Basil Ocimum L. belongs to the perspective aromatic and essential-oil plants. Its green mass and essential oils can be successfully used in different sectors of economy including food industry. In 56 samples of basil Ocimum L. having different ecological and geographic origin the author determined the content and yield of essential oils. The study of the taken basil cultivars shows that the content of essential oils in different types of basil (sweet basil – Ocimum basilicum L., holy basil – Ocimum tenuiflorum L., camphor basil – Ocimum kilimandscharicum Willd., hoary basil – Ocimum canum Sims.) was 0.28–0.83% when its yield was 24.0–314.6 kg/ha and green mass yield during technological maturity phase (massive flowering) was 0.51–5.08 kg/m2. By means of gas liquid chromatography method the author performed compositional and anantiometric analysis of the composition of the essential oils obtained from the new basil varieties such as Ocimum L. (Magiya, Volodar, Nastena, Istochnik), bred in Belorussian State Agricultural Academy and catalogued in the National Register of Cultivars in the Republic of Belarus. As a result of the research the author determined that essential oil samples obtained from the new basil cultivars have up to 20 components. The main components are linalool, methyl chavicol, - and -pinenes, -terpineol, eugenol, geraniol, geranial, geranyl acetate, thymol, neral, carvone, carvacrol, limonene and 1.8-cineol. Enantiomers are present in essential oil components - and -pinenes, limonene and linalool.

Spices, herbs, and essential-oil plants provide a lot of marketable products, e.g., green mash, seeds, essential oils, etc. These raw materials find application in food industry, pharmacy, perfumery, traditional and folk medicine, landscape gardening, etc. The research objective was to test some new varieties of spices, aromatic herbs, and essential oil crops for their yield and fatty acid composition. The study featured new varieties of medicinal hyssop (Hyssopus officinalis L.), oregano (Origanum vulgare L.), basil (Ocimum basilicum L.), tulsi (Ocimum tenuiflorum L.), garlic chives (Allium odorum L.), rue (Ruta graveolens L.), blue fenugreek (Trigonella caerulea (L.) Ser.), and big-root geranium (Geranium macrorrhizum L.). The yield of green mass and seeds was studied on the experimental field of the Belarusian State Agricultural Academy according to standard methods. A set of standard laboratory procedures made it possible to define the content of crude fat, while the fatty acid composition of seed lipids was studied by gas chromatography in extracts of methyl esters of fatty acids. The green mass yield was 150–280 c/ha, whereas the seed yield was 0.5–4.0 c/ha; the crude fat content was 1.15–3.37 and 1.62–9.81%, respectively. The fatty acid composition of seed lipids included caprylic, palmitic, stearic, oleic, linoleic, and α-linolenic acids. The highest content of polyunsaturated essential fatty acids represented by linoleic and α-linolenic acids was observed in oregano (86.74–87.27%), hyssop (76.41–85.96%), tulsi (85.67%), basil (72.52–80.72%), rue (78.04%), and blue fenugreek (72.96%). The specified yield and fatty acid composition provided a complete assessment of spices, herbs, and essential-oil plants with the prospect of their use as part of new functional products.