Extraction of nutrients from plants is an important unit operation in the food and biological industries. The target nutrient is usually spatially distributed throughout the plant tissue. The intact cell wall and adhering membranes are the main resistances to molecular diffusion. Therefore, disintegration of the intact structure, which in turn increases the permeability of adhering membranes, can significantly improve the nutrient extraction yield and efficiency. In this study, different physical treatments (homogenization, high pressure homogenization, and ball mill grinding) were applied to investigate their effects on the tissue microstructure and the release of vitamin C. The changes in the microstructure were reflected by LF-NMR based on T₂ distribution, particle size distribution, and microscopy images. The extraction yield of vitamin C obtained by high-pressure homogenization was increased by 75.69% for floret and 28.84% for stalk, respectively, as compared to that obtained by mechanical homogenization. The degradation of vitamin C was significant due to prolonged operation of the ball mill grinding method although the integrity of the tissues was similar to that of the high-pressure homogenization-treated tissues. This study confirms that the degree of tissue disintegration has a positive correlation with the release of the nutrient (vitamin C) within a limited operating time. LF-NMR has been proven to be an effective method to study the impact of different physical treatments on the cellular structure integrity of plant-originated food materials.

中文翻译：

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用LF-NMR 研究机械处理对西兰花（Brassica oleracea L. var.italica） 细胞结构完整性和维生素C可提取性的影响。

从植物中提取营养素是食品和生物工业中的重要单元操作。目标养分通常在空间上分布在整个植物组织中。完整的细胞壁和粘附的膜是对分子扩散的主要阻力。因此，完整结构的分解进而增加了粘附膜的渗透性，可以显着提高养分的提取产量和效率。在这项研究中，采用了不同的物理处理方法（均质化，高压均质化和球磨机研磨）来研究其对组织微结构和维生素C释放的影响。基于T的LF-NMR反映了微结构的变化_2个分布，粒度分布和显微镜图像。与机械均质化相比，高压均质法提取的维生素C的提取率小花和茎分别提高了75.69％和28.84％。尽管组织的完整性类似于高压均质处理过的组织，但由于球磨机研磨方法的延长操作，维生素C的降解显着。这项研究证实，组织崩解的程度与在有限的操作时间内营养素（维生素C）的释放呈正相关。LF-NMR已被证明是研究不同物理处理对源自植物的食品原料的细胞结构完整性的影响的有效方法。