Co-gelation of gluten and gelatin as a novel functional material formation method

Abstract

Gelatin solution was added to the gluten dispersion to obtain 25% protein from gluten and 0, 0.3, 0.6 and 1.0% of gelatin. Heat-induced gels were formed. The gelatin was leached by immersing the gel straps in distilled water at 45 °C for 2 h. Incorporation of gelatin into the gluten gel matrix resulted in its strengthening. Increase in elastic properties with the increasing amount of gelatin was also found for the macerated gels. The tangent delta showed the minimum for the leached gel with the initial concentration of gelatin 0.6%, so probably at this concentration there was some reinforcement of gluten, or the structure of gluten matrix was formed with the best ability to include gelatin inside. FTIR (Fourier transform infrared spectroscopy) results showed, that at the 0.6% gelatin concentration more gelatin was present in the leached samples than in the 1% gelatin added samples. Gelatin gels can act as an active filler reinforcing the gluten microstructure. Leaching of gelatin from the mixed gel matrix resulted in the microstructure with visible phase separation. Generally gelatin addition gave a surface smoothing effect and lower surface roughness of the obtained gels. Pure gluten gels soaking in hot water resulted in the decreased roughness. Possibility of manipulation with gluten gels surface roughness by co-gelling with gelatin can have an influence on the application of such gels as matrices for active ingredients.