Sage biomass powders by supercritical fluid extraction and hydro-distillation techniques: a comparative study of biological and chemical properties

Sage is a widely used herbal ingredient rich in bioactive compounds suitable for various applications. This study compared encapsulated Salvia officinalis L. powders derived from extracts obtained by supercritical fluid extraction (SESP) and hydro-distillation (HESP) for their characterisation and antioxidant activities. The SESP powder showed bulky agglomerated bio-feature from the morphology study, whereas the HESP powder showed more in individually separated round shape particles. The chemical functional groups’ analysis also revealed the presence of molecular interface between bio-components in both samples. Thermo-molecular analysis also revealed the SESP sample had more stable thermal changing behaviour than the HESP sample with increasing temperature. The total phenolic content (TPC) and Ferric Reducing Antioxidant Power (FRAP) value of HESP were significantly higher than that of SESP, at 29.419 ± 0.662 mgGAE/g ESP and 2011.494 ± 19.909 μM TE/g ESP, respectively. Additionally, high antioxidant activity was recorded in HESP based on its significantly low EC50 value as estimated in the DPPH assay, at 0.317 ± 0.002 mg/mL. Nonetheless, the performance of antioxidant activities for SESP was superior to that of unencapsulated sage extract obtained from similar extraction processes as reported in the literature. Thus, the results imply that SESP has a promising future as a natural alternative substituent for synthetic antioxidants in food, pharmaceutical, and biomedical applications.