Key Laboratory of Food Nutrition and Safety, Ministry of Education, Tianjin University of Science and Technology, Tianjin, China.
Limerick Pulp & Paper Centre and Department of Chemical Engineering, University of New Brunswick, Fredericton, New Brunswick, Canada.
J Sci Food Agric. 2018 Jun;98(8):3089-3097. doi: 10.1002/jsfa.8809. Epub 2018 Feb 5.
Collagen-based films including casings with a promising application in meat industry are still needed to improve its inferior performance. In the present study, the reinforcement of carboxylated cellulose nanofibers (CNF) for collagen film, based on inter-/intra- molecular electrostatic interaction between cationic acid-swollen collagen fiber and anionic carboxylated CNF, was investigated.
Adding CNF decreased the zeta-potential but increased particle size of collagen fiber suspension, with little effect on pH. Furthermore, CNF addition led to a higher tensile strength but a lower elongation, and the water vapor and oxygen barrier properties were improved remarkably. Because the CNF content was 50 g kg or lower, the films had a homogeneous interwoven network, and CNF homogeneously embedded into collagen fiber matrix according to the scanning electron microscopy and atomic force microscopy analysis. Additionally, CNF addition increased film thickness and opacity, as well as swelling rate.
The incorporation of CNF endows collagen fiber films good mechanical and barrier properties over a proper concentration range (≤ 50 g kg collagen fiber), which is closely associated with electrostatic reaction of collagen fiber and CNF and, subsequently, the form of the homogenous, compatible spatial network, indicating a potential applications of CNF in collagenous protein films, such as edible casings. © 2017 Society of Chemical Industry.
包括肠衣在内的基于胶原蛋白的薄膜具有广阔的应用前景，仍需要改进其性能。本研究基于带正电荷的酸溶胀胶原纤维与带负电荷的羧基化纤维素纳米纤维（CNF）之间的分子内/分子间静电相互作用，研究了 CNF 对胶原蛋白薄膜的增强作用。
添加 CNF 降低了胶原纤维悬浮液的 Zeta 电位，但增加了粒径，对 pH 值影响较小。此外，添加 CNF 会导致拉伸强度提高，但伸长率降低，水蒸气和氧气阻隔性能显著提高。由于 CNF 含量为 50g/kg 或更低，因此薄膜具有均匀交织的网络结构，根据扫描电子显微镜和原子力显微镜分析，CNF 均匀地嵌入到胶原蛋白纤维基质中。此外，添加 CNF 会增加薄膜的厚度和不透明度以及溶胀率。
在适当的浓度范围内（≤50g/kg 胶原蛋白纤维），CNF 的掺入赋予了胶原蛋白纤维薄膜良好的机械性能和阻隔性能，这与胶原蛋白纤维和 CNF 的静电反应密切相关，进而形成均匀、相容的空间网络形式，表明 CNF 在胶原蛋白类蛋白薄膜（如可食用肠衣）中有潜在的应用。© 2017 英国化学学会。
