Thermal and Rheological Properties of a Family of Botryosphaerans Produced by Botryosphaeria rhodina MAMB-05

Abstract

Differential scanning calorimetry (DSC), thermogravimetry (TG) and Fourier-transform infra-red spectroscopy (FT-IR) analyses were performed to investigate changes in the physico-chemical properties of botryosphaerans, a family of exopolysaccharides (EPS) produced by the fungus Botryosphaeria rhodina MAMB-05 grown on glucose (EPSGLC), sucrose (EPSSUC) and fructose (EPSFRU). A slight endothermic transition and small mass loss attributable to the removal of water of hydration were observed in the DSC and TG analyses, respectively, for the three EPS samples. The FT-IR spectra confirmed no structural changes occurred during thermal treatment. Viscometry was utilized to obtain information on the rheological behaviour of the EPS in aqueous solutions. The Power Law and Cross Equations determined the natural pseudoplastic characteristics of the EPS. Comparatively, results obtained for EPS produced when B. rhodina MAMB-05 was grown on each of the three carbohydrate sources demonstrated similar apparent viscosity values for EPSGLC and EPSSUC, while EPSFRU displayed the lowest apparent viscosity of the three botryosphaerans, suggesting a higher degree of ramification and lower Mw. EPSGLC and EPSSUC possessed similar degrees of ramification. The slight differences found in their viscosities can be explained by the differences in the type of branching among the three botryosphaerans, thus varying the strength of intermolecular interactions and consequently, consistency and viscosity. The physico-chemical studies of botryosphaerans represent the originality of this work, and the knowledge of these properties is an important criterion for potential applications.

Complex Coacervation Between Gelatin and Chia Mucilage as an Alternative of Encapsulating Agents

“…Peak at 1150.3 cm −1 represent the bending vibration of C‐O‐C present in the pyranose ring (Timilsena, Adhikari et al., ). The band at 1037.2 cm −1 is assigned to C‐O‐C stretching of 1→4 glycosidic bond and C‐O‐H bending, considered as the characteristic of polysaccharide compounds (Fonseca et al., ; Toğrul & Arslan, ). The band at 886 cm −1 represents the β‐anomeric C‐H deformation and glycosidic linkages attributable to glucoryranose and xylopyranose units (Cerqueira et al., ; Timilsena, Adhikari et al., ).…”

Rheological and microstructural properties of the chia seed polysaccharide

“…For example, thermal scanning rheology, differential scanning calorimetry and polarimetry are commonly used to determine the effect of temperature on the physicochemical changes in polysaccharides such as phase transition, change of conformation, dehydration, crystallization and oxidation [5,8].…”

“…Thus, they are used as thickening, gelling, coating and syneresis control agents. They are also used as texture modifiers, emulsifiers, stabilizers and as the components of biodegradable and edible packaging films [4][5][6]. Polysaccharides are also commonly used in pharmaceutical and biomedical applications because they are biocompatible, nontoxic and can be easily modified using physical, chemical and microbiological methods.…”

Resistance-modifying Activity in Vinblastine-resistant Human Breast Cancer Cells by Oligosaccharides Obtained from Mucilage of Chia Seeds (Salvia hispanica)

“…Enzymes have become very important in industry because of their valuable properties, that is, rapid and efficient action at low concentrations under mild pH values and temperatures, high substrate specificity, and low toxicity. The Fourier transform infrared spectroscopy spectra of DMC, mucilage saponificated ( 1 ) and compounds 2 – 4 , was found to be similar to those of common gums, mucilages, and from chia mucilage (Fonseca et al, ; Wang et al, ). Thus, additional analysis using 13 C and both homonuclear and heteronuclear 2D‐NMR is vital for accurate structural elucidation.…”