Biodegradable and UV resistant wood starch gluten nanocomposites (WSGNC) were prepared successfully from the natural polymers like starch and gluten, natural crosslinker and natural solvent via a green route using solution blending technique followed by compression molding. In this procedure, the starch gluten (50/50) blend was grafted with methyl methacrylate (MMA‐g‐SG) and citric acid was used to crosslink the MMA‐g‐SG with wood flour from Ipomoea carnea using water as a solvent. Later, Nano TiO2 was added in the composites to improve the properties like UV stability and flammability. The effects of TiO2 nanoparticles on biodegradability and UV stability of the composites were thoroughly investigated. The bacterial growth on the samples was analyzed by UV spectrophotometry and morphological features of the bacterial degraded samples was investigated by SEM study. The UV‐degraded samples were analyzed by FTIR and SEM study. It was observed that the incorporation of 3 phr TiO2 in the composites significantly improved the UV stability and hardness values of the composites. The flammability and dimensional stability of the nanocomposite were also improved with 3 phr nano TiO2 loading compared to TiO2‐untreated composites. POLYM. COMPOS., 40:46–55, 2019. © 2017 Society of Plastics Engineers