Influence of Hydrothermal and Chemical Modifications of Potato Starch on Its Performance as a Carrier Matrix for Selected Polyphenolic Compound Derived from Chokeberry (Aronia melanocarpa) Fruit

Abstract

Starch, a natural source of energy in the form of glucose chains, is widely utilized in various industrial and scientific fields. In its native state, starch is thermally unstable and undergoes gelatinization. Physicochemical modifications of starch aim to increase its thermal and structural stability while simultaneously enhancing its reactivity by introducing new functional groups. The primary objective of this study was to develop thermally stable and economically viable starch-based drug carriers capable of the controlled release of a negatively charged component sourced from aronia extract. Potato starch underwent a series of chemical modifications, specifically quaternary amine etherification, citric acid esterification, and/or hydrothermal modification. The characterization involved determining several parameters: the degree of amino substitution groups; starch particle size using a laser particle size analyzer; viscosity and pH; gelation temperature and heat capacity measured by scanning calorimetry (DSC); mass degradation analyzed via thermogravimetric analysis (TG); crystallinity determined by X-ray diffraction (XRD); potential intermolecular interactions studied by Fourier-Transform Infrared Spectroscopy with Attenuated Total Reflectance (FTIR-ATR); and the rate of chlorogenic acid release from aronia extract tablets quantified by spectrophotometry. The highest cationization results were achieved using citrate starches, reaching up to 86%. The combined application of citric acid esterification and cationization, coupled with an annealing process, resulted in increased viscosity, amorphousness, and enzyme resistance of the starch. Citric acid esterification significantly improved the thermal stability of the starch. Furthermore, FTIR studies revealed the formation of electrostatic interactions between the functional groups of the starch and the components of aronia extract. The amount of chlorogenic acid released showed significant variation (70–100%) depending on the type of starch modification. Collectively, these studies confirmed that both hydrothermal and chemical modifications influence the thermal and structural stability of the starch. Utilizing all combination modification strategies ensured the production of highly promising carriers for active substances.