College of Food Science and Nutritional Engineering, China Agricultural University, No. 17, Tsinghua East Road, Haidian District, Beijing 100083, China; National Engineering Research Center for Fruits and Vegetables Processing, No. 17, Tsinghua East Road, Haidian District, Beijing 100083, China.
College of Life Science, Qingdao University, No. 308, Ningxia Road, Laoshan District, Qingdao, Shandong 266071, China.
Food Res Int. 2023 Jan;163:112157. doi: 10.1016/j.foodres.2022.112157. Epub 2022 Nov 19.
Natural polysaccharides were isolated and purified from Cucurbita moschata by hot water extraction and mild acid-base sequential extraction. Chemical and instrumental studies revealed that hot water-extracted and mild acid-extracted polysaccharides with molecular masses of 48 kDa and 85 kDa were both pectic polysaccharides with homogalacturonan (HG) and rhamnogalacturonan-I (RG-I) domains, while mild acid-extracted polysaccharide was more dominated by branched RG-I with higher contents of galactose (10.59 %) and arabinose (8.08 %). Furthermore, mild acid-extracted polysaccharide exhibited better thickening and emulsifying properties, likely due to its larger molecular mass and higher branching degree. Mild base-extracted polysaccharide with a molecular mass of 18 kDa was a glucan-like polysaccharide. It showed the strongest thermostability and gel behavior among these pumpkin polysaccharides, likely attributed to its unique network structure stabilized by substantial intra/intermolecular hydrogen bonds. This study aimed to establish the structure-property relationships between these structurally diverse pumpkin polysaccharides from different extraction methods and provided theoretical foundations for their targeted application in foods.
从南瓜中用水提和弱酸-弱碱分步提取的方法分离和纯化天然多糖。化学和仪器研究表明，分子量分别为 48 kDa 和 85 kDa 的热水提取和弱酸提取多糖均为果胶多糖，具有同型半乳糖醛酸（HG）和鼠李半乳糖醛酸-I（RG-I）结构域，而弱酸提取多糖则更多地以支链 RG-I 为主，半乳糖（10.59%）和阿拉伯糖（8.08%）含量更高。此外，弱酸提取多糖具有更好的增稠和乳化性能，这可能与其较大的分子量和较高的支化度有关。分子量为 18 kDa 的弱酸提取多糖是一种类似葡聚糖的多糖。在这些南瓜多糖中，它表现出最强的热稳定性和凝胶行为，这可能归因于其独特的网络结构，由大量的分子内/分子间氢键稳定。本研究旨在建立不同提取方法得到的这些结构多样的南瓜多糖的结构-性能关系，为其在食品中的靶向应用提供理论基础。
