The deformation and failure behaviour of novel ＇pseudo-ductile＇ gelatin/maltodextrin mixed biopolymer gels have been assessed using dynamic mechanical tests, conducted on the stage of a confocal laser scanning microscope. These materials exhibit a phase-separated structure, with spherical maltodextrin-rich inclusions within a continuous gelatin-rich matrix. Using both conventional tension and notched compact tension tests, it was observed that the apparent ductility was due to inclusion/matrix interfacial debonding, resulting in reduced elastic modulus. Based upon a simple debonding model, an interfacial fracture energy of similar to 0.25 J m(-2) was determined.