Co-effect Of Salt And Sugar On The Functional Properties Of Starch

Food additives (salt/sugar) will produce a great effect on the functional properties of starch, especially when they co-exist with other ingredients in many food formulations.This investigation, therefore, undertook a systematic study of the effect of salt and/or sugar on the functional properties of rice and chestnut starch.Salt/sugar can reduce the water activity and inhibit the swelling of starch granules during the heating process, especially the effect of salt is significant. When the two additives co-exist, they play a compound effect on starch.Differential scanning calorimetry (DSC) demonstrated that salt or sugar addition significantly increased gelatinization temperatures of either rice starch or chestnut starch,whereas gelatinization enthalpy was less affected. When salt coexist with sugar, their effect on gelatinization property is greater than the individual. However, using infrared spectroscopy (FTIR) investigate that the salt and sugar on the short-range order of starch shown no siginificant effect. The confocal Raman spectrometer (Raman) and X-ray diffraction (XRD) found that the results in agreement with findings of the DSC. which is due to the inhibition of salt and sugar on starch.Salt or sugar can inhibit the aging progress as the enthalpy is decreased. Their co-effect is more pronounced than that of the alternative.Rapid visco-analysis (RVA) showed that addition of salts significantly decreased peak,breakdown, and setback viscosities, increased trough and final viscosities, whereas those of rice/sugar blends were varied depending on the concentration of sugar added.When the sucrose concentration reached 10%,the peak viscosity of rice starch decreased then increased, followed by the increase of sucrose concentration and the trough viscosity(except 25% sugar concentration).The co-effect on viscosity is consistent with the individual salt effect. The addition of NaCl will decrease the peak and breakdown viscosities, increase the trough and final viscosities while the setback is less affected.Sucrose enhanced cold paste stability of chestnut starch. The co-effect of NaCl and sucrose is much more like the individual salt effect.Salt can increase the gel hardness, chewiness and gumminess. With the increase of salt concentration, the effect is more obvious. The springiness, cohesiveness and resilience remain unchanged. Effect of sugar on gel quality of rice starch is not significant. The effect of salt and sugar is consistent with that of only salt effect.The in vitro enzyme digestibility assay showed that the addition of salt/sugar had no significant effect on the hydrolysis of the starch while the combination of the two additives showed promotation effect.