The influence of adding different polysaccharides (locust bean gum, LBG; methyl cellulose, MC; andcarboxymethyl cellulose, CMC) to gluten-based biodegradable polymeric materials was assessed in thiswork. Gluten/polysaccharide/plasticiser bioplastics were prepared at different polysaccharide concen-trations (0–4.5%) and pH values by mixing in a two-blade counter-rotating batch mixer (at 25◦C underadiabatic conditions) and thermomoulding at 9 MPa and 130◦C. Bioplastic probes were evaluated throughdynamic mechanical thermal analysis, tensile strength and water absorption capacity tests. Resultspointed out that a moderate enhancement of the network structure may be achieved by adding polysac-charide at a pH close to the protein isoelectric point (pH 6), which also conferred a further thermosettingcapacity to the system. Moreover, the addition of MC and CMC was found to significantly enhance materialelongation properties. However, the presence of charges induced by pH leaded to a higher incompatibilitybetween the polysaccharide and protein domains forming the composite. The pH value played a rele-vant role in the material water absorption, which significantly increased under acidic or basic conditions(particularly at pH 3).