Hydrophilic modification of cellulose nanocrystals improves the physicochemical properties of cassava starch-based nanocomposite films

• Published in: Food science & technology Vol. 86; pp. 318 - 326
• Main Authors: Ma, Xiaohan, Cheng, Yajiao, Qin, Xiaoli, Guo, Ting, Deng, Jing, Liu, Xiong
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-12-2017
• Subjects: Barrier property; Carboxymethyl cellulose nanocrystal; Cassava starch-based nanocomposite film; Mechanical property; Morphology; Cassava starch-based nanocomposite film; Barrier property; Mechanical property; Morphology; Carboxymethyl cellulose nanocrystal
• ISSN: 0023-6438; 1096-1127
• DOI: 10.1016/j.lwt.2017.08.012

Carboxymethyl cellulose nanocrystals (N-CMCs) were produced by carboxymethylation of cellulose nanocrystals (CNCs) that derived from sweet potato residue. Transmission electron microscopy showed that the N-CMCs which had a porous surface structure were more loosely packed and slightly larger with a uniform diameter ranging from 30 nm to 50 nm. N-CMCs with low viscosity (<25 mPa s) and nano-sized scale were used as reinforcement for preparing cassava starch-based films. Effect of N-CMCs varying 0.2 g/100 mL −0.5 g/100 mL was studied on physicochemical properties of N-CMCs/cassava starch films. N-CMCs/cassava starch film with 0.4 g/100 mL N-CMCs exhibited a 554% increase in tensile strength, 41% increase in elongation at break, and 123% increase in water solubility compared with the CNCs/cassava starch film. Moreover, the water vapor permeability and moisture absorption of the N-CMCs/cassava starch film decreased by 42.7% and 15.9%, respectively. Better mechanical properties, water barrier properties and water solubility was achieved for the N-CMCs/cassava starch film than for the CNC/cassava starch film, indicating N-CMCs after carboxymethylation were beneficial for reinforcement of cassava starch-based films. The moisture absorption abilities of both cassava starch nanocomposite films were comparable. The results may be applied to the development of water-soluble and biodegradable edible films for food packaging.
•The modified cellulose nanocrystals were beneficial for reinforcement of the films.•The modified cellulose nanocrystals improve the mechanical properties of the films.•The modified cellulose nanocrystals improve the barrier properties of the films.•The films reinforced with modified cellulose nanocrystals had a cohesive structure.