OPTIMIZATION OF AN AQUEOUS EXTRACTION PROCESS FOR FLAXSEED GUM BY RESPONSE-SURFACE METHODOLOGY

Aqueous extraction of hydrocolloidal gum from flaxseed was optimized using response surface methodology. Extraction temperature (25-100-degrees-C), pH (2.0-7.0) and water:seed ratio (6.0-20.0) were the factors investigated with respect to yield, apparent viscosity and protein content of the final gum extracts. Temperature and pH were found to have a significant influence on both yield and quality of the extracted crude gum while the water:seed ratio had only minor effects. Optimum conditions for the extraction were a temperature of 85-90-degrees-C, a pH 6.5-7.0 and a water:seed ratio of 13. In addition, steady shear and small strain oscillatory tests on aqueous dispersions of gums, extracted under various conditions, were conducted to assess the impact of extraction conditions on the rheological properties of the flaxseed gum preparations.