A novel low-alkali konjac gel induced by ethanol to modulate sodium release

Alcogels have attracted many attentions recently due to their versatile functions and potential applications in developing innovative semi-solid alcohol-containing products. In this study, comparisons were made in the aspect of rheology, physicochemical properties and sodium release between the conventional alkali konjac glucomannan (KGM) gels and alkali KGM alcogels prepared by mixing ethanol with KGM aqueous solution at 0.02 wt%, 0.04 wt% or 0.08 wt% Na2CO3. 20% (v/w) Ethanol could promote the formation of a rigid yet brittle alcogel of KGM with lower dependence of rheological response on frequency and temperature at as low as 0.02 wt% Na2CO3. KGM alcogels were more opaque and constructed by small highly-connected pores, which are 30% smaller in average than those of their counterparts, examined by turbidity and microstructure measurements. Although the swelling ratio of KGM alcogel was only about one third of that of conventional alkali-induced gel, there was about fourfold rise in the amount of Na+ released from alcogels. The release of Nat could be probably regulated by fine-tuning the macro-properties of alcogels through controlling the alkali concentrations.