Abstract
ABSTRACT
This study investigated the effects of ultrasound‐assisted extraction (UAE), ethanol concentration (0%, 20%, 50%, 80%, and 99.5%), temperature (30°C, 50°C, and 70°C), and time on turmeric extraction by analyzing total soluble matter (TSM), antioxidant activity, and metabolomic profiles using ultra‐performance liquid chromatography (UPLC)‐QTOF‐MS and multivariate analysis. TSM generally increased with temperature and ethanol concentration, reaching its highest value at 50% ethanol and 70°C (20.44 g/100 g); under these conditions, TSM plateaued by 60 min and remained stable up to 200 min. Four‐way analysis of variance (ANOVA) confirmed significant condition‐dependent effects on TSM, whereas the UAE–CE (conventional extraction) differences in antioxidant activity were primarily associated with ethanol concentration (
p
< 0.001). UAE generally produced higher TSM and antioxidant activities than CE, with the greatest improvement observed at 30°C and intermediate ethanol concentrations (50%–80%). Representative scanning electron microscopy and quantitative image analysis demonstrated that extensive structural disruption with 99.5% ethanol caused severe surface opening but did not achieve the highest TSM, whereas UAE with 80% ethanol induced moderate tissue permeabilization and more complex boundary morphology, yielding superior extraction performance. Heatmap and principal component analysis (PCA) analyses revealed solvent‐ and method‐dependent variation in metabolite profiles. Qualitatively, UAE at 30°C recovered a comprehensive curcuminoid and lipid profile comparable to CE at the same temperature. Following rigorous false discovery rate (FDR) correction, statistically significant differences were restricted to a limited compound subset, demonstrating that UAE maintains overall metabolic integrity under mild thermal conditions. Ultimately, these findings support the potential of low‐temperature UAE parameters for efficient recovery of functional turmeric bioactives.