Abstract：
Pectin, a complex polysaccharide found in plant cell walls, plays a crucial role in various industries due to its functional properties. The diluted alkali-soluble pectin (DASP) fractions that result from the stepwise extraction of apples and carrots were studied to evaluate their structural and rheological properties. Homogalacturonan and rhamnogalacturonan I, in different proportions, were the main pectin domains that composed DASP from both materials. Atomic force microscopy revealed that the molecules of apple DASP were longer and more branched. A persistence length greater than 40 nm indicated that the pectin molecules deposited on mica behaved as stiff molecules. The weight-averaged molar mass was similar for both samples. Intrinsic viscosity values of 194.91 mL·g-1 and 186.79 mL·g-1 were obtained for apple and carrot DASP, respectively. Rheological measurements showed greater structural strength for apple-extracted pectin, whereas carrot pectin was characterized by a higher linear viscoelasticity limit. This comparison showed that the pectin fractions extracted by diluted alkali are structurally different and have different rheological properties depending on their botanical origin. The acquired insights can enhance the customized use of pectin residue and support further investigations in industries relying on pectin applications.
摘要：
果胶,一种在植物细胞壁中发现的复杂多糖，由于其功能特性，在各种行业中起着至关重要的作用。研究了逐步提取苹果和胡萝卜产生的稀释的碱溶性果胶（DASP）级分，以评估其结构和流变特性。同半乳糖醛酸和鼠李糖半乳糖醛酸I，以不同的比例，是两种材料组成DASP的主要果胶结构域。原子力显微镜显示，苹果DASP的分子更长，更分支。大于40nm的持续长度表明沉积在云母上的果胶分子表现为刚性分子。两种样品的重均摩尔质量相似。苹果和胡萝卜DASP的特性粘度值分别为194.91mL·g-1和186.79mL·g-1，分别。流变学测量显示，苹果提取的果胶具有更大的结构强度，而胡萝卜果胶的特征是具有较高的线性粘弹性极限。该比较表明，通过稀释碱提取的果胶级分在结构上不同，并且根据其植物来源具有不同的流变特性。获得的见解可以增强果胶残留物的定制使用，并支持依赖果胶应用的行业的进一步研究。
