Influence of water deficit on the main polysaccharides and the rheological properties of Aloe vera (Aloe barbadensis Miller) mucilage

• Published in: Industrial crops and products 2017-12, Vol.109, p.644-653
• Main Authors: Minjares-Fuentes, Rafael, Medina-Torres, Luis, González-Laredo, Rubén Francisco, Rodríguez-González, Víctor Manuel, Eim, Valeria, Femenia, Antoni
• Format: Article
• Language: English
• Subjects: Acemannan; Aloe vera; Pectin; Rheological behaviour; Water deficit
• ISSN: 0926-6690; 1872-633X
• DOI: 10.1016/j.indcrop.2017.09.016

[Display omitted] •Polysaccharides and rheology of Aloe vera with water deficit were studied.•Water deficit reduced mannose from acemannan and increased the molecular weight.•Water deficit did not promote changes in the acetylation pattern of acemannan.•Viscous properties of mucilage were increased by water deficit.•Water deficit improved the viscoelastic properties of Aloe vera mucilages. The aim of this study was to evaluate the effect of water deficit on the composition of the main polysaccharides and rheological behaviour from Aloe vera (Aloe barbadensis Miller) mucilage. In particular, plants with 0 (D0), 40 (D40) and 60% (D60) water deficits were used. Water-soluble polysaccharides were isolated and subjected to carbohydrate and glycosidic linkage analysis. The steady-shear and linear oscillatory flows were studied, not only in fresh but also in reconstituted mucilages. Acemannan and pectic substances were the predominant polysaccharides in the Aloe vera mucilage, being the bioactive polymer acemannan the most affected by water deficit. Thus, increasing the water deficit by up to 60% promoted a mannose decrease of 41%, although a significant increase in its average molecular weight, from 54 to 98kDa, was detected. Interestingly, acemannan did not undergo deacetylation as a consequence of the water deficits applied. All Aloe vera mucilages, either fresh or reconstituted, exhibited a shear-thinning flow behaviour (n