ICDSUPL4-F014

Volume: 4, 2025
4th International PhD Student’s Conference at the University of Life Sciences in Lublin, Poland:
ENVIRONMENT – PLANT – ANIMAL – PRODUCT

Abstract number: F014

DOI: https://doi.org/10.24326/ICDSUPL4.F014

Published online: 9 April 2025

ICDSUPL, 4, F014 (2025)

The structure of starch gels – a microscopic evaluation

Robert Waraczewski¹*, Bartosz G. Sołowiej¹, Konrad Terpiłowski²

¹ Department of Animal Food Technology, University of Life Sciences in Lublin, Skromna 8, 20-704 Lublin, Poland

² Faculty of Chemistry, Department of Interphase Phenomena Maria Curie-Skłodowska University in Lublin, Marii Skłodowskiej-Curie 2, 20-031 Lublin, Poland

^{* Corresponding author: robert.waraczewski@up.lublin.pl}

Abstract

This study investigates the microstructural characteristics and surface properties of gels formulated with water, sugar, and glucose-fructose syrup, thickened using gelatin, arrowroot starch, or kudzu starch at concentrations of 2% and 10%. Optical microscopy, confocal laser scanning microscopy (CLSM), and scanning electron microscopy (SEM) were employed to analyze the internal and surface structures of these gels. Surface roughness measurements were conducted to quantify textural differences. The results highlight significant structural variations depending on the type and concentration of the gelling agent used. Gelatin-based gels demonstrate a uniform network structure interspersed with numerous small air bubbles, especially concentrated in the surface foam layer. Despite the presence of air pockets, the overall gel matrix remains homogeneous, suggesting that gelatin’s proteinaceous network effectively stabilizes air incorporation without compromising structural integrity. In contrast, gels prepared with arrowroot and kudzu starches display heterogeneous, wavy structures indicative of localized gelatinization of starch granules, with 10% arrowroot starch gels containing cubic crystals resembling sugar crystals found in crystallized honey. This phenomenon does not occur in 2% starch gels, suggesting a concentration-dependent effect. Surface profilometry reveals that gelatin gels possess smoother surfaces with lower roughness parameters compared to starch-based gels. The smoother surface topology of gelatin gels can be attributed to their cohesive network formation, minimizing surface irregularities, whereas starch-based gels exhibit rougher surfaces due to the uneven swelling and gelatinization of starch granules. SEM analysis confirms these findings, showing that starch-based gels exhibit a fibrous, mesh-like structure reminiscent of frayed fabric, whereas gelatin gels display a more compact and continuous network. These results underscore the significant influence of gelling agents and their concentrations on the microstructural and surface properties of gels, with implications for their functional and sensory attributes in food applications where texture and appearance are critical parameters.

Keywords: hydrocolloids, SEM, microscopy, structure, surface

How to cite

R. Waraczewski, B.G. Sołowiej, K. Terpiłowski, 2025. The structure of starch gels – a microscopic evaluation. In: 4th International PhD Student’s Conference at the University of Life Sciences in Lublin, Poland: Environment – Plant – Animal – Product. https://doi.org/10.24326/ICDSUPL4.F014