Department of Food Science and Technology, Chaudhary Devi Lal University, Sirsa, India.
Department of Food Science and Technology, Chaudhary Devi Lal University, Sirsa, India.
Int J Biol Macromol. 2020 Aug 15;157:584-590. doi: 10.1016/j.ijbiomac.2020.04.181. Epub 2020 Apr 25.
Native and gamma (γ) irradiated lotus seed starches were studied for their physicochemical, thermal, pasting and morphological properties. Upon gamma irradiation of 5, 10, 15 and 20 kGy, amylose content of starches was decreased as the dose of irradiation was increased. Lotus seeds starch granules had bimodal size distribution varying in size from small to large. Observation under scanning electron microscope (SEM) showed that at low dose of irradiation (5, 10kGy), no significant changes were observed in shape and size. However, minor alterations were notice during treatment of 15kGy and 20 kGy, which included roughness. Irradiation significantly decreased the pasting properties (peak, trough, final and setback viscosities) of the starch. For native starch, T, T, and T of 137.44 °C, 138.29 °C and 143.21 °C and 169.51 °C, 169.72 °C, and 177.73 °C respectively was observed for first and second peak. Upon irradiation, the gelatinization temperatures were decreased. The irradiated starch showed no change in diffraction pattern compared to native lotus seed starch but a dose-dependent decrease in relative crystallinity was observed.
天然和γ辐照的莲子淀粉的物理化学、热学、糊化和形态特性进行了研究。随着辐照剂量从 5、10、15 增加到 20 kGy，淀粉的直链淀粉含量逐渐降低。莲子淀粉颗粒的粒径分布呈双峰分布，从小变大。扫描电子显微镜（SEM）观察表明，在低剂量辐照（5、10 kGy）下，形状和大小没有明显变化。然而，在 15 kGy 和 20 kGy 的处理过程中，观察到了轻微的变化，包括粗糙度。辐照显著降低了淀粉的糊化特性（峰值、低谷、最终和回生黏度）。对于天然淀粉，分别观察到 137.44°C、138.29°C 和 143.21°C 的 T 1、T 2 和 T 3，以及 169.51°C、169.72°C 和 177.73°C 的 T 1 和 T 2。在辐照后，凝胶化温度降低。与天然莲子淀粉相比，辐照淀粉的衍射图谱没有变化，但相对结晶度呈剂量依赖性降低。
