Properties of gluten foams containing different additives

Wheat gluten foams containing additives, such as zein, pine wood, and calcium carbonate, (CaCO3) were produced using a heated mold. The foams' properties were characterized using compression testing, differential scanning calorimetry, Fourier Transform Infra-red (FTIR) spectroscopy, thermogravimetric analysis, X-ray diffraction, and scanning electron microscopy (SEM). FTIR spectroscopy results indicated that foams were more aggregated than gluten powder. The addition of zein, pine wood, and CaCO3 led to significant increases in compressive modulus and strength values. The sample containing 10 wt% pine wood had the highest modulus value of 4.46 +/- 0.16 MPa and the sample containing 5 wt% CaCO3 had the highest strength value of 0.40 +/- 0.2 MPa. SEM micrographs showed compatibility of gluten with pine wood and CaCO3, which indicated effective stress transfer between gluten matrix and additives. Also, the foams had water uptake values that were more than two times that of gluten powder.