Troncoso Victoria T, Hernandez-Hernandez Oswaldo, Alvarez María Victoria, Ponce Alejandra G, Mendieta Julieta R, Gutiérrez Tomy J
Grupo de Materiales Compuestos Termoplásticos (CoMP), Instituto de Investigaciones en Ciencia y Tecnología de Materiales (INTEMA), Facultad de Ingeniería, Universidad Nacional de Mar del Plata (UNMdP) y Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Colón 10850, B7608FLC, Mar del Plata, Argentina.
Institute of Food Science Research (CIAL) (CSIC-UAM), Nicolás Cabrera 9, 28049 Madrid, Spain.
Int J Biol Macromol. 2025 Aug;320(Pt 4):146116. doi: 10.1016/j.ijbiomac.2025.146116. Epub 2025 Jul 17.
The goal of this research work was to explore the effect of the organocatalytic esterification of the salicylyl group on hermoplastic corn (Zea mays) starch by using salicylic acid (SalAc) as active substance to be esterified, and tartaric acid (TAc) as a food-grade green organocatalyst. TAc was used to facilitate said reaction during the one-step processing (mechanochemistry) of salicylated starch-based food packaging materials obtained via reactive extrusion (REx)/thermo-molding. These efforts aimed to improve the overall performance of thermoplastic starch (TPS)-based films. To this end, four corn starch-based film systems plasticized with glycerol and containing either SalAc and TAc, individually or mixed, were processed under REx conditions. To evaluate the effect of the organocatalytic reaction on starch and its potential impact on the development of active and sustainable food packaging materials, these materials were analyzed in structural, thermal, physicochemical, surface, mechanical, and functional terms. The results obtained here demonstrated that SalAc can be esterified (grafted) onto the starch structure. However, the product of this reaction (organocatalytically salicylated starch) was not decisive in the overall physicochemical and mechanical performance of the developed materials. Instead, this study revealed that low water contents, intrinsically related to the feedstocks (starch and glycerol), determined the starch hydrolysis in the presence of SalAc or TAc. In particular, TAc showed a superior starch hydrolyzing effect than SalAc. Apart from this, protruding antimicrobial properties against Listeria innocua (Gram-positive) and Pseudomonas aeruginosa (Gram-negative) were demonstrated. Finally, films containing SalAc and TAc, at the concentrations tested, negatively affected the growth of lettuce (Lactuca sativa) seedlings (ecotoxic effect).
本研究工作的目标是通过使用水杨酸（SalAc）作为待酯化的活性物质，酒石酸（TAc）作为食品级绿色有机催化剂，探索水杨酸基团的有机催化酯化对热塑性玉米（Zea mays）淀粉的影响。TAc用于在通过反应挤出（REx）/热成型获得的水杨酸化淀粉基食品包装材料的一步加工（机械化学）过程中促进上述反应。这些努力旨在提高热塑性淀粉（TPS）基薄膜的整体性能。为此，在REx条件下加工了四种用甘油增塑且分别含有SalAc和TAc或两者混合的玉米淀粉基薄膜体系。为了评估有机催化反应对淀粉的影响及其对活性和可持续食品包装材料开发的潜在影响，从结构、热学、物理化学、表面、机械和功能等方面对这些材料进行了分析。此处获得的结果表明，SalAc可以酯化（接枝）到淀粉结构上。然而，该反应的产物（有机催化水杨酸化淀粉）对所开发材料的整体物理化学和机械性能并非起决定性作用。相反，本研究表明，与原料（淀粉和甘油）内在相关的低含水量决定了在SalAc或TAc存在下的淀粉水解。特别是，TAc显示出比SalAc更强的淀粉水解效果。除此之外，还证明了对无害李斯特菌（革兰氏阳性）和铜绿假单胞菌（革兰氏阴性）具有突出的抗菌性能。最后，在所测试浓度下含有SalAc和TAc的薄膜对生菜（Lactuca sativa）幼苗的生长产生了负面影响（生态毒性效应）。
