Acoustic cavitation-mediated ultrasound-assisted extraction enhances recovery of antioxidant and antidiabetic phytochemicals from Tanacetum gracile: Stabilization through alginate–whey protein microencapsulation

Ultrasound-assisted extraction (UAE) offers a rapid process-intensification approach for recovering plant-derived bioactive compounds, while subsequent microencapsulation may improve their post-extraction stability. This study investigated the recovery and stabilization of antioxidant and antidiabetic phytochemicals from Tanacetum gracile using UAE followed by alginate–whey protein microencapsulation. Ultrasonic amplitude (40–80%) and extraction time (20–60 min) were evaluated under fixed extraction conditions of 100% ethanol, 1:10 solid-to-solvent ratio, 50–60 kHz frequency, and 30 ± 2 °C. The best-performing amplitude–time combination within the investigated experimental domain was identified based on extraction yield, total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity. The 80% amplitude–20 min treatment produced the highest TPC (138.98 mg GAE g −1 ), TFC (32.05 mg QE g −1 ), DPPH inhibition (74.87%), ABTS scavenging activity (97.56%), and FRAP (571.59 μmol TEAC g −1 ), whereas maximum crude extraction yield (28.30%) occurred at 80% amplitude–60 min. Estimated energy input increased from 240 to 1440 kJ across the experimental conditions; prolonged high-amplitude treatment increased extract yield only marginally while markedly reducing antioxidant responses. GC–MS profiling of the selected extract revealed diverse metabolites, including monoterpenes, phenolic derivatives, flavonoids, sesquiterpenes, and fatty acids. The optimized extract was subsequently encapsulated using sodium alginate, whey protein isolate, and their 50:50 combination. The alginate–whey protein matrix provided the highest retention of TPC (139.86 mg GAE g −1 ), TFC (32.35 mg QE g −1 ), DPPH activity (71.51%), and FRAP (570.48 μmol TEAC g −1 ), and exhibited the strongest in vitro α-amylase (79.56%) and α-glucosidase (83.45%) inhibition. Overall, the integrated UAE–microencapsulation strategy provides a laboratory-scale proof of concept for recovering and stabilizing T. gracile phytochemicals as potential functional-food ingredients. Further studies are required to establish food-matrix compatibility, gastrointestinal bioaccessibility, storage kinetics, safety, and scale-up feasibility.