Abstract Wheat (Triticum aestivum L) and barley (Hordeum vulgare L) are two important cereals cultivated worldwide. The effect of aleurone cell wall structure on water diffusion and distribution within wheat and barley grains was evaluated at different relative humidity levels. Time domain nuclear magnetic resonance was used to measure the transverse relaxation time T2 of grains. Two water states were distinguished within grains, namely W1 (lower mobility) and W2 (higher mobility). Grains with thicker aleurone layer cell walls had a higher W2. The water-absorption and desorption rates were mainly determined by the thickness of the aleurone cell walls and decreased with increasing cell wall thickness. The higher W2 values observed in grains with thicker aleurone cell walls with the a water content of 2.0% (w/w) and 12.1% (w/w) were probably related to a higher water motion within the grains, in response to higher porosity. Arabinoxylan and (1,3)(1,4)-β-glucan alternating multilayer films were prepared, each film had 20 layers, one layer was approximately 1 μm thick. The film was used as a model to simulate the aleurone layers. These results show that cell walls of the aleurone layer regulate the diffusion and distribution of water within grains.

中文翻译：

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糊粉细胞壁在谷物内水扩散和分布中的作用

摘要 小麦（Triticum aestivum L）和大麦（Hordeum vulgare L）是世界范围内种植的两种重要谷物。在不同的相对湿度水平下，评估了糊粉细胞壁结构对小麦和大麦籽粒内水分扩散和分布的影响。时域核磁共振用于测量晶粒的横向弛豫时间T2。晶粒内有两种水状态，即 W1（较低的迁移率）和 W2（较高的迁移率）。糊粉层细胞壁较厚的谷物具有较高的 W2。吸水和解吸速率主要由糊粉细胞壁的厚度决定，并随着细胞壁厚度的增加而降低。在含水量为 2.0% (w/w) 和 12 的糊粉细胞壁较厚的谷物中观察到较高的 W2 值。1% (w/w) 可能与颗粒内较高的水运动有关，以响应较高的孔隙度。制备阿拉伯木聚糖和(1,3)(1,4)-β-葡聚糖交替多层薄膜，每层薄膜20层，一层约1μm厚。该膜用作模型来模拟糊粉层。这些结果表明糊粉层的细胞壁调节水在谷物内的扩散和分布。