Effect of salt addition on gelatinization and rheological properties of sweet potato starch–xanthan gum mixture

Abstract

The effect of NaCl at different concentrations (1.0–5.0%) on the gelatinization and rheological properties of sweet potato starch (SPS)–xanthan gum (XG) mixtures was examined. Steady shear rheological properties of SPS–XG–NaCl mixtures were determined from the rheological parameters for the power law and Casson flow models. The consistency index (K), apparent viscosity (ηa,100,), and Casson yield stress (σoc) values of SPS–XG–NaCl mixtures were much lower than those of the control (0% NaCl) and also decreased with an increase in the NaCl concentration. The storage modulus (G′) values of SPS–XG–NaCl mixtures were much higher than the loss modulus (G″), indicating that the addition of NaCl influences the synergistic effect in the elastic properties of XG in the SPS–XG–NaCl mixture systems. The addition of NaCl resulted in a significant increase in the peak, breakdown, final, and setback viscosities, and pasting temperature of SPS–XG mixture. In general, differential scanning calorimeter (DSC) studies conveyed that the presence of NaCl resulted in an increase in the gelatinization temperatures (To, Tp, and Tc) and a decrease in gelatinization enthalpy (ΔH). In general, these results suggest that the addition of the NaCl to SPS–XG mixtures modified the pasting, rheological, and thermal properties, depending on the NaCl concentration.

Effects of Acid and Salt Solutions on the Pasting, Rheology and Texture of Lotus Root Starch–Konjac Glucomannan Mixture

“…The tan δ of LRS/KGM mixtures at the various NaCl concentrations was similar but lower than that of the unsalted system. The minimum tan δ value was achieved at a 0.5 mol/L NaCl concentration, indicating that the 0.5 mol/L NaCl solution can increase the proportion of elasticity in the LRS/KGM mixture, likely due to the induction of KGM molecular aggregates by NaCl, in agreement with a previous study concerning the effects of NaCl on the rheology of a sweet potato–xanthan gum mixture [15]. Moreover, tan δ increased continuously with the increase in KCl, exceeding that of the unsalted system at 1 mol/L.…”

“…Therefore, LRS/KGM mixtures at this ratio were used for all subsequent experiments. With reference to the method of Gil and Yoo [ 15 ], with slight modifications, the analysis of pasting properties was performed using the Rapid Visco Analyzer (RVA-TecMaster, Perten Instruments, New South Wales, Australia) with a RVA aluminum box. Firstly, the solutions were adjusted to pH 3 and 7 using citric acid-containing phosphate buffer, then weighed LRS/KGM was then mixed with the solutions in an aluminum box, forming a 6 g/100 g (mass fraction) suspension, to determine the effect of pH on the LRS/KGM system.…”

“…Moreover, in many food production processes, starch/hydrophilic colloid mixtures are often used in acid and salinity environments that significantly affect the mixture properties. Significant effects of salt on the gelatinization and viscosity of a corn starch–guar gum mixture and sweet potato starch–xanthan gum mixture, according to the salt type and concentration, have been observed [ 15 , 16 ]. Various studies have also highlighted that salts exert a great influence on the gelatinization, thermodynamics, and rheological properties of a rice starch/hydrophilic colloid mixture [ 17 , 18 ].…”

Synergistic rheological behavior and morphology of yam starch and Auricularia auricula-judae polysaccharide-composite gels under processing conditions

“…2(B indicating that the YA gels became less pseudoplastic. Similar tendencies were observed in studies of sweet potato starch and xanthan mixtures [6]. The data indicated the synergistic interaction between AP and YS could be controlled by added NaCl, probably because of the more compact conformation of hydrocolloid molecular chains caused by charge-screening effects, resulting in a reduction in hydrodynamic size and a difficulty in forming intermolecular associations [30].…”

“…guar gum, xanthan, chitosan, or xyloglucan) on the pasting, gelatinization, retrogradation, and digestibility of composite systems [2][3][4]. In addition to their physicochemical characteristics, detailed knowledge concerning the roles of hydrocolloid interactions on rheological properties associated with specific functionalities of starch paste is also crucial for developing their potential for industrial applications [5][6][7][8].…”