Rheological and interfacial properties at the equilibrium of almond gum tree exudate (Prunus dulcis) in comparison with gum arabic

Abstract

Almond gum contains an arabinogalactan-type polysaccharide, which plays an important role in defining its interfacial and rheological properties. In this study, rheological and interfacial properties of almond gum and gum arabic aqueous dispersions were comparatively investigated. The interfacial tension of almond gum and gum arabic aqueous dispersions was measured using the pendant drop method in hexadecane. The asymptotic interfacial tension values for almond gum were significantly lower than the corresponding values measured for gum arabic, especially at high concentration. Rheological properties were characterized by steady and oscillatory tests using a coaxial geometry. Almond gum flow curves exhibited a shear thinning non-Newtonian behavior with a tendency to a Newtonian plateau at low shear rate, while gum arabic flow curves exhibited such behavior only at high shear rate. The influence of temperature (5-50 ℃) on the flow curves was studied at 4% (m/m) gum concentration and the Newtonian viscosities at infinite and at zero shear rate, for gum arabic and almond gum, respectively, were accurately fitted by an Arrhenius-type equation. The dynamic properties of the two gum dispersions were also studied. Both gum dispersions exhibited viscoelastic properties, with the viscous component being predominant in a wider range of concentrations for almond gum, while for gum arabic the elastic component being higher than the elastic one especially at higher concentrations.The rheological and interfacial tension properties of almond gum suggest that it may represent a possible substitute of gum arabic in different food applications.

Distinct Effects of two Almond Cultivars on Agreeability and Gastrointestinal Motility in Healthy Subjects: more than mere Nutraceuticals

“…Over time, almond has become increasingly important not only as a food but also for its use in cosmetics, pharmaceuticals and the food industry [42]. World almond consumption in 2014 was 1,054,231 metric tons, with 0.15 kg per capita considering the total world population [43].…”

Chemical and Functional Properties of Mahlab Tree (Prunus mahaleb) Exudate Gum

“…The emulsifying capacity increases with increasing gum concentration to achieve a maximum emulsion capacity of 100 and 52.31% for Mahlab gum and Acacia gum, respectively (Figure 2). This behavior may be linked to the absorption of gums at the oil-water interface (Sharma et al, 2020), which is responsible for the formation of stable emulsions and their ability to form structured interfacial films (Mahfoudhi et al, 2015). Different grades of Mahlab gum showed emulsion -322-capacities that were superior to those of Acacia gum.…”

“…When the apparent viscosity of Mahlab gum was compared to that of commercial Acacia gum at a concentration of 10% as shown in Figure 4 (e), the viscosity of all grades of Mahlab gum was noticeably higher than that of Acacia gum, which could be attributed to higher hydration properties of Mahlab gums. Moreover, different grades of Prunus gum solutions showed similar flow behavior characteristics of Prunus gum exudates (Qian et al, 2011) al., 2016), Prunus cerasus , Prunus dulcis (Mahfoudhi et al, 2015) and Prunus domestica (Sharma et al, 2020)…”