The Effect of Glucose Syrup on Rheological Properties of Sago Starch

Abstract

The effect of glucose syrup on the rheological properties of sago starch was examined. The glucose syrup (30 - 75 g) was mixed with sago starch 100 g and baked at 60 °C for 16 h. The sago starch formulas 1 - 10 were analyzed rheological properties using a strain sweep test for evaluated Linear Viscoelastic Range (LVR) used for studied temperature test and frequency test. The result showed that the G’ values of the sago starch formulas 1 - 10 decreased respectively which indicated an increase in the amount of glucose syrup resulting in the storage modulus within the starch structure decreasing causing agglomeration. In addition, in the temperature range of 70 - 95 °C, the sago starch formula 1 - 10 began to gelatinize and then stabilize. It indicated that the sago starch slurry was more similar to the solid. When the temperature was lowered from 95 to 30 °C, the G’ and G” values of the sago starch formulas 1 - 10 gradually increased and then decreased because the starch solution during heating is agglomerated into large particles. The flexibility of solids within the powdery structure is very high and very viscous, so that during the initial decrease in temperature, the G’ and G” values increase. After a while, when the temperature inside the structure begins to decrease, which causes the value of G’ and G” to decrease. In the analysis of texture characteristics of the sago starch formulas 1 - 10, it was found that Hardness, Gumminess and Chewiness decreased significantly as the ratio of glucose syrup was increased in the formulations of the sago starch. The lower hardness value of the sago starch formulation with more added content of glucose syrup. Adhesiveness, cohesiveness and springiness values were not different between all the sago starch formulations. HIGHLIGHTS Rheological properties of the sago starch formulas showed that more glucose syrup mixed with sago starch, increased viscoelastic behavior because when increasing the frequency, there will be a value G' > G'' The different textures of the sago starch formulations indicated the basic action of glucose syrup on the microstructure of the sago starch The differences in rheological properties and texture of the sago starch formulas are the reasons for choosing different filling ratios of sago starch and glucose syrup for cooking GRAPHICAL ABSTRACT