Natural polysaccharide composites based on modified cellulose spheres and plasticized chitosan matrix. (May 2017)

• Record Type: Journal Article
• Authors: Ma, Xiaofei; Lv, Miaomiao; Anderson, Debbie P.; Chang, Peter R.
• Is Part Of: Food hydrocolloids. Volume 66(2017)
• Page Start: 276
• Page End: 285
• Publication Date: 2017-05
• Subjects: Chitosan -- Cellulose -- Composites -- Aldehyde group -- Chemical modification; Hydrocolloids -- Periodicals; Food additives -- Periodicals; Colloïdes -- Périodiques; Aliments -- Additifs -- Périodiques; Colloids; Food additives; Periodicals; Electronic journals; 664.06
• DOI: 10.1016/j.foodhyd.2016.11.038
• Languages: English
• ISSNs: 0268-005X

Abstract

Abstract: In order to improve the properties of chitosan films for food packaging, chitosan films were cast with a matrix reinforced with modified cellulose spheres. The high crystallinity cellulose spheres (Ces) were initially crosslinked by citric acid (to generate citric acid-crosslinked Ces (CACes)), and subsequently oxidized to produce aldehyde groups on the Ces (DACes), which formed a Schiff base (CN double bond) with the NH2 groups of the chitosan matrix. Compared to Ces, low aldehyde content DACes exhibited no obvious change in shape, crystallinity, or thermal stability, while the introduction of excess aldehyde groups (127%) resulted in disintegration of the sphere and low thermal stability. CACes and DACes fillers were incorporated into chitosan matrices leading to improved mechanical and moisture barrier properties of the composites at different relative humidities (RHs). DACes with 65% aldehyde formed the strongest interaction with the chitosan matrix among the CACes and DACes fillers, and enhanced the tensile strength from 26.8 MPa for the chitosan film to 58.2 MPa for the composite with 6% filler, while the water vapor permeability (WVP) decreased to 0.98 × 10 −6 from 1.37 × 10 −6 g m −1 h −1 Pa −1 at relative humidity of 75%. The composites also exhibited better barrier properties against UV light. Graphical abstract: Highlights: Crystalline cellulose spheres (Ces) were modified by crosslinking and oxidation. Aldehyde groups on oxidized Ces formed Schiff bases with the chitosan matrix. Composites with 65% aldehyde showed the most improved mechanical properties. Water and UV barrier properties were also enhanced.