A Comparative Evaluation of the Structural and Biomechanical Properties of Food-Grade Biopolymers as Potential Hydrogel Building Blocks

Abstract

The aim of this study was to conduct a comparative assessment of the structural and biomechanical properties of eight selected food-grade biopolymers (pea protein, wheat protein, gellan gum, konjac gum, inulin, maltodextrin, psyllium, and tara gum) as potential hydrogel building blocks. The prepared samples were investigated in terms of the volumetric gelling index, microrheological parameters, physical stability, and color parameters. Pea protein, gellan gum, konjac gum, and psyllium samples had high VGI values (100%), low solid–liquid balance (SLB < 0.5), and high macroscopic viscosity index (MVI) values (53.50, 59.98, 81.58, and 45.62 nm−2, respectively) in comparison with the samples prepared using wheat protein, maltodextrin, and tara gum (SLB > 0.5, MVI: 13.58, 0.04, and 0.25 nm−2, respectively). Inulin had the highest elasticity index value (31.05 nm−2) and MVI value (590.17 nm−2). The instability index was the lowest in the case of pea protein, gellan gum, konjac gum, and inulin (below 0.02). The color parameters and whiteness index (WI) of each biopolymer differed significantly from one another. Based on the obtained results, pea protein, gellan gum, konjac gum, and psyllium hydrogels had similar structural and biomechanical properties, while inulin hydrogel had the most diverse properties. Wheat protein, maltodextrin, and tara gum did not form a gel structure.

Binary Pea Protein–Psyllium Hydrogel: Insights into the Influence of pH and Ionic Strength on the Physical Stability and Mechanical Characteristics

“…The destabilization front moved downward in the sample, meaning that the highest particle concentration was at the bottom of the sample. At the same time, a transparent water phase remained in the upper parts [ 50 , 51 ]. Based on the transmission profiles, it is possible to conclude that the slowest destabilization changes occurred in the hydrogel induced at pH 7 (without the addition of salt).…”

“…The VGI equals zero when no gel structure is formed and 100% when the sample is completely gelled. The VGI is calculated using the equation below [ 50 ]. where V G —volume of the formulated gel and V T —total volume of the sample.…”

“…SLB is the ratio (G’/G”) of the elastic modulus to the viscous modulus. The reciprocal of the MSD value at the plateau is used to calculate EI, which is directly proportional to the elastic modulus (G’) [ 50 , 66 ]. The values that are reported are the averages of three replicates.…”

“…The VGI equals zero when no gel structure is formed and 100% when the sample is completely gelled. The VGI is calculated using the equation below [50].…”

Assessment of the Physicochemical and Textural Properties of Food Hydrogels Obtained Using Pea Protein and Gellan Gum

“…Hydrogels have emerged as an essential component in food applications, offering many benefits when developing new functional food systems. These food hydrogels' significant potential properties are related to their distinctive three-dimensional structure, composed of hydrophilic polymers capable of absorbing and retaining large amounts of water [1,2]. They provide several valuable features when developing new food systems, including moisture retention, structure stability enhancement, and textural attribute enhancement (including emulating the mouthfeel and texture of fats while significantly reducing caloric content when used as fat mimetics) [3][4][5].…”