Mixture design applied for the study of the tartaric acid effect on starch/polyester films

► The effect of tartaric acid in starch/PBAT blends were evaluated. ► A mixture design was used to evaluate the effects in mechanical and barrier properties. ► Intermediate proportions of tartaric acid produced films with better properties. ► Biodegradable films with good properties were obtained. ► This showed to be an interesting alternative to the non-biodegradable packaging.