Dissolution and Surface Tension Properties of Ethanol-Wash Solute Obtained from Industrial Sunflower Meal

Abstract

Sunflower meal ethanol-wash solute (SEWS) is one of the products obtained from a procedure for the complete valorization of industrial sunflower meal. The meal was subjected to a 4-step treatment with aqueous ethanol solution (75%) followed by vacuum concentration and lyophilization of spent ethanol wash liquids to generate powdery SEWS. The purpose of this study was to evaluate surface tension and dissolution of SEWS in water in response to two variables, concentration (0.1%, 0.3%, 0.5%) and temperature (20°C, 30°C, 40°C, 50°C). The rate constants of 0.1% and 0.3% SEWS dissolution increased in response to temperature elevations up to 40°C. For both concentrations, the dissolution at 50°C was slowed down, which resulted in deviations of the Arrhenius plot from linearity. No linear fit between rate constants and temperature increase for 0.5% SEWS was established. The addition of SEWS decreased the surface tension of pure water at all three concentrations. The most profound effect was observed at 50°C where water's surface tension (67.14 mN/m) was reduced 1.81-fold (37.35 mN/m) after adding 0.5% SEWS. Acquired characteristics are a valuable part of the SEWS's applicable profile needed for the potential use of the product in the food, nutraceutical, or agricultural industries.