NMR and rheological study of Aloe barbadensis partially acetylated glucomannan

Abstract

The structural and rheological properties of the Aloe extract (AE) and the polysaccharidic fraction (PF) obtained from the leaves pulp of Aloe barbadensis Miller were investigated. Structural analyses carried out by composition, methylation analysis and NMR spectroscopy showed that PF is mainly constituted by a partially acetylated 4-linked β-d-glucomannan. The acetyl groups are located at C-2, C-2 and C-3, C-3 and/or C-6. The acetylation pattern of this type of polysaccharide was for the first time established using bidimensional NMR analyses. AE and PF aqueous solutions at 25°C showed a non-Newtonian behavior (with pseudoplastic characteristics), however PF showed higher apparent viscosity than AE. Dynamic oscillatory analyses showed that both samples, at the same concentration, behaved as a concentrated solution. PF presented higher values of G' compared with those of AE and this behavior could be consequence of its higher content in partially acetylated glucomannan.

Physico chemical, microstructural and sensory characteristics of low‐fat meat emulsion containing aloe gel as potential fat replacer

“…AG was taken fresh from different representative areas and was processed in these similar conditions during various repetition and replication of experiments. The physical properties (rheological) and chemical composition (carbohydrates/monosaccharide/polysaccharide/protein/acetyl) of AG from Aloe barbadensis miller have been characterised in previous studies (Campestrini et al, 2013;Lad & Murthy, 2013). The analysed pH of this AG was 4.31 AE 0.02.…”

Expression of a glucomannan mannosyltransferase gene (GMMT) from Aloe vera is induced by water deficit and abscisic acid

“…Acemannan from Aloe vera has been described in the literature as a galactoglucomannan (Minjares-Fuentes et al, 2017) and/or as a glucomannan without galactose branches (Campestrini et al 2013). In this study, using PACE analysis we show that Aloe vera acemannan lacks detectable galactose branches, since digestion with -galactosidase did not release any galactose and is only composed of glucomannan oligosaccharides similar to those described for Konjac glucomannan (Goubet et al 2002).…”

In Vivo skin hydration and anti-erythema effects of Aloe vera, Aloe ferox and Aloe marlothii gel materials after single and multiple applications

“…[1415] The starting material for Aloe vera was dehydrated gel powder (Daltonmax 700 ® ) obtained from Improve USA, Inc. (Texas, United States of America). The starting material for Aloe marlothii was obtained from natural populations near Koster in the North West Province of South Africa for which a specimen voucher (PUC 11151) was deposited at the Herbarium of the North-West University, South Africa.…”