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Abstract：
The functional properties of food gums are remarkably affected by the quality of solvent/cosolutes and temperature in a food system. In this work, for the first time, the chemical characterizations and dilute solution properties of Lepidium perfoliatum seed gum (LPSG), as an emerging carbohydrate polymer, were investigated. It was found that xylose (14.27%), galacturonic acid (10.70%), arabinose (9.07%) and galactose (8.80%) were the main monosaccharaide components in the LPSG samples. The uronic acid content of LPSG samples was obtained to be 14.83%. The average molecular weight and polydispersity index of LPSG were to be 2.34 × 105 g/mol and 3.3, respectively. As the temperature was increased and the pH was decreased and the concentration of cosolutes (Na+, Ca2+, sucrose and lactose) presented in the LPSG solutions was enhanced, the intrinsic viscosity [η] and coil dimension (R coil , V coil , υ s ) of LPSG molecular chains decreased. Activation energy and chain flexibility of LPSG were estimated to be 0.46 × 107 J/kg.mol and 553.08 K, respectively. The relative stiffness parameter (B) of LPSG in the presence of Ca2+ (0.079) was more than that of Na+ (0.032). Incorporation of LPSG into deionized water (0.2%, w/v) diminished the surface activity from 76.75 mN/m to 75.70 mN/m. Zeta potential (ζ) values (-46.85 mV--19.63 mV) demonstrated that dilute solutions of LPSG had strong anionic nature in the pH range of 3-11. The molecular conformation of LPSG was random coil in all the selected solution conditions. It can be concluded that temperature and presence of cosolutes can significantly influence on the LPSG properties in the dilute systems.
摘要：
食品胶的功能特性受溶剂/共溶质的质量和食品体系中的温度的显著影响。在这项工作中,第一次,植物种子胶（LPSG）的化学特性和稀溶液特性，作为一种新兴的碳水化合物聚合物，被调查了。发现木糖（14.27%），半乳糖醛酸（10.70%），阿拉伯糖（9.07％）和半乳糖（8.80％）是LPSG样品中的主要单糖成分。LPSG样品的糖醛酸含量为14.83%。LPSG的平均分子量和多分散指数分别为2.34×105g/mol和3.3。随着温度的升高和pH的降低以及共溶质的浓度（Na+，Ca2+,LPSG溶液中存在的蔗糖和乳糖）得到了增强，特性粘度[η]和线圈尺寸(R线圈，V线圈,LPSG分子链的üs）降低。LPSG的活化能和链柔性估计为0.46×107J/kg。mol和553.08K，分别。在Ca2（0.079）存在下，LPSG的相对刚度参数（B）大于Na（0.032）。将LPSG掺入去离子水(0.2%，w/v）将表面活性从76.75mN/m降低到75.70mN/m。Zeta电位（ζ）值（-46.85mV-19.63mV）表明LPSG的稀溶液在3-11的pH范围内具有强阴离子性质。在所有选择的溶液条件下，LPSG的分子构象是无规卷曲的。可以得出结论，温度和共溶质的存在可以显着影响稀释系统中的LPSG特性。
