Key Laboratory of Plant Resources Conservation and Sustainable Utilization, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Key Laboratory of Plant Resources Conservation and Sustainable Utilization, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.
Food Chem. 2019 Jul 30;287:346-353. doi: 10.1016/j.foodchem.2019.02.100. Epub 2019 Feb 28.
The degradation of cell wall polysaccharides is highly associated with the softening process of banana. In this work, banana was treated by morin to delay softening during storage. Water-soluble polysaccharides were extracted from banana pulp at four storage stages. Their levels increased when the banana was green, but decreased when turned to yellow. Three types of polysaccharides were identified by nuclear magnetic resonance spectroscopy, including starches, homogalacturonans and arabinogalactan proteins. (1 → 4)-α-D-galacturonan constructed the backbone of homogalacturonans, which was the leading water-soluble polysaccharide in the last stage. Starch was the dominant polysaccharide at all stages in morin-treated banana. Deassembly of insoluble starch granules and degradation of soluble starches were responsible for its high level in banana. Arabinogalactan proteins were only detected in late stages, and could be a marker for banana deterioration. The inhibited degradation of cell wall polysaccharides contributed to the preservative effect of morin.
细胞壁多糖的降解与香蕉的软化过程密切相关。在这项工作中，使用桑色素处理香蕉以延缓贮藏过程中的软化。在四个贮藏阶段从香蕉果肉中提取水溶性多糖。香蕉呈绿色时，其含量增加，但变成黄色时含量下降。通过核磁共振波谱鉴定出三种多糖，包括淀粉、同质半乳糖醛酸聚糖和阿拉伯半乳聚糖蛋白。（1→4）-α-D-半乳糖醛酸构建了同质半乳糖醛酸聚糖的骨架，是最后阶段主要的水溶性多糖。在桑色素处理的香蕉中，淀粉是所有阶段的主要多糖。不溶性淀粉颗粒的解体和可溶性淀粉的降解导致其在香蕉中的含量较高。阿拉伯半乳聚糖蛋白仅在后期检测到，可能是香蕉劣化的标志物。细胞壁多糖降解的抑制有助于桑色素的保鲜效果。
