Sustainable Production of Bioactive Pandan Leaf Extract Microcapsules via Optimized Ultrasound-Assisted Extraction and Spray Drying

Abstract

Pandan (Pandanus amaryllifolius Roxb.) leaves are a promising source of bioactive compounds, yet their application in functional foods remains limited due to the lack of optimized extraction and stabilization techniques. This study employed response surface methodology (RSM) to optimize ultrasound-assisted extraction (UAE) of pandan leaf extract (PLE), targeting maximal recovery of total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity (DPPH and FRAP assays). Optimal UAE conditions-60% ethanol, 40% amplitude, and 20-minute sonication-yielded extracts with significant antioxidant and antibacterial activities, with inhibition zones of 27 mm (Bacillus cereus), 29 mm (Staphylococcus aureus), and 18 mm (Escherichia coli). To enhance stability and facilitate incorporation into functional foods, the PLE was microencapsulated via spray drying using gum Arabic (GA), resistant maltodextrin (RMD), and their mixture (GRMD) in 1:1 and 1:2 ratios. The GRMD (1:1) formulation exhibited superior encapsulation efficiency (93.03%), bioactive retention, low water activity, and high solubility. Over 90 days of storage, microcapsules packed in vacuum-sealed aluminum foil laminated bags retained the highest bioactivity, with final TPC, TFC, DPPH, and FRAP values of 157.91 mg GAE/100g db, 21.49 mg QE/100g db, 324.75 mM Trolox/100g db, and 444.84 mM Trolox/100g db, respectively (p ≤ 0.05). This study demonstrates the potential of combining UAE and GRMD microencapsulation to sustainably produce stable, bioactive pandan leaf extract microcapsules for use in functional food systems. Further studies are recommended to assess sensory acceptance, bioaccessibility, and scale-up potential.