Spray Drying of Aonla Juice Mixed With Giloy Extract for Process Optimization, Product Development and Characterization

The combination of Giloy (Tinospora cordifolia) and Aonla (Phyllanthus emblica L.) offers significant health benefits, but the high perishability of their juices limits stability and bioactive compound retention. Spray drying presents a promising solution to enhance shelf life while preserving key nutrients. This study optimized the spray drying process for Aonla–Giloy juice using response surface methodology (RSM), evaluating powder recovery, moisture content, ascorbic acid, total phenolic content, color change, hygroscopicity, dispersibility, water solubility index, and overall acceptability. The effects of feed flow rate (2.1–4.1 mL/min), inlet air temperature (150°C–190°C), Aonla juice percentage (30%–70%), and maltodextrin concentration (20%–30%) were investigated. Among these, maltodextrin concentration had the most significant impact, followed by inlet air temperature, Aonla juice percentage, and feed flow rate. The optimized conditions (2.7 mL/min feed flow, 167°C inlet air temperature, 70% Aonla juice, 21.5% maltodextrin) resulted in high powder recovery (20.31%), ascorbic acid (675.93 mg/100 g), phenolic content (23,397.43 mg GAE/100 g), dispersibility (89.23%), solubility index (90.24%), and overall acceptability (86.37%), while maintaining low moisture content (6.34%), hygroscopicity (38.26%), and minimal color change (ΔE = 15.99). This study demonstrates the practical potential of spray drying for developing shelf-stable, bioactive-rich powders from medicinal plant-based juices, offering applications in the functional food and nutraceutical industries.