School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
Carbohydr Polym. 2013 Feb 15;92(2):1249-55. doi: 10.1016/j.carbpol.2012.10.053. Epub 2012 Oct 29.
Although it is well known that structural variations occur in starch during gelatinisation, little is known about how the structure of starch changes at subgelatinisation levels. The objective of this study was to investigate structural variations of rice starch ascribed to the temperature during microwave heating. Rapid conduction heating was used to imitate the high microwave heating rate through oil bath, which was then compared with traditional conduction heating. Structural changes due to temperature increases were investigated using thermogravimetry and differential scanning calorimetry while the distinct lamellar organisation of starch was obtained through small-angle X-ray scattering. The results showed that the structure of starch responds non-monotonically to temperature rising before gelatinisation, which was also affected by heating rates. The samples treated by microwave and rapid conduction heating essentially underwent the same thermal property changes and the molecular vibration of the microwaves did influence the submicroscopic lamellar structure.
虽然人们深知在淀粉糊化过程中会发生结构变化，但对于淀粉在糊化以下阶段的结构变化知之甚少。本研究旨在探讨归因于微波加热温度的大米淀粉结构变化。通过油浴快速传导加热来模拟高微波加热速率，然后将其与传统传导加热进行比较。使用热重分析和差示扫描量热法研究由于温度升高而引起的结构变化，同时通过小角 X 射线散射获得淀粉的明显层状组织。结果表明，在糊化之前，淀粉结构对升温的响应是非单调的，升温速率也会对此产生影响。经微波和快速传导加热处理的样品基本经历了相同的热物性变化，微波的分子振动确实会影响亚微观层状结构。
