This study aimed to investigate the effects of the proportion of konjac in a blend of konjac and secondary gum (κ-
carrageenan and xanthan) from 25:75 to 50:50 and the levels of sweeteners (sucrose at 2-20% (w/v) and erythritol-sucralose
at 0.2-2.5% (w/v)) on the firmness of konjac gels using response surface methodology. The variation in the proportion of
konjac greatly affected the gel firmness with respect to the sweetener. Increasing the konjac proportion increased the
firmness of the konjac gels that were co-gelated with either of the secondary gums. At a high konjac proportion, an addition
of 2-11% sucrose increased the firmness of the konjac/κ-carrageenan gel but decreased that of the konjac/xanthan gel. The
addition of erythritol-sucralose had a small effect on the konjac gel firmness. Predicted models of konjac gels were reliable
and can be used to optimize the conditions that provided the greatest firmness. The optimal conditions were found to use the
konjac/secondary gum at approximately 50:50 with 17% sucrose or 2.5% erythritol-sucralose for the konjac/κ-carrageenan
gel and with 2% sucrose or 0.76% erythritol-sucralose for the konjac/xanthan gel.
