-containing products.⁵ More gluten-containing products met the nutrition claim “high in fibre” (fibre> 6 g/100 g) compared to the gluten-free products. Differences in micronutrients were observed in a selection of gluten-free breads, flakes and pasta, when compared with their respective gluten-containing counterparts.⁶

Gluten-free products were generally lower in iron and B vitamins including folate. In addition to their high fibre and protein content, pulse flours naturally contain high levels of iron and folate, making them well suited to formulating more nutritious gluten-free foods.

Pulse flours offer a unique set of nutritional benefits for food products. Because of their high protein and lysine content in particular, pulses are one of the only non-soy, plant-based ingredients that can improve the protein quality of cereal-based and plant-based foods. With a high complex carbohydrate composition, pulse flours can contribute to significant increases in the fibre content of food products, a nutrient that is lacking in the diet for most North Americans. As a nutrient-dense ingredient, they can boost nutritional content for a variety of vitamins and minerals in addition to protein and fibre. Pulse flours can also help to meet marketing claims for products that are low glycemic index, plant-based, or gluten-free.

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2. Pasiakos SM, Agarwal S, Lieberman HR, Fulgoni VL 3rd. Sources and Amounts of Animal, Dairy, and Plant Protein Intake of US Adults in 2007-2010. Nutrients. 2015;7(8):7058-7069. Published 2015 Aug 21. doi:10.3390/nu7085322
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7. Fern EB, Watzke H, Barclay DV, Roulin A, Drewnowski A. The Nutrient Balance Concept: A New Quality Metric for Composite Meals and Diets. PLoS One. 2015 Jul 15;10(7):e0130491. doi: 10.1371/journal.pone.0130491. PMID: 26176770; PMCID: PMC4503684.
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