Antioxidant activity of extracts obtained by different isolation procedures from some aromatic herbs grown in Lithuania

TLDR

An increasing demand for natural additives has shifted the attention from synthetic to natural antioxidants. The study evaluates Lithuanian aromatic herbs—marjoram, catnip, oregano, lavender, thyme, hyssop, anise hyssop, and sage—as potential natural antioxidant sources. Herb samples were extracted with supercritical CO₂, acetone, methanol/water, and hydrodistillation, and deodorised samples were also acetone‑extracted; antioxidant activity of extracts, essential oils, and aqueous extracts was measured by β‑carotene bleaching tests. Polar solvents yielded the highest extraction yields, and thyme and sage acetone oleoresins displayed the strongest antioxidant activity, making them the most promising sources. © 1998 SCI.

Abstract

An increasing demand for natural additives has shifted the attention from synthetic to natural antioxidants. The present work examines the potential of some aromatic herbs grown in Lithuania as a source of natural antioxidants: marjoram (Majorana hortensis Moench), catnip (Nebeta cataria L), oregano (Origanum vulgare L), lavender (Lavandula angustifolia Mill), thyme (Thymus vulgaris L), hyssop (Hyssopus officinalis L), anise hyssop (Lophantus anisatus Benth), and sage (Salvia officinalis L). Dried herb samples were submitted to extraction with supercritical CO2, acetone or methanol/water and hydrodistillation. Deodorised herb samples (after removal of essential oil) were also extracted with acetone. The antioxidant activity of these extracts, essential oils and dried deodorised aqueous extracts was assessed by the β-carotene bleaching test (diffusion and spectrophotometric methods). The highest yields of extracts were obtained using polar solvents. Thyme and sage acetone oleoresins showed high antioxidant activity in the tests performed and were regarded as the most promising sources. © 1998 SCI.