Physical properties of bacterial cellulose aqueous suspensions treated by high pressure homogenizer

In the present study, purified wet bacterial cellulose was disrupted into cellulose aqueous suspensions (0.5%, w/v) and then homogenized by 10 passes at 0, 200, 400 and 600 bar respectively. In order to evaluate the effects of high pressure homogenization (HPH) on bacterial cellulose aqueous suspensions, morphology, rheology, stability, texture, water holding capacity (WHC), water swelling ability (WSA) and water release rate (WRR) were investigated. Morphological analysis by atomic force microscopy revealed changes in microstructure and dispersion of cellulose ribbons after HPH treatment. The diameter of micro-fibril ribbons decreased from 95.6 nm to 60.3 nm with increasing pressure up to 600 bar. The rheology results suggested that all the suspensions displayed a shear thinning behaviour, moreover the suspensions treated by HPH showed 3 regions (shear thinning region, plateau region and shear thinning region again) and the flow curves followed the Herschel-Bulkley model. Furthermore, the stability and textural properties of the suspensions were enhanced after HPH treatment. Additionally, WHC and WSA of cellulose suspensions displayed high stability and the WRR increased after HPH treatment during storage. (C) 2014 Elsevier Ltd. All rights reserved.