Mechanical properties of inhomogeneous konjac glucomannan gel

Abstract

This study aimed to develop konjac glucomannan gels with novel mechanical properties by modifying the gel network structure. Five types of scallop shell–derived particle gelling agents, with varying particle diameters (1.4 mm < D_a ≤ 4.0 mm, 910 μm < D_b ≤ 1.4 mm, 530 μm < Dc ≤ 910 μm, D_d ≤ 310 μm, and D_e ≤ 150 μm), were used as alternatives to conventional gelling agents (e.g., calcium hydroxide). Konjac gels with an inhomogeneous structure, characterized by cloudy and translucent regions, were obtained using gelling agents with large particle sizes (530 μm < D_a, D_b, and D_c ≤ 4.0 mm). Puncture resistance, surface pH, and internal pH were measured. The cloudy regions exhibited puncture resistance values ranging from 0.63 N to 0.90 N, whereas the translucent regions showed values below the measurement accuracy of 0.05 N. The pH values showed no significant difference (11.62 ≤ pH ≤ 12.34) among all samples regardless of the measurement regions.Although the pH values of the translucent regions were sufficiently alkaline for gel formation, puncture resistance showed markedly low values. Two-bite texture analysis showed distinct mechanical property differences between the inhomogeneous and homogeneous konjac glucomannan gels.