Universidad de Buenos Aires, Facultad de Ingeniería, Buenos Aires, Argentina; CONICET - Universidad de Buenos Aires, Instituto de Tecnología en Polímeros y Nanotecnología (ITPN), Buenos Aires, Argentina.
Universidad de Buenos Aires, Facultad de Ingeniería, Buenos Aires, Argentina; CONICET - Universidad de Buenos Aires, Instituto de Tecnología en Polímeros y Nanotecnología (ITPN), Buenos Aires, Argentina; Instituto Tecnológico de Buenos Aires (ITBA), Buenos Aires, Argentina.
Int J Biol Macromol. 2024 Oct;278(Pt 3):134922. doi: 10.1016/j.ijbiomac.2024.134922. Epub 2024 Aug 22.
Aiming to contribute to the current knowledge on the impact of reaction conditions on the chemical structure and target properties of starch citrates, in the current contribution different corn starch citrates were prepared by manipulation of reaction time, temperature and citric acid concentration. Modified starches were characterized in terms of chemical structure, morphology, crystallinity, swelling power and resistant starch content. For the first time, total substitution, crosslinking and monosubstitution degrees were quantitatively determined; and the relationship among final chemical structure, reaction conditions and target starch citrates properties was comprehensively analyzed. Products with total substitution values in the range of 0.075-0.24, crosslinking degrees in the 0.005-0.11 interval, and monosubstitution extents within the 0.05-0.12 range, were produced. By proper selection of reaction conditions products with almost 100 % of resistant starch were obtained. Results evidenced that starch citrates properties (mainly swelling power and RS content) depend on both chemical structure and the reaction conditions employed. Actually, the reaction temperature set (120 °C or 150 °C) proved to play a determinant role in the final products properties as evidenced from starch citrates with similar chemical structure and substantially different swelling and digestibility properties.
为了增进人们对于反应条件对于淀粉柠檬酸酯的化学结构和目标性质的影响的认识，本研究通过改变反应时间、温度和柠檬酸浓度来制备不同的玉米淀粉柠檬酸酯。改性淀粉的化学结构、形态、结晶度、溶胀能力和抗性淀粉含量等性质都进行了表征。本研究首次定量测定了总取代度、交联度和单取代度；并综合分析了最终化学结构、反应条件与目标淀粉柠檬酸酯性质之间的关系。制备了总取代度在 0.075-0.24 之间、交联度在 0.005-0.11 之间、单取代度在 0.05-0.12 之间的产品。通过选择合适的反应条件，可以获得几乎 100%的抗性淀粉。结果表明，淀粉柠檬酸酯的性质（主要是溶胀能力和 RS 含量）取决于化学结构和反应条件。实际上，反应温度（120°C 或 150°C）对于最终产物的性质起着决定性的作用，这从化学结构相似但溶胀和消化性质差异很大的淀粉柠檬酸酯中可以看出。
