da Costa Fabíola Medeiros, Melo Pamela Thais Sousa, Nishimoto Pedro Henrique Kenzo, Lorevice Marcos Vinicius, Aouada Fauze Ahmad, de Moura Márcia Regina
Hybrid Composites and Nanocomposites Group (GCNH), Department of Physics and Chemistry, School of Engineering, São Paulo State University (UNESP), Ilha Solteira 15385-000, SP, Brazil.
Brazilian Nanotechnology National Laboratory (LNNano), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas 13083-970, SP, Brazil.
Foods. 2025 Mar 24;14(7):1123. doi: 10.3390/foods14071123.
Bacterial cellulose nanocrystals (BCNCs) extracted from cellulose residues, resulting from film-cutting operations used for the commercial production of dressings, were studied as reinforcement for films based on gelatin, pectin, and hydroxypropylmethyl cellulose (HPMC). The biopolymer matrices differ in their monomer and functional group (gelatin: -COOH and -NH; pectin: -COOH and HPMC -OH). The addition of BCNCs into a polymer matrix for biopolymeric nanocomposite formulation was based on values around the theoretical percolation threshold. The results of this study showed that the BCNCs had a diameter and mean length range of (27 ± 1) nm and (180 ± 10) nm, respectively, producing films reaching 120.13 MPa of tensile strength, 10.9 GPa of Young's modulus, and a toughness of 335.17 × 10 J/m. All films showed good transparency and a smooth surface. Surface micrographs (SEM) revealed homogeneous, compact, smooth regions, and no macropores. The crystallinity index of the BCNCs produced was 68.69%. The crystallinity of the gelatin, pectin, and HPMC films improved from 10.25 to 44.61%, from 29.79 to 53.04%, and from 18.81 to 39.88%, respectively. These results show the possibility of using films for freeze-dried food packaging.
从用于商业生产敷料的薄膜切割操作产生的纤维素残渣中提取的细菌纤维素纳米晶体（BCNCs），被研究用作基于明胶、果胶和羟丙基甲基纤维素（HPMC）的薄膜增强剂。生物聚合物基质在其单体和官能团方面存在差异（明胶：-COOH和-NH；果胶：-COOH；HPMC：-OH）。将BCNCs添加到聚合物基质中用于生物聚合物纳米复合材料配方是基于接近理论渗滤阈值的值。本研究结果表明，BCNCs的直径和平均长度范围分别为(27±1)nm和(180±10)nm，所制备的薄膜的拉伸强度达到120.13MPa，杨氏模量为10.9GPa，韧性为335.17×10J/m。所有薄膜均表现出良好的透明度和光滑的表面。表面显微照片（SEM）显示区域均匀、致密、光滑，且无大孔。所制备的BCNCs的结晶度指数为68.69%。明胶、果胶和HPMC薄膜的结晶度分别从10.25%提高到44.61%、从29.79%提高到53.04%、从18.81%提高到39.88%。这些结果表明了将这些薄膜用于冻干食品包装的可能性。
