TY - JOUR

T1 - Influence of Reduced Molar Mass of Low-Acyl Gellan Gum on Weak Gel Formation and Rheological Properties

AU - Микушева, Нина Георгиевна

AU - Зорин, Иван Михайлович

AU - Губарев, Александр Сергеевич

AU - Иевлев, Александр Вячеславович

AU - Волина, Ольга Владимировна

AU - Цветков, Николай Викторович

PY - 2025/5/27

Y1 - 2025/5/27

N2 - Abstract: Reduced-molar-mass low-acyl gellan gum was obtained by the centrifugation of an aqueous solution of commercially available food-grade gellan gum. The derived sample was characterised by NMR, FTIR, ICPE, and viscometry methods. The charac-teristics were compared with commercially available gellan gum Gelzan™. The main focus of the investigation is on the rheological properties of low-molar-mass-gellan ion-induced gels and the influence of reduced molar mass on gelling of gellan. The gels were prepared by adding 0.2–0.3 M of NaCl or KCl to the 0.6 g/dL gellan gum aqueous solution in a 1:1 ratio. The kinetics of gelling at room temperature, studied by rheological methods, strongly depends on molar mass and is practically independent of the temper-ature (up to 37 °C) and the type of ions. Analysis of the mechanical spectra at different temperatures revealed that resulting weak gels underwent gel–sol transition with rapid subsequent recovery at a frequency depending on the molar mass. The gelling temperature achieved upon cooling for low-molar-mass gellan with a 0.1 M NaCl concentration was 39.0 °C (rheology) and 43.5–42.5 °C (visual observation). In summary, this study complements the existing knowledge about how the reduced molar mass of low-acyl gellan gum influences its rheological properties and gelling behavior in ion-induced systems and provides insights into the formulation of gellan-based gels, which can be effectively utilized in various food and pharmaceutical applications.

AB - Abstract: Reduced-molar-mass low-acyl gellan gum was obtained by the centrifugation of an aqueous solution of commercially available food-grade gellan gum. The derived sample was characterised by NMR, FTIR, ICPE, and viscometry methods. The charac-teristics were compared with commercially available gellan gum Gelzan™. The main focus of the investigation is on the rheological properties of low-molar-mass-gellan ion-induced gels and the influence of reduced molar mass on gelling of gellan. The gels were prepared by adding 0.2–0.3 M of NaCl or KCl to the 0.6 g/dL gellan gum aqueous solution in a 1:1 ratio. The kinetics of gelling at room temperature, studied by rheological methods, strongly depends on molar mass and is practically independent of the temper-ature (up to 37 °C) and the type of ions. Analysis of the mechanical spectra at different temperatures revealed that resulting weak gels underwent gel–sol transition with rapid subsequent recovery at a frequency depending on the molar mass. The gelling temperature achieved upon cooling for low-molar-mass gellan with a 0.1 M NaCl concentration was 39.0 °C (rheology) and 43.5–42.5 °C (visual observation). In summary, this study complements the existing knowledge about how the reduced molar mass of low-acyl gellan gum influences its rheological properties and gelling behavior in ion-induced systems and provides insights into the formulation of gellan-based gels, which can be effectively utilized in various food and pharmaceutical applications.

KW - coil–helix transition

KW - gellan

KW - gelling

KW - ion-induced hydrogel

KW - low-acyl gellan gum

KW - molar mass

KW - rheology

UR - https://www.mendeley.com/catalogue/b8ceb7bb-f5d4-3604-a3c3-2da12f49f954/

U2 - 10.3390/gels11060398

DO - 10.3390/gels11060398

M3 - Article

VL - 11

JO - Gels

JF - Gels

SN - 2310-2861

IS - 6

M1 - 398

ER -