Effects of spray-drying temperatures and carriers on physical and antioxidant properties of lemongrass leaf extract powder

Abstract

This research was conducted to identify influences of spray-drying temperatures and carriers on physical and antioxidant properties of lemongrass leaf extract powder. Two variables including: inlet temperatures (110◦ C, 120◦ C, 130◦ C, 140◦ C and 150◦ C) and carriers (Gum Arabic, Maltodextrin and Gum Arabic: Maltodextrin mixture) were studied. Loose density, moisture content, solubility, total phenolic content (TPC), total flavonoid content (TFC) and antioxidant capacity of the obtained powder were analyzed. Overall, moisture content, TPC and TFC were reduced; however, loose density, solubility and antioxidant capacity were enhanced when temperature increased. Among all powder samples, the one produced at 110◦ C had the highest TPC (3.02 mg GAE/100 g DW) and TFC (541.82 mg CE/100 g DW) compared to the others. However, due to high moisture content, which is not suitable for the shelf life of powder product, this condition cannot be recommended as a favorable condition for lemongrass powder manufacturing. The powder samples produced by mixing with Maltodextrin at 130◦ C retained the high levels of antioxidant capacity, TFC, TPC and had the highest water-soluble ability and lowest moisture content as compared to the others, matching well with quality requirements for an instant powder product.