皂荚糖胶对玉米淀粉老化性质的影响及体系的水分分布

以玉米淀粉为原料，用流变分析、食品物性分析、差示扫描量热分析、低场核磁共振成像分析等研究冷藏过程中不同含量（相对玉米淀粉干基质量的1%、3%、5%和7%）皂荚糖胶对玉米淀粉老化特性的影响。动态流变时间扫描结果表明：随着老化时间的延长，玉米淀粉的弹性模量增加，皂荚糖胶的加入使复配体系弹性模量的变化率减小，一定程度上抑制玉米淀粉的短期老化；凝胶强度实验表明：随着冷藏时间的延长，玉米淀粉凝胶体系的硬度值增加，皂荚糖胶的加入使玉米淀粉形成质地更柔软的凝胶，硬度值明显降低；差示扫描量热测定结果表明：随着皂荚糖胶含量的增加，复配体系的老化率逐渐减小。用低场核磁水分运动性实验方法，通过5%皂荚糖胶加入前后淀粉凝胶中自由水、结合水和不易流动水含量的对比证实该胶对凝胶的水分分布有较大的影响；该研究能进一步丰富植物胶体对淀粉老化性能影响的理论。

Effects of Gleditsia sinensis Lam. Gum on the Retrogradation Properties of Corn Starch and Water Distribution in Mixture Systems

The effect of Gleditsia sinensis Lam. gum (GSLG) added in different proportions (1%, 3%, 5% and 7%, based on the dry mass of corn starch) to corn starch on its retrogradation during cold storage (CS) was investigated in this study by rheological and texture characterization, differential scanning calorimetry (DSC) and low-field nuclear magnetic resonance (LF-NMR) imaging analysis. Dynamic rheological analysis showed that the elastic modulus of corn starch increased with refrigeration time; addition of GSLG decreased the change in elastic modulus and inhibited the short-term retrogradation of corn starch to some extent. The hardness of starch gels increased with cold storage time but decreased with the addition of GSLG. The results of DSC showed that the aging rate of mixed systems decreased with increasing addition of GSLG. Using LF-NMR, a comparative analysis of the proportions of free, bound, and immobile water in starch gels before and after addition of 5% GSLG was conducted, which confirmed that the gum had a large effect on the water distribution in the gels. This study further enriches the theoretical understanding of the effect of plant gums on the aging property of starch.