School of Biotechnology, Jiangnan University, Wuxi 214122, China.
J Sci Food Agric. 2010 Mar 15;90(4):658-63. doi: 10.1002/jsfa.3864.
The water absorption of wheat gluten plays an important role in the weight, volume and form ratio of the breads. In this paper, hydrothermal treatment and microbial transglutaminase (MTGase) modification were combined to improve the water absorption ratio (WAR) of wheat gluten. To understand the increases in WAR, the changes in MTGase reaction after gluten hydrothermal treatment were also investigated.
The sole hydrothermal treatment improved the WAR of gluten. The gluten treated at 100 degrees C for 30 min exhibited the highest WAR value (2.03 g g(-1) gluten) while the WAR of the control without hydrothermal treatment was 1.5 g g(-1) gluten. When gluten was exposed to 90 degrees C for 30 min followed by incubation with MTGase for 5 h, its WAR reached 2.48 g g(-1) gluten. In contrast to control gluten, the surface hydrophobicity of the gluten preheated at 90 degrees C for 30 min increased and fluctuated in a different way during the following MTGase reaction. Meantime, the trend in the amount of soluble protein of preheated gluten was also changed in the progress of MTGase reaction.
Hydrothermal treatment followed by MTGase reaction is an efficient approach to improve the WAR of wheat gluten. The analysis of catalytic process, including determination of ammonia, gluten surface hydrophobicity, soluble protein and SDS-PAGE, suggested that hydrothermal pretreatment accelerated the cross-linking reaction and may alter the ratio of gluten deamidation catalysed by MTGase, which induced an increase in the WAR.
小麦面筋的吸水性在面包的重量、体积和形状比中起着重要作用。在本文中，采用湿热处理和微生物转谷氨酰胺酶（MTGase）修饰相结合的方法来提高小麦面筋的吸水率（WAR）。为了了解 WAR 的增加，还研究了面筋湿热处理后 MTGase 反应的变化。
单独的湿热处理提高了面筋的 WAR。在 100°C 下处理 30 分钟的面筋表现出最高的 WAR 值（2.03gg(-1)面筋），而未经湿热处理的对照面筋的 WAR 值为 1.5gg(-1)面筋。当面筋在 90°C 下处理 30 分钟，然后用 MTGase 孵育 5 小时时，其 WAR 值达到 2.48gg(-1)面筋。与对照面筋相比，在 90°C 下预热 30 分钟的面筋的表面疏水性增加，并在随后的 MTGase 反应中以不同的方式波动。同时，预热面筋中可溶性蛋白的趋势也在 MTGase 反应过程中发生变化。
湿热处理后再进行 MTGase 反应是提高小麦面筋 WAR 的有效方法。通过对催化过程的分析，包括氨含量、面筋表面疏水性、可溶性蛋白和 SDS-PAGE 的测定，表明湿热预处理加速了交联反应，并可能改变 MTGase 催化的面筋去酰胺比例，从而导致 WAR 的增加。
