Investigating aqueous phase separation of pullulan from Aureobasidium pullulans and its characterization

Singh, Ram Sarup; Kaur, Navpreet; Singh, Devinder; Kennedy, John F.

doi:10.1016/j.carbpol.2019.115103

Cited by 32 publications

(7 citation statements)

References 57 publications

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“…For electrospun pullulan fibers (Figure 8a) and pullulan powder (Figure 8b), the first transition, observed between 92 and 105 • C with peak temperature at 96.18 • C and ∆H of 2.921 J/g, is probably a result of the elimination of combined water. Conflicting results have been reported for the interpretation of this thermal event; previous studies state that, since pullulan is amorphous in nature, it shows a range of melting temperatures, with endothermic transitions instead of a clear melting point [49,50]. These authors associated this first peak with the loss of moisture from pullulan either in the form of spunfibers or as ground powder.…”

Section: Thermal Characterization Of Spunfibersmentioning

confidence: 95%

Novel Electrospun Pullulan Fibers Incorporating Hydroxypropyl-β-Cyclodextrin: Morphology and Relation with Rheological Properties

et al. 2020

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Fibers produced by electrospinning from biocompatible, biodegradable and naturally occurring polymers have potential advantages in drug delivery and biomedical applications because of their unique functionalities. Here, electrospun submicron fibers were produced from mixtures containing an exopolysaccharide (pullulan) and a small molecule with hosting abilities, hydroxypropyl-β-cyclodextrin (HP-β-CD), thus serving as multi-functional blend. The procedure used water as sole solvent and excluded synthetic polymers. Rheological characterization was performed to evaluate the impact of HP-β-CD on pullulan entanglement concentration (CE); the relationship with electrospinnability and fiber morphology was investigated. Neat pullulan solutions required three times CE (~20% w/v pullulan) for effective electrospinning and formation of bead-free nanofibers. HP-β-CD (30% w/v) facilitated electrospinning, leading to the production of continuous, beadless fibers (average diameters: 853-1019 nm) at lower polymer concentrations than those required in neat pullulan systems, without significantly shifting the polymer CE. Rheological, Differential Scanning Calorimetry (DSC) and Dynamic Light Scattering (DLS) measurements suggested that electrospinnability improvement was due to HP-β-CD assisting in pullulan entanglement, probably acting as a crosslinker. Yet, the type of association was not clearly identified. This study shows that blending pullulan with HP-β-CD offers a platform to exploit the inherent properties and advantages of both components in encapsulation applications.

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Section: Thermal Characterization Of Spunfibersmentioning

confidence: 95%

Novel Electrospun Pullulan Fibers Incorporating Hydroxypropyl-β-Cyclodextrin: Morphology and Relation with Rheological Properties

et al. 2020

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“…Usually, with the increase in the polysaccharide concentration in the thermo-gel, the sol-gel transition temperature decreases, while the gel strength and mucoadhesive force increase [11,12,21,23]. However, when neutral hydrophilic polysaccharides such as dextran, pullulan, or guar gum are mixed with pluronic, phase separation occurs [24][25][26], similar to the polymeric mixture systems of PEG (the hydrophilic component of the triblock copolymer) with dextran or pullulan [27,28].…”

Section: Introductionmentioning

confidence: 99%

Poloxamer/Carboxymethyl Pullulan Aqueous Systems—Miscibility and Thermogelation Studies Using Viscometry, Rheology and Dynamic Light Scattering

Popescu¹,

Constantin²,

Bercea³

et al. 2023

Polymers

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Thermally-induced gelling systems based on Poloxamer 407 (PL) and polysaccharides are known for their biomedical applications; however, phase separation frequently occurs in mixtures of poloxamer and neutral polysaccharides. In the present paper, the carboxymethyl pullulan (CMP) (here synthesized) was proposed for compatibilization with poloxamer (PL). The miscibility between PL and CMP in dilute aqueous solution was studied by capillary viscometry. CMP with substitution degrees higher than 0.5 proved to be compatible with PL. The thermogelation of concentrated PL solutions (17%) in the presence of CMP was monitored by the tube inversion method, texture analysis and rheology. The micellization and gelation of PL in the absence or in the presence of CMP were also studied by dynamic light scattering. The critical micelle temperature and sol–gel transition temperature decrease with the addition of CMP, but the concentration of CMP has a peculiar influence on the rheological parameters of the gels. In fact, low concentrations of CMP decrease the gel strength. With a further increase in polyelectrolyte concentration, the gel strength increases until 1% CMP, then the rheological parameters are lowered again. At 37 °C, the gels are able to recover the initial network structure after high deformations, showing a reversible healing process.

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“…3A), indicating that the hydrogen bond was improved. The C O peak also shifted (1037 → 1019 cm −1 ) as the polysaccharide was added, 38 which also suggested that the addition of PUL promoted the strength of the hydrogen bond. Gounga et al 39 also reported that hydrogen bonding in WPC/PUL film was higher than that of the control (WPI film).…”

Section: Ir Spectroscopy Of Wpc/pul Gelsmentioning

confidence: 96%

Effect of pullulan concentration and pH on the interactions between whey protein concentrate and pullulan during gelation

et al. 2020

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BACKGROUND: Whey protein concentrate (WPC)/pullulan (PUL) hydrogel is applied as a microencapsulation wall material to protect probiotics. However, the interactions between WPC and PUL during gelation have not been clarified. In the present study, the effects of PUL concentration and pH on the interactions between WPC and PUL during gelation were evaluated with respect to appearance, zeta-potential, sulfhydryl group amount, surface hydrophobicity and infrared spectroscopy measurements. The rheological properties of WPC/PUL gels were also determined. RESULTS: The results obtained showed that a proper concentration (0.40 g mL-1) of PUL could improve the gel by enhancing the strength of hydrogen bonding, electrostatic interactions and exposure of hydrophobic groups, whereas too much PUL inhibited the formation of disulfide bonds. Furthermore, hydrophobic interactions, disulfide bonds and hydrogen bonds were destroyed in varying degrees under an alkaline environment. The rheological results also demonstrated a similar effect of PUL concentration and pH on the storage modulus (G') of WPC/PUL gels. CONCLUSION: When the WPC/PUL gel was formed at PUL concentration of 0.40 g mL-1 and pH 7.0, the interaction between WPC and PUL could be enhanced, which is beneficial for the future application of WPC/PUL gels in the food industry.

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Investigating aqueous phase separation of pullulan from Aureobasidium pullulans and its characterization

Cited by 32 publications

References 57 publications

Novel Electrospun Pullulan Fibers Incorporating Hydroxypropyl-β-Cyclodextrin: Morphology and Relation with Rheological Properties

Novel Electrospun Pullulan Fibers Incorporating Hydroxypropyl-β-Cyclodextrin: Morphology and Relation with Rheological Properties

Poloxamer/Carboxymethyl Pullulan Aqueous Systems—Miscibility and Thermogelation Studies Using Viscometry, Rheology and Dynamic Light Scattering

Effect of pullulan concentration and pH on the interactions between whey protein concentrate and pullulan during gelation

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