Improving the gel properties of Ficus pumila Linn. pectin by incorporating deacetylated konjac glucomannan.

To improve the gelation behaviour of pectin, the effect of deacetylated konjac glucomannan (DKGM) with various deacetylation degrees (27.44 %, 44.32 %, 60.25 %, and 71.77 %) on the heat-induced gel characteristics of Ficus pumila Linn. pectin was studied. The hardness, chewiness, and adhesiveness of the gel increased as the degree of deacetylation increased from 27.44 % to 60.25 %, but decreased at 71.77 %. Additionally, DKGM addition resulted in higher apparent viscosity and non-Newtonian fluid behaviour in the composite gel. The incorporation of DKGM into the gel matrix strengthened the gel structure by promoting hydrogen bond formation and shortening relaxation time compared to the control. Scanning electron microscopy images revealed that the densification of the pectin gel network increased as the degree of deacetylation of konjac glucomannan rose from 27.44 % to 60.25 %, but then loosened when it exceeded 71.77 %. As the degree of deacetylation increased, the hydrophobic interaction between pectin and DKGM increased. Overall, the addition of DKGM effectively modulated the gel properties of Ficus pumila Linn. pectin, thus broadening its industrial application on different gel products.