Wageningen University & Research, Plant Breeding, P.O. Box 386, 6700 AJ Wageningen, the Netherlands; Aeres University of Applied Sciences, Department of Applied Research, P.O. Box 374, 8250 AJ Dronten, the Netherlands.
Wageningen University & Research, Plant Breeding, P.O. Box 386, 6700 AJ Wageningen, the Netherlands.
Carbohydr Polym. 2020 Jan 1;227:115353. doi: 10.1016/j.carbpol.2019.115353. Epub 2019 Sep 23.
Potato cell walls (PCW) are a low value by-product from the potato starch industry. Valorisation of PCW is hindered by its high water-binding capacity (WBC). The composition of polysaccharides and interactions between these entities, play important roles in regulating the WBC in the cell wall matrix. Here, we show that in vivo exo-truncation of RG-I β-(1→4)-D-galactan side-chains decreased the WBC by 6-9%. In contrast, exo-truncation of these side-chains increased the WBC by 13% in vitro. We propose that degradation of RG-I galactan side-chains altered the WBC of PCW, due to cell wall remodelling and loosening that affected the porosity. Our findings reinforce the view that RG-I galactan side-chains play a role in modulating WBC, presumably by affecting polysaccharide architecture (spacing) and interactions in the matrix. Better understanding of structure-function relationships of pectin macromolecules is needed before cell wall by-products may be tailored to render added-value in food and biobased products.
马铃薯细胞壁（PCW）是马铃薯淀粉工业的一种低附加值副产物。PCW 的增值受到其高结合水能力（WBC）的阻碍。多糖的组成和这些实体之间的相互作用在调节细胞壁基质中的 WBC 方面起着重要作用。在这里，我们表明，体内 RG-I β-（1→4）-D-半乳糖醛酸侧链的外切截断使 WBC 降低了 6-9%。相比之下，这些侧链的外切截断使体外的 WBC 增加了 13%。我们提出，由于细胞壁重塑和疏松影响了孔隙率，RG-I 半乳糖醛酸侧链的降解改变了 PCW 的 WBC。我们的发现证实了 RG-I 半乳糖醛酸侧链在调节 WBC 方面发挥作用的观点，这可能是通过影响基质中的多糖结构（间距）和相互作用。在细胞壁副产品可能被定制以在食品和生物基产品中赋予附加值之前，需要更好地了解果胶大分子的结构-功能关系。
