Improving the thermal stability of different types of xylan by acetylation

Abstract

The impact of various degrees of acetylation on improving the thermal stability of xylan isolated from different botanical source has been studied; methylglucuronoxylan from birch and eucalyptus, arabinoglucuronoxylan from spruce and glucuronoarabinoxylan from sugarcane bagasse and straw. The lower molecular weight of non-acetylated methylglucuronoxylan (17.7-23.7 kDa) and arabinoglucuronoxylan (16.8 kDa) meant that they were more soluble in water than glucuronoarabinoxylan (43.0-47.0 kDa). The temperature at the onset of degradation increased by 17-61°C and by 70-145°C for 2 low and high acetylated xylans respectively, as a result of acetylation. A glass transition temperature in the range of 121-132°C was observed for the samples non-acetylated and acetylated at low degree of acetylation (0.0-0.6). The acetylation to higher degrees (1.4-1.8) increased the glass transition temperature of the samples to 188-206°C. Acetylation proved to be an efficient method for functionalization of the xylan to increase the thermal stability.

Active role of lignin in anchoring wood-based stabilizers to the emulsion interface

“…7). Its lower molar mass value observed for sdGX (4.2 kDa) in comparison to larger values reported for glucuronoxylan elsewhere (16.5-23.7 kDa) 26,64 confirmed the occurrence of a partial hydrolysis of carbohydrates during PHWE. This was also evidenced by the broader molar mass distribution observed for sdGX (DI = 3.5) (ESI, Fig.…”

“…Chemical and structural characterization of GX samples, including carbohydrate and lignin compositions, acetyl groups content and molar mass were assessed according to previous publications. 15,26 Preparation of oil-in-water emulsion using wood-based stabilizers All GGM and GX samples were used to stabilize a suspension of water and hexadecane. Hexadecane, a hydrocarbon, was used as the oil phase herein instead of vegetable oil (mono-or polyunsaturated fatty acid) alternatives due to its minimal effect on the subsequent analytical method used for the assessment of the composition of stabilizers.…”

“…S5 †), that contrasted to the relatively monodisperse nature of purer glucuronoxylans (1.1-1.7). 26,64 During the PHWE, part of the acetyl groups from hemicelluloses were utilized as chemical source for the hydrolysis. 65 As consequence, the residual degree of acetylation (DS Ac ) of sdGX was only 0.46, a lower value compared to that attributed to native glucuronoxylan (0.7).…”

Effects of ultrasound on the degradation kinetics, physicochemical properties and prebiotic activity of Flammulina velutipes polysaccharide

“…The first stage was between 60 and 100 °C, which was connected with the evaporation of adsorbed water. The second stage was to absorb heat for oxidative decomposition [44] . The main change parameters of the second stage were shown in Table 6 .…”

Balanced Xylan Acetylation is the Key Regulator of Plant Growth and Development, and Cell Wall Structure and for Industrial Utilization

“…A recent study reported that various degrees of acetylation can improve thermal stability of xylan from different plant sources and opens new avenues for the utilization of acetylated xylan from different biomass resources for use as thermoplastics and packaging [ 134 ]. Another study reported that chemical acetylation significantly improves the thermal stability of wheat bran feruloylated arabinoxylan-based biofilms without improving the mechanical or barrier properties [ 135 ].…”