Stabilization of Aloe Vera Gel By Interaction with Sulfated Polysaccharides from Red Microalgae and with Xanthan Gum

Aloe vera gel—the fiber-free mucous exudate of the succulent leaves of aloe vera (Aloe barbadensis Miller)—was mixed with sulfated polysaccharides isolated from the red microalgae Porphyridium sp., Porphyridium aerugineum, and Rhodella reticulata, with the natural anionic polysaccharide xanthan gum or with nonionic guar gum to determine possible stabilizing effects. Rheological studies indicated interaction between aloe vera gel and the algal polysaccharides and xanthan gum as shown by increased apparent viscosities, apparent yield points, and, in some cases, hysteresis but not with guar gum. These properties did not deteriorate during storage. It was therefore proposed that the algal polysaccharides or xanthan gum could serve to stabilize the network structure of fresh aloe vera polysaccharides.