Faculty of Agriculture and Food, Kunming University of Science and Technology, Kunming 650500, China.
Faculty of Chemical Engineering, Kunming University of Science and Technology, Kunming 650500, China.
Int J Biol Macromol. 2020 Dec 1;164:4104-4112. doi: 10.1016/j.ijbiomac.2020.09.010. Epub 2020 Sep 6.
Pea hull is a renewable, readily available and abundant agricultural waste whose high-value utilization deserves more attentions. This work aimed at the isolation of cellulose nanocrystals (CNC) from pea hull and evaluation its reinforcement capability for carboxymethyl cellulose (CMC) film. The obtained CNC displayed needle-like shapes with length of 81-286 nm, diameter of 8-21 nm, aspect ratio of 16 and crystallinity index of 0.77. The effects of CNC content on the morphologies, optical, mechanical, water vapor barrier and thermal properties of CMC/CNC films were investigated. SEM images showed that the CNC was evenly distributed in the CMC matrix to form homogenous films when the content of CNC was ≤5 wt%. The CMC/CNC composite films showed improved UV barrier, mechanical strength, water vapor barrier and thermal stability. Compared with pure CMC film, an increase of 50.8% in tensile strength and a decrease of 53.4% in water vapor permeability were observed for 5 wt% CNC-reinforced composite film. Furthermore, 5 wt% CNC-reinforced composite film was used for red chilies packaging, which is very effective at reducing weight loss and maintaining vitamin C compared with uncoated red chilies. These results indicated that the CMC/CNC composite film may have promising application potential as edible food packaging material.
豌豆壳是一种可再生、易得且丰富的农业废弃物，其高附加值的利用值得更多关注。本工作旨在从豌豆壳中分离出纤维素纳米晶体（CNC），并评估其对羧甲基纤维素（CMC）薄膜的增强能力。所得 CNC 呈现出长 81-286nm、直径 8-21nm、纵横比 16 和结晶度指数 0.77 的针状形状。研究了 CNC 含量对 CMC/CNC 薄膜形貌、光学、力学、水蒸气阻隔和热性能的影响。SEM 图像表明，当 CNC 含量≤5wt%时，CNC 在 CMC 基体中均匀分布，形成均匀的薄膜。CMC/CNC 复合薄膜表现出更好的 UV 阻隔、力学强度、水蒸气阻隔和热稳定性。与纯 CMC 薄膜相比，5wt% CNC 增强复合材料的拉伸强度提高了 50.8%，水蒸气透过率降低了 53.4%。此外，与未涂层的红辣椒相比，5wt% CNC 增强复合材料用于红辣椒包装，在减少失重和保持维生素 C 方面非常有效。这些结果表明，CMC/CNC 复合薄膜作为可食用食品包装材料具有广阔的应用前景。
