Thermophilic 4-α-Glucanotransferase from Thermoproteus Uzoniensis Retards the Long-Term Retrogradation but Maintains the Short-Term Gelation Strength of Tapioca Starch

Abstract

Gelation of starch is a process during short-term retrogradation. However, the long-term retrogradation always leads to the quality deterioration of starch-based food. In this work, a new type of modified tapioca starch (MTS) gel with maintained starch short-term gelation strength and retarded long-term retrogradation was prepared using a novel recombinantly produced and characterized 4-α-glucanotransferase (TuαGT). In the resulting MTS exterior chains of the amylopectin part were elongated and the content of amylose was reduced, due to the disproportionation activity of TuαGT.The retrogradation analysis demonstrated that the MTS possessed highly weakened long-term retrogradation characteristics as compared to the native starch. Most importantly, the strength of the gel formed by re-gelatinized MTS is very close to that of gelatinized native tapioca starch (NTS) when storing below 30°C. These findings provide a starting point for developing a novel method for the enzymatic modification of the starch-based gels.

Maltogenic α-amylase hydrolysis of wheat starch granules: Mechanism and relation to starch retrogradation

“…The sample pans were sealed tightly, and equilibrated over-night. The heating procedure is according to the description of Wang et al (2020). An empty J o u r n a l P r e -p r o o f aluminum pan was used as reference.…”

Impact of Starch Binding Domain Fusion on Activities and Starch Product Structure of 4-α-Glucanotransferase

“…Several 4-α-glucanotransferases have been reported to contain starch binding domains (SBDs) [ 5 , 13 ]. To improve starch affinity and modification for TuαGT, three different fusion proteins were constructed by attaching SBDs of the family CBM20 to the N-terminus of the enzyme.…”

“…The aim of the present work is to confer a thermophilic starch-modifying 4-α-glucanotransferase from Thermoproteus uzoniensis (TuαGT) [ 13 ] with novel functional properties by one-by-one fusion with three different SBDs, two from Solanum tuberosum (potato) disproportionating enzyme 2 ( St DPE2) of the glycoside hydrolase family 77 (GH77) [ 14 ] and one from Aspergillus niger glucoamylase ( An GA) of GH15 [ 15 ]. The effect on the different types of GH77 activities as obtained in the three fusions SBD St1 -TuαGT, SBD St2 -TuαGT, and SBD GA -TuαGT was analysed by using maltotriose, amylose, gelatinised normal and waxy maize starches, and native waxy maize starch granules as substrates.…”

Amylomaltases in Extremophilic Microorganisms

“…Amylomaltases have been therefore employed to produce thermoreversible gels to be used as alternatives to animal gelatin. Enzymes from P. aerophilum [ 11 ], P. calidifontis [ 13 ], T. uzoniensis [ 14 ], T. aquaticus [ 18 ], and T. filiformis [ 22 ] have been assayed for the production of thermoreversible starch gels from different sources (potato, tapioca, corn, rice, cassava, pea), with slightly different properties related to the substrates and relative amylose and amylopectin differential compositions.…”