Lin Ximeng, Liu Keshan, Yin Sheng, Qin Yimin, Shen Peili, Peng Qiang
College of Food Science and Engineering, Northwest A&F University, Yangling 712100, China.
Beijing Engineering and Technology Research Center of Food Additives, Beijing Technology & Business University (BTBU), Beijing 100048, China.
Antioxidants (Basel). 2020 Feb 2;9(2):127. doi: 10.3390/antiox9020127.
After extraction from jujube pomace and purification by two columns (DEAE-Sepharose Fast Flow and Sepharcyl S-300), the structure of SAZMP4 was investigated by HPGPC, GC, FI-IR, GC-MS, NMR, SEM, and AFM. Analysis determined that SAZMP4 (Mw = 28.94 kDa) was a pectic polysaccharide mainly containing 1,4-linked GalA (93.48%) with side chains of 1,2,4-linked Rha and 1,3,5-linked Ara and terminals of 1-linked Rha and 1-linked Ara, which might be the homogalacturonan (HG) type with side chains of the RG-I type, corresponding to the results of NMR. In AFM and SEM images, self-assembly and aggregation of SAZMP4 were respectively observed indicating its structural features. The antioxidant activity of SAZMP4 against HO-induced oxidative stress in Caco-2 cells was determined by activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) as well as malondialdehyde (MDA) and reactive oxygen species (ROS) levels, indicating SAZMP4 can be a natural antioxidant. Also, a better water retention capacity and thermal stability of SAZMP4 was observed based on DSC analysis, which could be applied in food industry as an additive.
从枣渣中提取并经DEAE-琼脂糖快速流动柱和Sepharcyl S-300柱纯化后，通过高效凝胶渗透色谱法（HPGPC）、气相色谱法（GC）、傅里叶变换红外光谱法（FI-IR）、气相色谱-质谱联用法（GC-MS）、核磁共振法（NMR）、扫描电子显微镜法（SEM）和原子力显微镜法（AFM）对SAZMP4的结构进行了研究。分析确定SAZMP4（分子量 = 28.94 kDa）是一种果胶多糖，主要含有1,4-连接的半乳糖醛酸（93.48%），带有1,2,4-连接的鼠李糖和1,3,5-连接的阿拉伯糖侧链以及1-连接的鼠李糖和1-连接的阿拉伯糖末端，这可能是具有RG-I型侧链的同型半乳糖醛酸（HG）类型，与NMR结果相符。在AFM和SEM图像中，分别观察到了SAZMP4的自组装和聚集，表明了其结构特征。通过超氧化物歧化酶（SOD）和谷胱甘肽过氧化物酶（GSH-Px）的活性以及丙二醛（MDA）和活性氧（ROS）水平，测定了SAZMP4对Caco-2细胞中HO诱导的氧化应激的抗氧化活性，表明SAZMP4可以作为一种天然抗氧化剂。此外，基于差示扫描量热法（DSC）分析，观察到SAZMP4具有更好的保水能力和热稳定性，可作为添加剂应用于食品工业。
