Partial removal of acetyl groups in konjac glucomannan significantly improved the rheological properties and texture of konjac glucomannan and κ-carrageenan blends

• Published in: International journal of biological macromolecules Vol. 123; pp. 1165 - 1171
• Main Authors: Hu, Yan, Tian, Jing, Zou, Jian, Yuan, Xiaoqing, Li, Jing, Liang, Hongshan, Zhan, Fuchao, Li, Bin
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.02.2019
• Subjects: Deacetylated konjac glucomannan; Gel; κ-Carrageenan; κ-Carrageenan; Deacetylated konjac glucomannan; Gel
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2018.10.190

The main aim of the current study was to research the effect of the degree of konjac deacetylation on the rheological and textural properties of konjac glucomannan (KGM) and κ-carrageenan blends. A series of deacetylated konjac glucomannan (Da-KGM) with different degrees of deacetylation (0, 20.35%, 35.62%, 57.19%, and 74.01%) was prepared by a heterogeneous deacetylation method. The rheological and textural properties of mixed sols and gels of Da-KGM with different degrees of deacetylation and κ-carrageenan were determined. The results showed that the viscosities of mixed sols of Da-KGM and κ-carrageenan decreased with increasing degree of deacetylation. The partial removal of acetyl groups from konjac glucomannan could significantly improve the hardness and springiness of mixed gels of KGM and κ-carrageenan. Meanwhile, decreasing the acetyl content could decrease the syneresis of mixed gels. By regulating the deacetylation degree of konjac, gels with high gel strength could be prepared, which provides a new idea for the production of high-strength gelatin food. [Display omitted] •The viscosities of mixed sols of Da-KGM/κ-carrageenan decreased with the increasing of deacetylation degree.•Partial removal of acetyl groups could significantly improve hardness and springiness of KGM/κ-carrageenan mixed gels.•The decreasing of acetyl content could help to the decreasing of the syneresis of mixed gels.•By regulating the degree of deacetylation of konjac, the gel with high gel strength could be prepared.