This paper describes the preparation of thermoplastic starch edible films (TPS) loaded with donut-shaped starch microparticles from two different botanical origins. The microparticles were produced by a simple thermal aqueous-alcoholic treatment. The average size was 14.01 ± 2.65 μm and 28.61 ± 6.84 μm for the microparticles from corn and pea starch, respectively. The double helical A-type and C-type crystallinity of corn and pea starch granules, respectively were converted to single helix V-type crystalline structure during the donut-shaped microparticles preparation. This crystalline distortion was revealed by X-ray diffraction, differential scanning calorimetry (DSC) and the enhanced swelling properties of the microparticles. The starch films were produced using the solution casting method with glycerol as plasticizer. The X-ray diffraction patterns showed both residual and processing induced crystallinity of the TPS films. The starch films were found to be more thermally stable by increasing the donut-shaped microparticles percentage as confirmed by the thermogravimetric analysis (TGA). The water vapour and the oxygen transmission rates through the TPS films can be modified by changing the microparticle content. The TPS films are intended mainly for food packaging applications.

本文描述了负载有来自两个不同植物来源的甜甜圈形淀粉​​微粒的热塑性淀粉可食用薄膜（TPS）的制备。通过简单的热水-醇处理产生微粒。玉米和豌豆淀粉的微粒的平均粒径分别为14.01±2.65μm和28.61±6.84μm。在甜甜圈形微粒制备过程中，玉米和豌豆淀粉颗粒的双螺旋A型和C型结晶度分别转换为单螺旋V型结晶结构。通过X射线衍射，差示扫描量热法（DSC）和增强的微粒溶胀特性可以揭示这种晶体变形。使用溶液流延法，以甘油作为增塑剂来制备淀粉膜。X射线衍射图显示了TPS膜的残留和加工诱导的结晶度。如通过热重分析（TGA）所证实的，发现通过增加甜甜圈形微粒的百分比，淀粉膜具有更高的热稳定性。通过改变微粒含量可以改变通过TPS膜的水蒸气和氧气的传输速率。TPS膜主要用于食品包装应用。