Structural changes of lignin-carbohydrate complexes (LCCs) from Chinese quince fruits during the sequential fractionation of pectic and hemicellulosic polysaccharides

• Published in: International journal of biological macromolecules 2021-12, Vol.192, p.1256-1265
• Main Authors: Wei, Ya-Nan, Wang, Chu-Yong, Fu, Chao-Qiang, Liu, Hua-Min, Qin, Zhao, Wang, Xue-De
• Format: Article
• Language: English
• Subjects: Carbohydrates - chemistry; Chemical Fractionation; Chinese quince; Lignin - chemistry; Lignin-carbohydrate complexes; Macromolecular Substances - chemistry; Molecular Weight; Pectin and hemicellulose; Pectins - chemistry; Pectins - isolation & purification; Polysaccharides - chemistry; Polysaccharides - isolation & purification; Rosaceae - chemistry; Spectrum Analysis
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2021.10.085

Chinese quince (Chaenomeles sinensis) fruits offer a potential source of pectin and hemicellulose. However, the existence of lignin-carbohydrate complexes (LCCs) can negatively impact the extraction of pectin and hemicellulose. In this work, LCCs were sequentially fractionated from Chinese quince during the removal of pectin and hemicellulose. The structures of LCCs were characterized by HPAEC, FT-IR, GPC, Py-GC/MS, TGA and 2D HSQC NMR. The results showed that the carbohydrate content and molecular weight of LCCs was found to be changed significantly after the removal of hemicellulose (KSH). The lignin in Björkman LCCs was found to be linked mainly to galactan and fructan, whereas the lignin LCC-AcOHs was found to be linked mainly to arabinan after the removal of KSH. The isolation of carbonate-soluble pectin (NSP) increased thermal stability of Björkman LCC fraction, however, the isolation of chelator-soluble pectin (CSP) increased the thermal stability of LCC-AcOHs. The S/G ratios of LCC-AcOHs increased and large amounts of S-type lignin released during sequential fractionation of pectin and hemicellulose. These results will be beneficial for understanding the mechanisms of pectin and hemicellulose isolation, thereby facilitating the potential application of Chinese quince as a valuable natural resource for food and other industries. •The structural changes of LCCs during the sequential removal of pectin and hemicellulose were proposed.•Galactan-lignin and fructan-lignin complexes were the major composition in Björkman LCCs.•The S/G ratio of LCC-AcOH fractions increased as the sequential fractionation.•The removal of S-type lignin will effectively promote the extraction of pectin and hemicellulose.