Organic acid-compatibilized potato starch/guar gum blend films

Abstract Global plastic pollution has increased alarmingly necessitating urgent solutions, like the development of biodegradable films. Therefore, the present study was taken up to develop and examine the effect of different organic acids on physical, barrier, mechanical, and structural properties of potato starch-guar gum based biodegradable composite film. Potato starch-guar gum films were modified by incorporating succinic, malic and tartaric acids at four different concentrations (4, 8, 12 &16%). The results of FTIR spectra showed a band at around 1724 cm−1 for all the acids incorporated films which is attributed to the formation of ester groups in the developed films. Crystallinity of all the films diminished after incorporating the organic acids into potato starch-guar gum film. It was observed that except succinic acid, other two acids contained films enhanced water vapor permeability by around 30% compared to the native potato starch-guar gum film (1.9 × 10−7 g mm/m2/Pa/s) due to higher dissociation constant the acids. Tensile strength of all the films decreased to around 2 MPa compared to native potato starch-guar gum films (8.3 MPa), whereas percentage elongation at break increased from 8.6% to 33%. Solubility in buffer solutions, opacity and morphology of the films were also investigated.