Facile post-gelation soaking strategy toward low-alkaline konjac glucomannan gels

A facile post-gelation soaking strategy for producing low-alkaline konjac glucomannan (KGM) gels was investigated in this work. The dealkalization kinetics of soaking alkali-induced gels in citric acid (CA) solutions was determined. A comparison of sensory, textural, and water holding properties was made between untreated and post-soaking gels. Post-gelation exposure to acid took less time for lowering the gel pH at higher CA concentrations, eliminated the unattractive flavor of KGM gels and endowed them a higher hardness and breaking force. Comparatively, the whiteness of post-soaking gels was increased by 3.8%-13.1% with volume being decreased by 4.9%-8.6%, while the discrepancies were less apparent after a long-term storage. Low-alkaline gels treated by 4 g/L CA shared similar textural features with conventional KGM gels. Despite the difference in water distribution and water holding capacity of KGM gels, the syneresis of resultant low-alkaline KGM gels was not significantly affected.

Automated summary

A facile post-gelation soaking strategy was investigated in this study to produce low-alkaline konjac glucomannan (KGM) gels. The process involved soaking alkali-induced gels in citric acid (CA) solutions, which successfully reduced the gel pH and improved the texture and flavor of the gels. The whiteness of the gels increased and the volume decreased after post-soaking treatment, but these differences became less apparent after long-term storage. The water holding capacity and syneresis of the low-alkaline KGM gels were not significantly affected by the soaking process.