Effects of different isolation methods on TPS of Melicoccus bijugatus Jacq.: physicochemical and mechanical properties

The present study investigates the effects of different isolation methods on the physicochemical and mechanical properties of Melicoccus bijugatus Jacq. thermoplastic starch (TPS). Three isolation methods were used: extraction with sodium bisulfite (M1), with distilled water (M2) and by an acid process (M3). The research focused on studying the effect of the insulation method on the structural integrity and properties of the TPS. The study revealed that the isolation technique significantly influences the morphology and size of starch granules, as demonstrated in SEM analysis. FTIR spectra identified variations in hydrogen bond formation and molecular structure of starch. The TGA analyses showed differences in the thermal stability of the TPS, depending on the insulation method, with the M3 process providing the greatest thermal stability. Furthermore, DSC analysis showed variances in gelatinization temperature and gelatinization enthalpy between the different TPS materials. Regarding the mechanical properties, it was found that the insulation method affects the tensile strength and the elastic modulus of the TPS. Mechanical test results verified that the stiffness and flexibility of the TPS are directly affected by the insulation process. This research provides information on the effect that, the starch isolation methods proposed, possesses on the properties of Melicoccus TPS bijugatus Jacq. These findings are fundamental to optimize the application of TPS in various areas, considering the specific characteristics of each isolation method.