Deacetylation-induced aggregates of konjac glucomannan: Evaluating its potential as food emulsifier

As an excellent textural regulator as well as health promoter, Konjac glucomannan (KGM) demonstrates promising potential for the development of functional foods. This study proposes that deacetylation-induced aggregates of KGM, with enhanced amphiphilicity and altered morphological properties, exhibit potential in stabilizing oil-in-water emulsions. Deacetylated KGM aggregates (DKs) were prepared via alkaline-thermal treatment, and the deacetylation degree could be regulated by alkali concentration. Analysis of Zeta-potential, deacetylation degree, and FT-IR spectra collectively confirm that KGM aggregation is driven by the removal of acetyl groups. Physical properties of DKs were characterized by visual appearance, microscopic morphology, rheological behavior, and three-phase contact angle. Results reveal that appropriate deacetylation (27.26 %) induces molecular-scale aggregation of KGM, which enhances amphiphilicity while preserving the viscosity of DKs suspensions. Emulsification assays indicate distinct interfacial stabilizing mechanism between KGM and DKs. Attributed to higher viscosity and better interfacial adsorption, DK-6 (27.26 % deacetylation) suspensions could ensure the long-term stability, thermal stability, and NaCl tolerance of emulsions. By clarifying the emulsifying potential of DKs, this study offers novel perspectives for developing polysaccharides-based food emulsifiers.