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Hodnotenie obsahu sekundárnych metabolitov a ďalších vybraných zložek v odrodách bazalky pravej pestovaných v skleníkových podmienkach
Muráriková, Andrea
The variety of Ocimum basilicum plays a primary role among culinary herbs in world trade. The main objective of this study was to determine yield and chemical composition of the essential oil, total phenolic and flavonoid content, total antioxidant capacity, L-ascorbic acid, crude fiber, nitrates, chlorophyll a, b, and carotenoids content. This work should be verified what influence had the variety, the seasonal, and the external factors affecting to said substances. Experiment was established in the greenhouse of the Faculty of Horticulture, Mendel University in Brno. The basil varieties, namely 'Ohře', 'Lettuce Leaf', 'Purple Opaal', 'Dark Green', 'Mammolo Genovese', 'Manes', and 'Red Rubin' were grown as a pot culture during the years 2014-2016. The essential oil were isolated by distillation and analysed by Gas Chromatography-Mass Spectrometry (GC-MS). The total phenolic content (TPC) was determinated spectrophotometrically according to Folin-Ciocalteau colorimetric method. Determinations of the total flavonoid content (TFC) were measured with the aluminium chloride colorimetric assay. The total antioxidant capacity (TAC) was evaluated by their ability to scavenging 2,2-diphenyl-1-picrylhydrazyl (DPPH) stable radicals. The ascorbic acid content was determined by High Performance Liquid Chromatography (HPLC). The crude ?ber content was determined by the enzymatic gravimetric method. The nitrates content was determined by Ion Selective Electrode (ISE). Chlorophyll a, b, and carotenoids were determinated spectrophototmetrically in the acetone extracts. The essential oil production was from 2.45 to 18.12 mg.kg-1 d. w., depending on variety and season. GC-MS analysis showed that the essential oil from 7 basil varieties consist of 41 components. Main constituents of the essential oil were methyleugenol (4.59-48.13 %), followed by methylchavicol (4.59-48.13 %), ß-linalool (0.43-33.25 %), eugenol (0.45-33.52 %), ?-bergamotene (0.07-13.40 %), eucalyptol (0.71-11.70 %), and ?-cadinene (0.24-8.90 %). The 'Purple Opaal', 'Dark Green', 'Mammolo Genovese', 'Mánes' and 'Red Rubin' varieties were identified as methyleugenol chemotypes while 'Ohře' varied according to the seasonal prevalence of linalool / methyleugenol. Variety 'Lettuce Leaf' was specific by the methylchavicol domination. The amount of TPC observed in methanol extracts were from 364.07 to 5606.43 mg GAE.100 g-1 d. w. TFC varied from 430.14-5979.69 mg CE.100 g-1 d. w. TAC were measured from 2.40 to 44.48 mM TE.100 g-1 d. w. L-ascorbic acid was ranged between 34.27-234.47 mg.kg-1 f. w. Content of crude fiber varied from 9.57 to 21.74 %. The mean levels of nitates were from 178.67-17918.21 mg.kg-1 f. w. The average contents of chlorophyll a, b, and carotenoids were 3.01-5.15, 1.26-2.65, and 0.65-1.53 mg.g-1 f. w., respectively. The influence of the variety and the season on the evaluated substances was significantly confirmed. The external factors on growth (temperature, relative humidity and solar irradiance) had an impact on all evaluated parameters with the exception of the contents of essential oils and TAC. For further cultivation of basil in pots, the most suitable are varieties 'Mánes' (excellent source of essential oil), 'Lettuce Leaf' and 'Red Rubin' (for their antioxidant capacity, and high contents of crude fiber). On the contrary, prone to the accumulation of nitrates were purple leaves varieties 'Purple Opaal' and 'Red Rubin'.
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