Institute of Agrophysics, Polish Academy of Sciences, Doświadczalna 4, 20-290 Lublin, Poland.
Molecules. 2019 Apr 25;24(8):1635. doi: 10.3390/molecules24081635.
The cross-linking and gelation of low-methoxy pectins are basic processes commonly used in different industries. The aim of this research was to evaluate the cross-linking process of the sodium carbonate-soluble pectins (named DASP) extracted from apples, characterized by a low degree of methylesterification as a function of its concentration in water (C). The cross-linking process was studied with a dynamic light scattering method, atomic force microscope (AFM), viscosity and pH measurements. An increase in C above 0.01% resulted in a decrease in the aggregation index (AI) and the change of its sign from positive to negative. The value of AI = 0 occurred at C = 0.33 ± 0.04% and indicated the formation of a pectin network. An increase in C caused the changes in viscosity of pectin solutions and the nanostructure of pectins spin-coated on mica observed with AFM, which confirmed results obtained. The hydrogen bonds were involved in the cross-linking process.
低甲氧基果胶的交联和胶凝是不同行业中常用的基本过程。本研究的目的是评估从苹果中提取的碳酸钠可溶果胶（命名为 DASP）的交联过程，其特点是甲酯化程度低，作为其在水中浓度（C）的函数。交联过程采用动态光散射法、原子力显微镜（AFM）、粘度和 pH 值测量进行研究。C 高于 0.01%时，聚集指数（AI）降低，其符号由正变为负。AI = 0 出现在 C = 0.33 ± 0.04%，表明形成了果胶网络。C 的增加导致果胶溶液的粘度变化以及 AFM 观察到的涂在云母上的果胶的纳米结构发生变化，这证实了所得到的结果。氢键参与了交联过程。
