Improving the edible quality of deacetylated konjac glucomannan gel: Synergistic ethanol immersion and low-temperature pretreatment

Abstract

Solvent exchange approach and low-temperature treatment are both promising strategies that can be applied to improve hydrogel-based food quality. This study investigated the synergistic effect of different ethanol concentrations (15 % to 75 %) in combination with 4 °C refrigeration and − 20 °C freezing on the physical properties and edible attributes of deacetylated konjac glucomannan gel (DKG). The physical properties of DKG include hydration capacity, network strength, and pore size, while the edible attributes primarily include textural properties, chroma, pH, flavor profile, and sensory evaluation. Ethanol immersion and low-temperature treatment changed the water distribution and proportion, decreased pore size, and led to a more compact structure in DKG. Combined application of low concentration ethanol soaking (35 %) and freezing (−20 °C) effectively enhanced hardness and inhibits the dehydration shrinkage of DKG (inhibition rate = 71.34 %). Ethanol soaking and low-temperature treatment improved the DKG color, facilitated the absorption of flavor compounds, and enhanced consumer acceptance. Current results highlight the potential of ethanol synergized with low-temperature treatment as a simple and effective method to improve konjac edible quality and consumer appeal. Our findings provide insights into improving the physical properties of konjac hydrogel and offer a reference for expanding the practical application of konjac-based products.