Enhancing the Physicochemical, Thermal, and Technological Properties of Freeze-Dried Welsh Onion Leaf Juice: Influence of Maltodextrin and Gum Arabic as Carrier Agents

Fresh Welsh onions are widely used in food formulations due to their distinctive flavor and biological properties, but their high perishability limits their industrial applications. In this study, powdered Welsh onion leaf juices were obtained through freeze-drying, with and without maltodextrin (MD) and gum arabic (GA) as carrier agents. MD was chosen for its high solubility and neutral taste, while GA was selected for its ability to improve powder stability and dispersibility. Powders were obtained using a completely randomized design to evaluate the effects of five MD:GA ratios (0:100, 25:75, 50:50, 75:25, and 100:0) on their physicochemical and technological properties. The addition of carriers enabled the formation of fine, homogeneous powders with higher water solubility. All formulations exhibited low water activity (<0.4) and moisture content (<7%). Polyphenol content ranged from 2.60 to 3.53 mg GAE/g of dry matter, with a high recovery percentage (94-96%). DPPH^• scavenging activity was about 0.55 mg GAE/g of dry matter for all powders with carrier agents. Fourier-transform infrared (FTIR) analysis confirmed the presence of characteristic bands from both the carrier agents and the onion leaf juice, while thermogravimetric analysis (TGA) revealed enhanced thermal stability with carrier agents. Flowability tests showed that MD and MD:GA blends significantly improved powder handling.