Abstract
Pectin from agricultural by-products created gel beads with and without activated carbon through freeze-drying and atmospheric drying. In this study, recovered pectin had an extra high molecular weight of 399,498 – 1881,678 kDa and a low methoxyl content of 3.3 %. Pectin: chitosan: activated carbon ratio = 2:2:1 was chosen to reach hard gel beads and original gel shape after drying. FTIR spectra between PCZn-AD and PCZn-FD, PCAZn-AD, and PCAZn-FD had no difference, proving that the drying method did not affect the surface functional groups of the obtained material. Scanning Electron Microscopy images showed that PCZn-AD and PCZn-FD particles were spherical with rough, scaly surfaces; about PCZn-AD, the surface was wrinkled and grouped while the PCZn-FD surface was rough, with many thin layers and more voids. Pectin is a macromolecular material with a specific surface area of 0.02 - 1.32 m2/g. The swelling degree of the freeze-drying gel beads was higher than the atmospheric drying gel beads. The stability of the gel beads was clearly demonstrated at pH < 7.
