2001-08-012024-05-18https://scholars.lib.ntu.edu.tw/handle/123456789/711235摘要：小麥或糯性米澱粉-雙醣-水系統在糊化與凍藏時之熱性質及水分子移動性質分別以調幅式示差熱掃描熱分析儀(MDSC)及核磁共振影像分析儀之氫原子核自旋-自旋弛緩時間(T2)之測定探討。結果顯示，添加雙醣會延緩澱粉糊化的時間，即提高澱粉糊化所需的溫度，其延緩的程度隨著醣濃度的提高而增加，延緩能力則為蔗糖＞海藻醣＞麥芽糖。當糊化的澱粉-雙醣膠體進行凍藏時，系統中的冰晶生成量隨著醣濃度的提高而減少，且冰晶溶解溫度隨著醣濃度的提高而降低。由核磁共振影像分析儀之氫原子核自旋-自旋弛緩時間(T2)之測定結果顯示，當澱粉膠中含有添加醣時，會降低系統中的T2值，且不同的雙醣會造成膠體中不同的T2值分布情形。添加雙醣應可避免澱粉膠體在凍藏時因系統中冰晶的產生而破壞了澱粉膠體的結構，此可由系統中測得的T2值下降得知系統中水的自由度因雙醣的親水性而下降所得到的結果。雖然在糯性米澱粉膠體中添加雙醣對其抗凍的效果不亦觀察到，但添加雙醣對非糯性組成之小麥澱粉膠體則有顯著的效果。<br> Abstract: The thermal properties of the starch- disaccharide-water system were studied by using Modulated Differential Scanning Calorimetry (MDSC) to investigate the properties of gelatinization and ice melting during frozen. The proton spin-spin relaxation time (T2) was determined by using Magnetic Resonance Imaging (MRI) to study the effect of three disaccharides (trehalose, sucrose and maltose) on the water mobility in wheat and waxy rice starch gel. The addition of disaccharide delay the starch gelatinization with the order of sucrose > trehalose > maltose, and the retardation increases with the increase of sugar concentration. The amount of ice formation and melting temperature of ice of starch gel significantly decrease and lower with increasing of sugar concentration, respectively. The MRI results show that the addition of sugar on starch gel decreases its T2 value and type of sugar affects its T2 distribution. Sugars would prevent starch gel from microstructural destruction under freezing because water mobility was lower and less water was available for the ice formation when sugar was added. Because waxy rice starch gel has a lower T2 and less ice formation than wheat starch gel, the cryopreservation of disaccharides is more obvious in wheat starch gel.糯性米澱粉小麥澱粉蔗糖海藻醣麥芽糖調幅式示差熱掃描熱分析氫原子核自旋-自旋弛緩時間waxy rice starchwheat starchtrehalosesucrosemaltosemodulated differential scanning calorimetryproton spin-spin relaxation time (T2)