State Key laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu Province, China.
State Key laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu Province, China.
Carbohydr Polym. 2016 Feb 10;137:147-153. doi: 10.1016/j.carbpol.2015.10.063. Epub 2015 Oct 17.
The impact of freezing on the wheat starches with different particle size was studied using a range of characterization methods including X-ray diffraction, differential scanning calorimetry, the Rapid Visco Analyser and a reconstitution dough system. Wheat starches were fractionated into A- and B-type granules, and then subjected to freezing/thawing treatment for 3 cycles. The freezing treatment did not cause apparent damage on A-type granular surface but induced cracked structure on B-type granules. It facilitated materials such as amylose, proteins, and lipids leaching from starch granule and an increase in gelatinization temperatures, melting enthalpy, and pasting viscosities. A smaller bread specific volume was obtained from freezing-treated B-granules while the crumb firmness significantly increased (p>0.05). No marked differences were observed in the counterparts of A-granules after freezing treatment. It seemed that the B-type granules were more sensitive to the freezing/thawing treatment, thus facilitating structural transformations from dough to bread. Results indicated that the deterioration in frozen bread quality derived from starch could be minimized by increasing the A-granules content.
采用 X 射线衍射、差示扫描量热法、快速黏度分析仪和面团再形成系统等一系列特性分析方法，研究了不同粒径的小麦淀粉在冷冻过程中的变化。将小麦淀粉分为 A 型和 B 型颗粒，然后进行 3 次冻融循环处理。冷冻处理并未明显破坏 A 型颗粒表面，但使 B 型颗粒出现裂纹结构。这有助于直链淀粉、蛋白质和脂质等物质从淀粉颗粒中浸出，使糊化温度、熔融焓和糊化黏度升高。经冷冻处理的 B 型颗粒制成的面包体积较小，但面包心硬度显著增加（p>0.05）。而 A 型颗粒经冷冻处理后，没有观察到明显差异。似乎 B 型颗粒对冻融处理更为敏感，从而促进了面团到面包的结构转变。结果表明，通过增加 A 型颗粒的含量，可以最大限度地减少由淀粉引起的冷冻面包品质劣化。
