Characteristics of texture and sucrose release after compression in tapioca starch gels containing sucrose and xanthan gum

Abstract

Importance of the work: The texture of starch gels containing sucrose and hydrocolloids kept in cold storage plays an important role in sucrose release after compression.
Objectives: To characterize tapioca starch (TS) gels containing sucrose and xanthan gum (Xan) on texture and sucrose release after compression.
Materials & Methods: Mixtures were prepared of TS (25% weight per weight) and partial substitution of TS with Xan (0.125, 0.375 and 0.625%) containing sucrose (0–30%) to investigate their impact on retrogradation and the texture of the gels. The sucrose release of all TS/Xan/sucrose gels was determined using a repeated compression test at various speeds (20–500 mm/min) after keeping the gels at 5ºC for certain periods (1–14 d).
Results: Sucrose and Xan retarded the retrogradation of the stored TS gels. Sucrose addition enhanced the fracture stress (σf) and fracture strain (εf) in the TS gels. However, σf decreased and εf increased with increasing Xan content. Sucrose release (reported as total soluble solid after repeated compression) increased with increasing sucrose content and storage time but decreased with increasing compression speed. The number of fragments decreased with increasing sucrose and Xan contents and the compression speed based on image analysis. Sucrose and Xan revealed negative correlations with the retrogradation ratio (correlation coefficient, r = -0.455 and -0.398, respectively, p < 0.01) and positive correlations with fracture strain (r = 0.371 and 0.240, respectively, p < 0.01).
Main finding: The texture and sucrose release in selected starch gel could be modified using sucrose and Xan. The information gained could be applied in product development.