Novel protein-based bio-aerogels derived from canola seed meal

Novel bio-aerogels produced via the gelation of protein extracts from canola seed meal (CSM) are described for the first time, representing a new class of advanced materials that are derived from plant-based biotechnology. The bio-aerogels were synthesised by firstly manipulating the pH of the protein solution to form a gel, followed by freeze drying to form an aerogel with an average pore size and density of 75 µm and 0.13 g cm−3, respectively. The resulting protein-based structures were observed to have pores sizes down to the meso-scale. The mechanical behaviour of CSM-derived protein aerogels was investigated using static compressive testing. The average compressive elastic moduli and strength of the aerogels were 0.97 ± 0.32 MPa and 0.055 ± 0.011 MPa, respectively. The CSM-derived protein aerogels had compressive mechanical properties up to 196% of soy protein composite aerogels. The mechanical properties could also be manipulated by altering the pH and temperature during gelation. Gels held at ambient temperature during processing were revealed to have the highest elastic moduli (2.0 ± 0.6 MPa) and compressive strength (0.096 ± 0.014 MPa) at a pH of 8. In contrast, gels that were heated at 90 °C demonstrated the highest compressive modulus and strength at a pH of 10 (133% and 140%, respectively, as compared to the gel at pH 8 prepared at ambient temperature). The tunability of the mechanical properties using simple aqueous chemistry suggests this novel system of bio-aerogels has potential uses in a range of food and biopharmaceutical applications.