Lavender and hyssop productivity, oil content, and bioactivity as a function of harvest time and drying

Abstract

Field and laboratory experiments were conducted to evaluate the productivity and essential oil composition of lavender (Lavandula angustifolia Mill.) and hyssop (Hyssopus officinalis L.) as functions of year, harvest time, and drying. Lavender essential oil content ranged from 0.71 to 1.3% (overall average of 0.89%) and hyssop oil content ranged from 0.13 to 0.26% (overall average of 0.19%). Lavender and hyssop essential oil yields increased with time. Hyssop oil yields varied from 7.3kgha−1 to 19.6kgha−1, and lavender oil yields varied from 7.8kgha−1 to 55.5kgha−1. The major constituents of lavender oil were linalool (23.3–43.4%) and linalylacetate (20.2–39.6%), while the major constituents of hyssop oil were pinocamphene+isopinocamphene (57–75%) and β-pinene (5–15%). Lavender oil extracted from dry material had higher concentrations of linalyl acetate and caryophyllene but lower concentrations of myrcene than the oil from the fresh material. Delayed harvest of hyssop increased the concentrations of β-pinene, myrcene, and limonene+cineole but reduced pinocamphone+isopinocamphone. The chemical composition of the lavender and hyssop oil produced in Mississippi was similar to commercial oils from Bulgaria, Canada, France, and US. Lavender and hyssop can be established as essential oil crops in areas of the southeastern United States. Lavender and hyssop essential oils did not show significant antimicrobial, antileishmanial, antimalarial activity, and did not alter ruminal fermentation. However, commercial oil from L. latifolia reduced methane production in an in vitro digestibility study. The antioxidant activity of hyssop essential oil was 2039μmol of TE L−1, whereas the antioxidant activity of lavender essential oil was 328μmol of TE L−1.