College of Food Science, Southwest University, 2 Tiansheng Road, Beibei, Chongqing 400715, PR China; Laboratory of Quality & Safety Risk Assessment for Agro-products on Storage and Preservation (Chongqing), Ministry of Agriculture, Chongqing 400715, PR China.
Department of medical technology, Chongqing three gorges medical college, 366 Tianxing Road, Wanzhou, Chongqing 404120, PR China.
Int J Biol Macromol. 2018 Jun;112:951-960. doi: 10.1016/j.ijbiomac.2018.01.197. Epub 2018 Feb 6.
Chimonobambusa quadrangularis polysaccharides (CPS) were extracted by ultrasonic-assisted extraction from bamboo shoots (C. quadrangularis) processing by-products. Three polysaccharide fractions, CPS70, CPS75 and CPS80, were obtained by precipitation at final ethanol concentrations of 70%, 75% and 80%, respectively. The physicochemical characterization and chemical antioxidant activities of the three polysaccharide fractions were compared on the basis of HPLC, FT-IR, XRD, TGA, and antioxidant measurements in vitro. The results suggested that ethanol concentrations used for precipitation of CPS can affect its physicochemical and associated functional properties, and antioxidant activities. Compared with CPS70 and CPS80, CPS75 had lower glucose content, higher total sugar content, and higher protein and uronic acid contents. The CPS70 and CPS80 were composed of Man, Rha, GlcA, Glc, Gal, Xyl and Ara, but none of them were found to contain GalA. In contrast, CPS75 consisted of Man, Rha, GlcA, GalA, Glc, Gal, Xyl and Ara. CPS75 had the lowest medium-high-molecular-weight value (116.53-118.18kDa) and the highest medium-low-molecular-weight value (21.30-22.68kDa). Meanwhile, CPS75 exhibited better functional properties including the repose angle, swelling capacity (SC), water retention capacity (WRC), and oil retention capacity (ORC). Moreover, CPS75 possessed higher scavenging capacities on DPPH, hydroxyl and ABTS radicals, higher oxygen radical absorbance capacity (OARC), higher metal chelating activity, and more significant reducing power. According to the results above, a final ethanol concentration of 75% could be chose to precipitate polysaccharides from bamboo shoots (C. quadrangularis) processing by-products. In summary, it is strongly recommended that the ethanol concentration employed in precipitation of natural polysaccharides could be optimized in advance.
从竹笋（C. quadrangularis）加工副产物中，通过超声辅助提取，得到了慈竹多糖（CPS）。通过在最终乙醇浓度为 70%、75%和 80%时沉淀，得到了三个多糖级分，分别为 CPS70、CPS75 和 CPS80。基于 HPLC、FT-IR、XRD、TGA 和体外抗氧化测量，对这三个多糖级分的理化特性和化学抗氧化活性进行了比较。结果表明，用于沉淀 CPS 的乙醇浓度会影响其理化性质和相关功能特性以及抗氧化活性。与 CPS70 和 CPS80 相比，CPS75 的葡萄糖含量较低，总糖含量较高，蛋白质和糖醛酸含量较高。CPS70 和 CPS80 由 Man、Rha、GlcA、Glc、Gal、Xyl 和 Ara 组成，但均未发现 GalA。相比之下，CPS75 由 Man、Rha、GlcA、GalA、Glc、Gal、Xyl 和 Ara 组成。CPS75 的中高分子量值最低（116.53-118.18 kDa），中低分子量值最高（21.30-22.68 kDa）。同时，CPS75 表现出更好的功能特性，包括休止角、溶胀能力（SC）、持水能力（WRC）和持油能力（ORC）。此外，CPS75 对 DPPH、羟基和 ABTS 自由基的清除能力较高，氧自由基吸收能力（OARC）较高，金属螯合活性较高，还原能力较强。根据上述结果，最终可选择 75%的乙醇浓度来沉淀竹笋（C. quadrangularis）加工副产物中的多糖。总之，强烈建议在沉淀天然多糖之前，预先优化乙醇浓度。
