Department of Food and Nutrition, and Bionanocomposite Research Center, Kyung Hee University, Seoul 02447, Republic of Korea.
Department of Food and Nutrition, and Bionanocomposite Research Center, Kyung Hee University, Seoul 02447, Republic of Korea.
Int J Biol Macromol. 2024 Apr;265(Pt 1):130748. doi: 10.1016/j.ijbiomac.2024.130748. Epub 2024 Mar 11.
The present study aimed to investigate the structural and physicochemical characteristics of acid-extracted pumpkin pectic polysaccharide (AcPP) and to evaluate their flow rheological properties. AcPP was extracted from pumpkin pulp using the citric acid extraction method. The physicochemical and structural properties were analyzed by chemical methods and instrumental analyses. The obtained results showed that AcPP consisted predominantly of GalA (85.99 %) and small amounts of Rha, Gal, and Ara, with the ratio of HG/RG-I being 81.39/16.75. In addition, AcPP had medium DE (45.34 %) and contained four macromolecular populations with different Mw of 106.03 (main), 10.15, 4.99, and 2.90 kDa. The NMR analysis further confirmed that AcPP contained a linear backbone consisting of α-1,4-linked GalA residues, some of which were partially methyl-esterified. Furthermore, AcPP was amorphous in nature and had favorable thermal stability. The effects of extrinsic factors on the flow rheological properties of AcPP were evaluated. In particular, the high concentrations of CaCl (8 mM) and MgCl (10 mM) were effective in enhancing the viscosity and non-Newtonian shear-thinning behavior of the AcPP solution. This study elucidates the unique molecular structure of AcPP and suggests the potential of AcPP as a rheology modifier in low-viscous and mineral-reinforced beverages.
本研究旨在探究酸提南瓜果胶多糖（AcPP）的结构和物理化学特性，并评估其流动流变性能。采用柠檬酸提取法从南瓜果肉中提取 AcPP。通过化学方法和仪器分析对其理化和结构性质进行分析。结果表明，AcPP 主要由半乳糖醛酸（GalA）组成（85.99%），并含有少量鼠李糖、半乳糖和阿拉伯糖，HG/RG-I 比例为 81.39/16.75。此外，AcPP 的 DE 值适中（45.34%），包含四个不同 Mw 的高分子量群体，分别为 106.03（主要）、10.15、4.99 和 2.90 kDa。NMR 分析进一步证实 AcPP 含有由α-1,4 连接的 GalA 残基组成的线性主链，其中一些残基部分甲酯化。此外，AcPP 为无定形物质，具有良好的热稳定性。评估了外在因素对 AcPP 流动流变性能的影响。特别是，高浓度的 CaCl（8 mM）和 MgCl（10 mM）可有效提高 AcPP 溶液的黏度和非牛顿剪切变稀行为。本研究阐明了 AcPP 的独特分子结构，并表明 AcPP 作为低黏度和矿物质增强型饮料的流变改性剂具有潜力。
