Legume enriched cereal products: A generic approach derived from material science to predict their structuring by the process and their final properties

Enriching cereal products with legume flour has nutritional advantages, notably that of improving the amino acid balance, but also modifies their processability and properties. Being able to predict such modifications is a major issue for industry. In this review, we focus on the properties of the main components of cereal and legume flour (proteins and starch), and their functionality during processing of five typical cereal products (snacks, pasta, biscuits, cakes and bread), and pay particular attention to their role in structuring the product throughout processing. The nutritional and other properties (color, texture, structure, and sensory acceptability) of the legume-enriched cereal products are described. Adding legume flour changes the structure of the product and results in a different texture. As the structure is usually designed during processing, a good knowledge of the product-process interactions is required. State diagrams of starch and protein in both cereals and legumes are compared. The gelatinization and the denaturation temperatures of starch and protein in legumes are slightly higher than those of cereals. These differences may affect the structuring dynamics and the final structure of the products. Process modifications are proposed to limit such effects and are discussed in light of several results in the literature. Applying an integrative approach enabled us to demonstrate the expression of the functional properties throughout processing, from the composition of the different flours to the end products. We propose a generic representation that can be used by all those who wish to rationally formulate legume enriched cereal products.