Effect of Glutamine Transaminase on Physicochemical Properties of Chestnut Flour Dough

Abstract

The effect of glutamine transaminase (TG) addition at varying concentrations (0, 0.9, 1.8, 1.8, 2.7 and 3.6 U/g, based on the total mass of chestnut flour) on the texture, rheological, and gelatinization characteristics of chestnut flour dough was investigated and analyzed in terms of changes in the content of free sulfhydryl groups and the microstructure of chestnut dough was observed via a scanning electron microscope (SEM). The results showed that the incorporation of TG resulted in enhanced viscosity, hardness, elasticity, chewiness, and resilience of chestnut dough. Compared with the blank control group, the addition of TG at 2.7 U/g increased the final viscosity by 6.8 cP, hardness by 7.55 g, elasticity by 0.38, chewiness by 33.62 g, and resilience by 0.118, leading to a more stable internal structure. As TG addition increased, both the elastic modulus and viscosity modulus of chestnut dough showed an upward trend, contributing to an improvement in viscoelasticity. This enhancement strengthened the dough’s resistance to deformation and consequently improved its stability and processing performance. The content of free sulfhydryl groups in chestnut dough decreased with increasing TG addition, and decreased by 0.16 mmol/g at 2.7 U/g compared with the blank control group. However, it was observed that excessive TG addition led to excessive protein cross-linking, exposure of starch particles, and a subsequent reduction in the overall stability of the dough. This study suggests that the addition of 2.7 U/g of TG has the most pronounced effect on enhancing the physicochemical properties of chestnut dough.

Keywords

• chestnut powder; dough; glutamine transaminase; food texture; physicochemical properties