| Despite of being environmentally friendly, biocompatible, rich in chemical functionality and abundant as residual materials, soy proteins (SPs) are used for low added value applications. In this work, SPs were studied and used as potentially useful biomacromolecules for different industrial applications with high added value.;Initially the effect of acid hydrolysis of soy proteins as a potential route for subsequent surface modification was studied, finding that SP hydrolysates tend to form less aggregates and to adsorb at faster rates compared with unmodified SP; nevertheless, it was also found that the amount of protein adsorbed and water contact angle of the treated surface does not change significantly.;Secondly, the gel forming properties of SPs were used to produce aerogels with densities in the order of 0.1 g/cm3. To improve their mechanical properties, the reinforcement of these materials with cellulose nanofibers was studied, obtaining composite aerogels with SP loadings as high as ca. 70% that display a compression modulus of 4.4 MPa, very close to the value obtained from the pure nanofibers aerogels. The composite materials gain moisture (up to 5%) in equilibrium with 50% RH air. Futhermore, their physical integrity is unchanged upon immersion in polar and non-polar solvents, exhibiting sorption rates dependent on the aerogel composition, morphology and swelling abilities.;Finally, different soy protein based products and derivatives were used to enhance the dry strength properties of wood fibers in paper production. Experiments using soy flour, soy protein isolate, soy protein isolate hydrolysates, cationized soy flour, and soy flour combined with cationic starch and chitosan were done, obtaining satisfactory results when soy protein flour was utilized in combination with conventional treatments involving cationic polymers.;The current results confirm the opportunity to valorize residual soy products that are underutilized today as alternatives to oil derived chemicals used in chemical processes. |
