(167d) Functional Properties and Physicochemical Characterization of Native Starch from Andean Crops for the Production of Sustainable Bioplastics

The use of starch in food, pharmaceutical, plastics, and construction industry is increasing due to its favorable characteristics and versatility in terms of chemical and physical modifications. The understanding of the correlation between physicochemical properties and functional properties of native starches from different botanical sources gives valuable information about the performance of starch-based bioplastics. In this study, polysaccharides from different native species of the Andean region as Zea Mays (Maize), Canna Edulis (Achira), Erythrina Edulis (Balú), Musa Paradisiaca (Plantain) were characterized through DSC, TGA, XRD, LSD, NMR, SEM techniques. From these studies, valuable data were obtained about gel features like gelatinization and thermal behavior. Besides, the evaluation of granule characteristics such as crystallinity, particle size distribution, degree of branching, and morphology, were also measured. The applicability of functional properties measurements like whiteness index, swelling power, water absorption, and solubility indexes at 40°C, was also established in this study. The determination of starch composition was carried out using methodologies based on acid-base digestion and spectrophotometry UV-Vis.

From the obtained results, differences in morphology and crystal type were found depending on the starch species from roots, leguminous, cereal grains to fruits. Even the outcomes of particle size analysis showed unimodal distribution for all the starches analyzed, but different mean particle sizes. In respect to fiber content, only small traces were found for plantain starch, which was also evident in SEM micrographs. The presence of cellulose has a definite effect on the mechanical properties of starch films. Results for functional features indicate that starch with a high-water absorption index presented higher values of swelling power. The degree of branching registered for maize starch gave the highest value, opposite to the outcome for Achira starch. Thermal behavior findings showed gelatinization temperatures between 65 to 78°C, with enthalpies from 11.8 to 15.8 J/g. These values are relevant to determine operation temperatures where gelatinized starch is required. Plantain starch exhibited higher retrogradation compared with the other studied starch species, while Balú starch presented the lowest one. This result is consistent with the determined amylose content and influences the stability of the bioproduct. Through standardized and suitable native starch characterization, the bio-based product formulation may be more accurate, as well as the large-scale operations design for optimal performance of the plant production. Likewise, different options of starch-based products would be widely diversified for value-added sustainable bioplastics made from renewable resources.