In vitro physiological functions such as jack bean (Canavalia ensiformis) urease inhibitory activity and retarding effect of glucose/bile acid of Aloe vera gel concentrated by the optimized DIS (Dewatering Impregnation & Soaking) process conditions were examined. Urease inhibitory activity of DIS aloes ranged from 84.6 to 94.4%, which was similar to or higher than 86.3% of fresh aloe. Also, urease inhibitory activity of DIS aloes was maintained at initial levels after heat treatment (90oC, 10 min.) and drying treatment (freeze or hot air drying). Urease inhibition pattern from Lineweaver-Burk plot indicated general non-competitive inhibition, and inhibition constants (KIE and KIES) of DIS aloes were 41-149 and 87-163 μL/mL, respectively. DIS(glucose) and DIS (polyethylene glycol) exhibited the highest retarding effect of glucose and bile acid. Their retarding effects were about 1.6 and 1.8 folds higher than that of fresh aloe after 0.5 and 1 hr of the dialysis, respectively. Conclusively, the above in vitro physiological functions of Aloe vera gel concentrated by DIS process suggested that aloe products treated with DIS would have the potential benefits for protection against Helicobacter pylori and reduction of blood glucose and cholesterol levels.

The structural and physicochemical properties of dried aloe vera gel by DIS (dewatering impregnation soaking) process under optimum conditions were investigated. FT-IR spectra for dried samples of DIS aloes showed the typical patterns of standard aloe polysaccharide, and surface structures by SEM (scanning electron microscopy) were similar to a gel-like structure. In case of physicochemical properties of dried aloe samples by DIS process, solubilities and swelling powers of control (not osmotic treated aloe), DIS (S) and DIS (G), samples treated by osmotic solution of 60% sucrose/0.25% NaCl and 50% glucose/0.5% NaCl, were 48.3-57.3% and 8.3-11.7%, respectively, showing no significant differences among samples, but swelling power of DIS (PEG), sample treated by using 50% polyethylene glycol as an osmotic agent was about 5 times higher that of control. Also, water holding capacities of control, DIS (S) and DIS (G) were similar to each other, but that of DIS (PEG) was about 5 times higher that of control. Oil holding capacities of control and DIS aloes maintained the 50.9-86.4% levels of water holding capacities showing no significant differences among samples. Rehydration ratio of DIS (PEG) aloes were significantly dependent on the temperature of rehydrated solvent (water), and rehydration ratio of not-fileted aloe was about two folds higher than that of fileted aloe.