Abstract Two wet-end starches (potato and barley), one surface sizing starch (barley) and one coating binder starch (barley) were jet-cooked. Samples were collected and stored at 90, 60 and 40 °C. 1H NMR-relaxometry and viscometry were used to monitor the jet-cooked solutions as they cooled to room temperature. Samples stored at different temperatures were also monitored using 1H NMR-relaxometry and viscometry. A sediment formed into the surface sizing and coating binder starches stored at 90 °C. The sediment and supernatant were separated and collected, and measured using 1H NMR-relaxometry. The T 2 {T_{2}} relaxation rates of jet-cooked starches showed significant differences between potato and barley starches, as had also been examined in previous studies. The NMR method was also sensitive to differences in solids content and chemical modification (degree of cationization, degree of oxidation and molecular weight). The cooking temperature, cooking speed and viscosity did not influence T 2 {T_{2}} relaxation rates. The sediment separated from the surface sizing and coating binder starches held at 90 °C had a significantly higher relaxation rate than the supernatant, indicating that the sediment contained a high amount of retrograded starch.

中文翻译：

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使用 1H NMR-弛豫测定法和粘度测定法研究喷射蒸煮造纸淀粉

摘要 对两种湿部淀粉（马铃薯和大麦）、一种表面施胶淀粉（大麦）和一种包衣粘合剂淀粉（大麦）进行喷射蒸煮。收集样品并在 90、60 和 40 °C 下储存。当喷射蒸煮溶液冷却至室温时，使用 1 H NMR-弛豫测定法和粘度测定法来监测它们。还使用 1 H NMR-弛豫测定法和粘度测定法监测在不同温度下储存的样品。沉积物形成在 90 °C 下储存的表面施胶和涂层粘合剂淀粉。分离并收集沉淀物和上清液，并使用 1 H NMR-弛豫测定法进行测量。喷射蒸煮淀粉的 T 2 {T_{2}} 弛豫率显示出马铃薯和大麦淀粉之间的显着差异，这在之前的研究中也得到了检验。NMR 方法对固体含量和化学改性（阳离子化程度、氧化程度和分子量）的差异也很敏感。蒸煮温度、蒸煮速度和粘度不影响T 2 {T_{2}} 弛豫率。与保持在 90 °C 的表面施胶和涂层粘合剂淀粉分离的沉积物的松弛率明显高于上清液，表明沉积物含有大量的回生淀粉。