Akademik Veri Yönetim Sistemi
LWT, cilt.229, 2025 (SCI-Expanded, Scopus)
Pectin is widely used in the food industry as a thickener, stabilizer, emulsifier, filler and gelling agent. The macroscopic properties of pectin and pectin including food products are largely determined by the molecular motion and interactions of pectin with water molecules. 1H spin-lattice relaxation studies were carried out on water-pectin mixtures over a frequency range from 10 kHz to 10 MHz. The pectin powders used in this study were obtained from beet using different precipitation methods. Applying NMR relaxometry, the mechanisms of translational diffusion of water molecules have been revealed. The translational diffusion coefficient was found to be five orders of magnitude lower compared to that of bulk water, while the residence time of the water molecules bound to the pectin was determined to be of the order of microseconds. The dynamics is (almost) independent of temperature (in the range from 298K to 318K). The fraction of bound water molecules depends on the precipitation method. NMR relaxometry uniquely reveals how industrial precipitation methods tune pectin's hydration dynamics, offering strategies to design functional biopolymers for food applications. The corresponding relaxation contribution follows a power-law frequency dependence, but the power-law factor (varying between 0.15 and 0.19) is lower than factors predicted for polymer motion.