Food Science Department, Federal University of Lavras, P.O. Box 3037, 37200-900 Lavras, MG, Brazil.
Food Science Department, Federal University of Lavras, P.O. Box 3037, 37200-900 Lavras, MG, Brazil.
Int J Biol Macromol. 2021 Jun 1;180:262-271. doi: 10.1016/j.ijbiomac.2021.03.076. Epub 2021 Mar 15.
The present study aimed to produce thermoplastic starch films with different concentrations of thermoplastic pectin and the addition of 4% lignin microparticles as a reinforcing and active agent. The pectin improved the modulus of elasticity, and decreased the elongation at break. In addition, it improved the UV light protection to 100% at 320 nm and 95.9% at 400 nm. The incorporation of lignin microparticles improved the thermal stability of the blends made with 25% and 50% thermoplastic pectin when compared to the pectin-free blends. The blend with 25% thermoplastic pectin led to an increase of 75.8% and 34% in elongation at break and deformation of the films, respectively. This blend also improved the UV light protection to 100% due to its dark brown color. Regarding the permeability properties, the films with 25% and 50% thermoplastic pectin showed lower oxygen permeability (48% and 65%) and an increase in the antioxidant activities from 2.7% to 71.08% and 4.1% to 79.28%, respectively. Thus, the polymer blend with 25% thermoplastic pectin with the incorporation of lignin microparticles proved to be a good alternative for use in foods sensitive to the effects of oxygen and UV light.
本研究旨在制备不同浓度热塑性果胶和添加 4%木质素微球的热塑性淀粉薄膜作为增强和活性剂。果胶提高了弹性模量，降低了断裂伸长率。此外，它将 320nm 处的紫外线防护提高到 100%，400nm 处提高到 95.9%。与不含果胶的共混物相比，木质素微球的加入提高了含有 25%和 50%热塑性果胶的共混物的热稳定性。与不含果胶的共混物相比，25%热塑性果胶的共混物使薄膜的断裂伸长率和变形分别增加了 75.8%和 34%。由于其深棕色，这种共混物还提高了紫外线防护率，达到 100%。关于透气性，含有 25%和 50%热塑性果胶的薄膜的氧气透过率较低（分别为 48%和 65%），抗氧化活性从 2.7%分别增加到 71.08%和 4.1%增加到 79.28%。因此，添加木质素微球的 25%热塑性果胶聚合物共混物被证明是对氧气和紫外线敏感的食品的良好替代品。
