Functional Characteristics of Protein Flaxseed Concentrate Obtained Applying a Response Surface Methodology

ABSTRACT:  Food preferences by human beings are based on sensory attributes such as texture, flavor, color, and appearance that depend mainly on the interactions between minor and major components of the food. Some functional properties depend directly on the proteins, such as oil and water absorptions, foam and emulsion activities, and viscosity. The objective of this work was to obtain and evaluate the functional properties of flaxseed protein concentrate. Flaxseed was ground, defatted, and sieved to eliminate hull fiber. Surface response methodology with 5 central points and 4 axial points was used to determine how to obtain the highest protein concentrate. The independent variables used were solubilization pH (which varied from 9 to 11) and precipitation pH (which varied from 4.2 to 4.8). Treatment with a solubilization pH of 11 and a pH extraction of 4.8 gave 66.03% protein content. The flaxseed protein concentrate contained 2.56% fat, 6.62% ash, 2.44% insoluble fiber, 15.79% soluble fiber, and 6.59% sugars. The product had oil and water absorption capacities of 150.25% and 253.5%, respectively. Better foam stability (83.33%), emulsifying capacity (84.76 mL/g), and emulsifying activity (88.37%) of the flaxseed protein concentrate were observed at a pH 6. In light of its functional properties as indicated by this study, flaxseed protein concentrate may be recommended for use as an ingredient in products such as meat batters, hamburgers, and ice cream.