为改善果糖因其强吸湿性而导致的结块和潮解现象，通过绘制吸湿曲线，吸湿等温线，宏观形态分析，接触角测定以及低场核磁等表征手段，考察谷朊粉（Wheat Gluten，WG）添加量对果糖冻干品吸湿特性的影响，并比较了谷朊粉中两种主要成分：麦醇溶蛋白和麦谷蛋白的作用差异。结果表明，谷朊粉显著降低了冻干果糖样品的平衡吸湿率（Equilibrium Moisture Content，EMC），在25 ℃、75%相对湿度下果糖与谷朊粉比例为10:0、3:7、2:8的EMC分别为36.33%、16.00%、14.61%；随着谷朊粉比例的增加，样品的结块程度减弱，接触角由11.3 °增大到94.8 °。Peleg模型可以准确描述果糖-蛋白体系的水分吸附过程；相较于麦醇溶蛋白，添加麦谷蛋白的样品EMC更低，结块量更小，且麦谷蛋白的接触角（88.2 °）大于麦醇溶蛋白（64.6 °）；低场核磁结果显示，与麦醇溶蛋白相比，麦谷蛋白对降低水分自由度产生了更有效的影响。以上结果表明，谷朊粉及其主要组分对果糖的吸湿有显著的抑制作用，相较于麦醇溶蛋白，麦谷蛋白抑湿效果更突出。

In order to improve the agglomeration and deliquescence of fructose owing to its strong hygroscopicity, the effect of adding wheat gluten (WG) on the hygroscopic properties of freeze-dried fructose were investigated using characterization methods, including hygroscopic curves and isotherms, macroscopic morphological analysis, determination of contact angles, and low-field NMR. Subsequently, the differences in the effects of the two main components of WG, gliadin and glutenin, were compared. The results showed that the addition of WG considerably reduced the equilibrium moisture content (EMC) of the freeze-dried fructose samples. Under conditions of 25 ℃ and 75% relative humidity, the EMCs were 36.33%, 16.00% and 14.61% when the respective mass ratios of fructose to WG were 10:0, 3:7, and 2:8. As the proportion of WG increased, the degree of agglomeration of the sample decreased, whilst the contact angle increased from 11.3 ° to 94.8 °. The Peleg model accurately described the water adsorption process of the fructose-protein system. The EMC of the sample with the addition of glutenin was lower, with a smaller amount of agglomeration compared to that of gliadin. Furthermore, the contact angle of glutenin (88.2 °) was greater than that of gliadin (64.6 °). Low-field NMR results showed that glutenin was more effective at reducing the degree of moisture freedom compared to gliadin. These results demonstrate that WG and its main components have a significant inhibitory effect on the hygroscopicity of fructose, and that glutenin is more effective compared to gliadin for the inhibition of moisture absorption.

国家自然科学基金项目（31871844）