Thermoproteus uzoniensis 4-α-glucanotransferase catalyzed production of a thermo-reversible potato starch gel with superior rheological properties and freeze-thaw stability

Solid-liquid thermo-reversibility, lacking in raw starch is an important property for gels allowing repeated thermal processing food. In this work, the Thermoproteus uzoniensis 4-α-glucanotransferase (TuαGT) was used to modify five different starches from potato, corn, rice, wheat, and pea thermo-reversibility of modified evaluated by rheological assay. Only potato (MPS) exhibited which prompted us perform detailed analyses structural gel properties product. The enzymatic modification resulted a marked decrease amylopectin side chains with degree polymerization (DP) < 23, while contents DP 23–43 increased. These data indicated that TuαGT preferentially extended outer using amylose as donor, 17% increase molecular weight 3.0 × 107 g/mol. Notably, MPS displayed delayed retrogradation improved stability four freeze-thaw cycles (−70 °C 25 °C) compared native starch. supported model explain catalyzed conversion thermo-reversible Importantly, 6% (w/v) showed comparable 1.5% κ-carrageenan hydrocolloid, highlighting potential substitute other hydrocolloids emerging health concerns. This work offers based methodological framework broadens use into novel application food ingredient.