慈姑、荸荠和菱角淀粉共混物的凝胶特性研究

Gel Characteristics of Starch Blends from Sagittaria sagittifolia, Eleocharis dulcis and Trapa natans

慈姑、荸荠和菱角均为南方特色水生根茎类作物,具有独特的加工特性,其混粉制品拥有新的凝胶特点和营养价值。本试验采用混料设计,建立了凝胶质构指标与混合淀粉各组分的回归模型,并采用差示扫描量热法测定混粉糊化过程中的热特性,在二者基础上探讨各组分间的交互作用。结果表明,混粉既表现出慈姑淀粉的拮抗效应,也表现出菱角淀粉的增效效应,这两种作用相互制约,最终在各凝胶质构特征参数上表现出占优势的一种。DSC图中吸热峰的叠加,表明混合淀粉发生了共糊化。慈姑、荸荠淀粉的存在,明显抑制了菱角淀粉的回生,菱角淀粉颗粒相对可利用的水分少,膨胀受限,仅能部分膨胀,贮藏过程中的脱水收缩作用减弱。模型的建立对于优化各淀粉组分比例而获得所需的凝胶特性具有指导意义,该研究可为南方特色淀粉资源的有效利用提供参考。

Sagittaria sagittifolia, Eleocharis dulcis and Trapa natans are chief aquatic rhizomatous crops in southern China. Their proper combination can create novel food products with new texture and nutritional values. In the paper, mixture design approach was used to investigate the effects of the composition of these three starches on the textural properties of gels, and to characterize the gelatinization process of different starch blends ratio by using differential scanning calorimetry （DSC）. The results showed that the mixture starches presented antagonistic effect for Sagittaria sagittifolia starch and synergistic effect for Trapa natans starch. These two actions interacted and finally displayed the antagonistic effect on hardness, cohesiveness, elasticity, consistency and chewiness, but not on adhesiveness. The DSC results indicated that components of the mixture dependently gelatinized, as evidenced by the two endothermic peaks corresponding to the individual components. The starches of Sagittaria sagittifolia and Eleocharis dulcis inhibited the recovery of Trapa natans starch, which led to less swelling of the starch granules. The research can provide a reference for efficient use of special starches from southern China.