| In this study, different kinds of salts, including halogen anion salts (NaF, NaCl, NaBr, Nal), other anion salts (K2SO4, KC1, KNO3, KSCN) and different cation salts (KCl, NaCl, LiCl), were added into potato starch, maize starch and waxy maize starch to investigate the influence of these nine salts on the gelatinization (swelling power, solubility, the particle size distribution, granular structures and DSC analysis) properties of these starch granules, and retrogradation (the transparency, syneresis, freeze-thaw stability, textural and rheological) properties of these starch gels systematically in according with the Hofmeister series. The main results were as shown below:(1) The influence of these nine kinds of salts additives on the solubility, swelling power, the particle size distribution, and granular structures, pasting properties of potato starch, maize starch and waxy maize starch granules were assessed. It showed that the salting-out ions decreased the solubility, swelling power, the particle size markedly (p<0.05) and increased the gelatinization temperature and△H of these starches during gelatinization. While the salting-in ions increased the solubility, swelling power, the particle size and decreased the gelatinization temperature and△H of these starches during gelatinization significantly (p<0.05). The tendency of starch gelatinization from easy to hard is:potato starch, waxy maize starch and maize starch.(2) The transparency of potato starch, maize starch and waxy maize starch paste decreased with the addiing of salting-out ions markedly (p<0.05), while, increased with the salting-in ions significantly (p<0.05). The transparency decreased with the extension of storage time. Due to starches’different properties, the transparency of potato starch is the highest, waxy maize starch is the second, while maize starch is the lowest.(3) The syneresis and freeze-thaw stability of potato starch, maize starch and waxy maize starch pastes have a strong relationship with the degree of starch retrogradation. Salting-out ions accelerated the retrogradation of starch, causing an increase of water amount separated from the system; while salting-in ions inhibited the retrogradation of starch, causing a decrease of water amount separated from the system. The tendency of starch retrogradation from easy to hard is:maize starch, potato starch and waxy maize starch.(4) The TPA properties of potato starch gels were significantly influenced by salts. The salting-out ions increased the hardness, gumminess and chewiness significantly (p<0.05), while, the salting-in ions decreased the hardness, gumminess and chewiness significantly (p<0.05). The puncture performance’s result was consistent with that of TPA of potato starch gels.(5) The addition of salts had no influence on the trend of starch system’s G’ and G" according to the dynamic rheological analysis. The PeakG’and PeakG" decreased with the addition of salting-in ions, while increased with the addition of salting-out ions.(6) The power-law equation (τ=kγn) fitted the shear stress-shear rate curve of all samples (potato starch gels) well with R2>0.9986. Because n<1, so samples all belonged to the pseudoplastic fluid. The area of hysteresis loop decreased with the addition of salting-out ions while increased with the addition of salting-in ions.(7) All samples (potato starch gels) showed shear-thinning property according to the viscosity-shear rate curve. The addition of salting-in ions were able to decrease the viscosity, while the adding of salting-out ions were able to increase the viscosity at the same shear rate. |
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