| Native potato starch, which is used in the food, paper and textile industries, is often not optimal for a particular application. However, modifications are done to obtain the properties needed for specificuses. In this paper, we studied the potato starch/hydrocolloids combinations, which need in food thickeners and stabilizers to improve food security and be instead of modified starches. Interactions and application in ketchup were also studied. The main contents are as follows:The activity of guar gum and xanthan gum on properties of native and modifiled potato starch were studied. The ionic interactions were found to play an important role. Guar gum enhanced peak viscosity of three kinds of starch. Xanthan gum dropped peak viscosity of native and anionic potato starch, but improved cationic potato starch. Compared to guar gum, Xanthan gum was more pronounced for improving stabilities of starch paste under heating, viscoelastic, psecdoplastic, shear stability and strengthening the network structure of starch. So the main study was focused on the interaction between potato starch and xanthan gum.The effects of electrostatic interactions on mechanism of potato starch/xanthan gum combinations were investigated. The peak viscosity of combinations was decreased firstly and then increased with adding of xanthan. The analysis and regression model performance of measurement showed there was the relationship between pasting properties of combinations and xanthan concentrations. Electrostatic repulsions between potato starch or anionic potato starches and xanthan could be present by decreasing peak viscosity, pasting temperatures showed increasing. But electrostatic attractions between cationic potato starch and xanthan showed opposite effect. Negative zeta potential determination for combinations was higher than potato starch illustrated combinations had more electronegativity and stability, a phase-separated microstructure was exhibited. Particle size analysis, LEM, DSC, and SEM presented xanthan film attached to the surface of starch, which inhibited granules destruction and leaching of amylase, resulting pasting temperature improved. The electrostatic repulsions leaded to more stability of three dimensional network structures of combinations.By studying the effects of food environments on potato starch/xanthan, the combinations had anti-acid and anti-shear capacity; Different types and concentrations of salt influenced properties of combinations. Interactions of ions leaded the effect of CaCl2 more obviously.The potato starch/xanthan combinations as a ketchup thickening stabilizer results showed combinations significantly improved hardness, cohesive, adhesive, storage stability,dispersion smearing. Therefore, combinations were suitable for ketchup and reduced production costs. |
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