School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China.
Whistler Center for Carbohydrate Research, Department of Food Science, Purdue University, 745 Agriculture Mall Drive, West Lafayette, IN 47907, USA.
Int J Biol Macromol. 2021 Jul 1;182:65-71. doi: 10.1016/j.ijbiomac.2021.03.195. Epub 2021 Apr 5.
Three different storage temperatures including room temperature (RT), 4 °C and -20 °C were investigated in this study, with respects to their effects on the retrogradation property and in vitro digestibility of gelatinized sago starch. Storage at -20 °C resulted in the highest amount of both intra- and intermolecular double helices and a fracture-like structure under scanning electron microscopy (SEM). These crystallites were more homogenous while less thermally stable than that from RT and 4 °C storage conditions. Storage at RT significantly increased the stability and heterogeneity of the formed crystallites, resulting in a sponge-like structure under SEM. Causally, the digestion rate of retrograded sago starch by α-amylase was significantly lowered after storage at -20 °C compared to that at RT and 4 °C. The crystallite heterogeneity, thermal stability, and ratio of inter- to intramolecular double helices were possibly the main driven factors for the observed digestion rates instead of the amount and micro-morphology of the crystallites. These results supply potential tools for the manufacture of food products with slower starch digestibility.
本研究考察了三种不同的储存温度，包括室温（RT）、4°C 和 -20°C，以研究它们对胶凝西米淀粉回生性质和体外消化率的影响。-20°C 储存导致形成的分子内和分子间双螺旋数量最高，并在扫描电子显微镜（SEM）下呈现出断裂样结构。这些晶区比 RT 和 4°C 储存条件下的晶区更均匀，但热稳定性更低。RT 储存显著增加了形成晶区的稳定性和异质性，导致 SEM 下呈现海绵状结构。因此，与 RT 和 4°C 储存相比，-20°C 储存后 α-淀粉酶对回生西米淀粉的消化速率显著降低。晶区的异质性、热稳定性以及分子间和分子内双螺旋的比例可能是影响观察到的消化速率的主要驱动因素，而不是晶区的数量和微观形态。这些结果为制造消化速度较慢的淀粉食品提供了潜在的工具。
