Department of Food Analysis and Evaluation of Food Quality, University of Agriculture in Krakow, Poland.
Department of Food Analysis and Evaluation of Food Quality, University of Agriculture in Krakow, Poland.
Int J Biol Macromol. 2017 Nov;104(Pt A):339-344. doi: 10.1016/j.ijbiomac.2017.06.048. Epub 2017 Jun 8.
This study aimed at analyzing the effect of conditions of modification process on thermal and rheological properties of phosphorylated pumpkin starch. The esterification process was conducted at 115°C and 145°C for 1, 2, and 3h. The thermodynamic properties of samples were determined using differential scanning calorimetry (DSC), flow curves were plotted and the resulting curves were described the Herschel-Bulkley model, textural properties were evaluated with the TPA method. The data proved that the chemical modification of starch affected its rheological and thermal characteristics, but the direction and extent of the changes were found to depend on both temperature and duration of phoshorylation. The results demonstrated that temperatures of gelatinization of the samples modified at 145°C were higher by 1.4-8.5°C than those of the samples obtained at 115°C. Prolongation of starch modification at 115°C caused reduction of shear stress (from 2.10Pa to 0.86Pa), and higher temperature of esterification also reduced the value of this parameter. The hardness of the samples heated at 145°C was higher by 45-59N than that of heated at 115°C. Adjustment of phosphorylation process caused an increase in gumminess by 1.8-37.9N, wherein higher temperature and process prolongation resulted in the highest gumminess.
本研究旨在分析改性条件对磷酸化南瓜淀粉热性能和流变性能的影响。酯化过程在 115°C 和 145°C 下进行 1、2 和 3 小时。使用差示扫描量热法 (DSC) 测定样品的热力学性质，绘制流动曲线，并使用 Herschel-Bulkley 模型描述所得曲线，使用 TPA 方法评估质构特性。数据表明，淀粉的化学改性影响其流变和热特性，但变化的方向和程度取决于磷酸化的温度和时间。结果表明，在 145°C 下改性的样品的胶化温度比在 115°C 下获得的样品高 1.4-8.5°C。在 115°C 下延长淀粉改性时间会导致剪切应力降低（从 2.10Pa 降低至 0.86Pa），而酯化温度升高也会降低该参数的值。在 145°C 下加热的样品的硬度比在 115°C 下加热的样品高 45-59N。通过调整磷酸化过程，胶粘性增加了 1.8-37.9N，其中较高的温度和较长的处理时间导致胶粘性最高。
