Chemical changes of aloe vera gel during the preparation of instant powder and its antioxidant activity

Aloe vera contains flavonoid compounds with high antioxidant activity in powder form, which is usually affected by the encapsulating agent. Maltodextrin is currently used as an encapsulating agent because of its high solubility, while gum arabic is a viscous substance that increases oxidation resistance. Therefore, this study aimed to produce aloe vera instant powder with a mixture of maltodextrin and gum arabic as an encapsulating agent and evaluate the chemical changes during the preparation of powder with high antioxidant activity. The powder was processed by mixing aloe vera gel with an encapsulating agent of maltodextrin and gum arabic mixture in a ratio of 1/1 with variations of 5%, 10% and 15%. Each sample was dried using a drum dryer at 120°C, 130°C and 140°C. During preparation, the samples were analyzed for their moisture content, phenolic content, flavonoid content and antioxidant activity expressed as DPPH radical scavenging activity. The results showed that the addition of encapsulating agents decreased the moisture content, phenolic content, and flavonoid content of aloe vera gel, however no significant effect (p>0.05) on antioxidant activity. Drying at a higher temperature will produce aloe vera powder with higher antioxidant activity. The aloe vera instant powder which was produced with a 5% encapsulating agent at the drying temperature of 130°C had high antioxidant activity of 26.21±7.58%.