LOSS OF CRYSTALLINE AND MOLECULAR ORDER DURING STARCH GELATINIZATION - ORIGIN OF THE ENTHALPIC TRANSITION
LOSS OF CRYSTALLINE AND MOLECULAR ORDER DURING STARCH GELATINIZATION - ORIGIN OF THE ENTHALPIC TRANSITION
复制标题
DOI：
10.1016/0008-6215(92)85063-6
复制
发表时间：
1992-04-06
影响因子：
3.1
通讯作者：
GIDLEY, MJ
中科院分区：
文献类型：
--
作者：
COOKE, D;GIDLEY, MJ
通过从玉米、糯玉米、小麦、马铃薯和木薯淀粉中分离干燥样品，经过确定的热预处理，研究了淀粉颗粒糊化过程中发生的分子秩序破坏。用c -13- c.p.a -m.a.s -n.m.r测定残余分子和结晶顺序。结果与dsc法测定的剩余糊化焓进行了比较。对于天然淀粉，分子（双螺旋）顺序明显大于晶体顺序。分子和晶体顺序都与热预处理后的糊化残余焓相关，这表明在糊化过程中，这两个层次的结构同时被破坏。根据获得的数据，计算了所研究的淀粉的完全有序和结晶类似物的预测焓值，并与基本上完全有序和结晶的模型材料的值进行了比较。这一比较表明，糊化焓主要反映了分子（双螺旋）秩序的损失。
The disruption of molecular orders which occur during the gelatinisation of starch granules has been studied by isolating dried samples from maize, waxy maize, wheat, potato, and tapioca starches after defined thermal pre-treatments. Residual molecular and crystalline order was quantified by C-13-c.p.-m.a.s.-n.m.r. spectroscopy and powder X-ray diffraction, respectively, and the results compared with residual gelatinisation enthalpy determined by d.s.c. For native starches, molecular (double-helical) order was significantly greater than crystalline order. Molecular and crystalline order were both found to correlate with the residual enthalpy of gelatinisation following thermal pre-treatment, indicating that both levels of structure are disrupted concurrently during gelatinisation. From the data obtained, predicted enthalpy values for the disruption of fully ordered and crystalline analogues of the starches studied were calculated, and compared with values for essentially fully ordered and crystalline model material. This comparison suggests that the enthalpy of gelatinisation primarily reflects the loss of molecular (double-helical) order.