Department of Food Science and Human Nutrition, Iowa State University, Ames, IA 50011, USA; Department of Food Engineering, Ponta Grossa State University, Ponta Grossa, PR 84030900, Brazil.
Department of Food Science and Human Nutrition, Iowa State University, Ames, IA 50011, USA.
Int J Biol Macromol. 2019 Oct 15;139:1151-1161. doi: 10.1016/j.ijbiomac.2019.08.115. Epub 2019 Aug 13.
Cassava bagasse, a high-fiber coproduct of cassava starch processing, was used to produce lignocellulose nanofibers (LCNF) to apply as reinforcement in cassava starch films. LCNF-reinforced cast starch films were evaluated for changes in structural, thermal and mechanical properties and compared with control films reinforced with commercial grade nanoclay (Nclay). Five different types of cassava starch cast-films were produced: no-reinforcement control, two LCNF-reinforced, and two Nclay-reinforced, each at 0.65 and 1.3% w w. The LCNF morphology showed the characteristic microscopic structure of lignocellulose nanofibers, with an aspect ratio > 85 and average diameter of 4.5 nm. All reinforced films were transparent and had a good distribution of the nanoparticles within. The opacity values reduced for the films with all nanoreinforcements, compared to control. The permeability to water vapor reduced with reinforcements, with lower values for the films tested with LCNF 0.65 and Nclay 1.3. Thermal stability improved with 1.3% of LCNF and both concentrations of Nclay. Tensile stress for films increased and elongation at break value decreased with both types of nanoreinforcements.
木薯渣是木薯淀粉加工的一种高纤维副产物，被用于生产木质纤维素纳米纤维（LCNF），并将其作为增强剂应用于木薯淀粉薄膜中。对 LCNF 增强的铸塑淀粉薄膜的结构、热和机械性能变化进行了评估，并与用商业级纳米粘土（Nclay）增强的对照薄膜进行了比较。制备了五种不同类型的木薯淀粉铸塑薄膜：无增强对照薄膜、两种 LCNF 增强薄膜和两种 Nclay 增强薄膜，每种薄膜的含量均为 0.65% 和 1.3%（w/w）。LCNF 的形态呈现出木质纤维素纳米纤维的特征微观结构，长径比>85，平均直径为 4.5nm。所有增强薄膜均为透明状，纳米颗粒在其中分布良好。与对照薄膜相比，所有纳米增强薄膜的不透明度值都降低了。水蒸气透过率随着增强材料的添加而降低，其中 LCNF 0.65 和 Nclay 1.3 测试的薄膜的水蒸气透过率值更低。添加 1.3%的 LCNF 和两种浓度的 Nclay 可提高薄膜的热稳定性。随着两种类型的纳米增强材料的添加，薄膜的拉伸应力增加，断裂伸长率降低。
