Antioxidant capacity and contents of phenols, ascorbic acid, β-carotene and lycopene in lettuce/Antioksidativni kapacitet i sadrzaj fenola, askorbinske kiseline, β-karotena i likopena u salati

The antioxidant activity of three lettuce varieties (Lactuca sativa L) Emerald, Vera and Neva, cultivated in two kinds of protected spaces, a glasshouse and a plastic greenhouse, under controlled conditions, was determined. The content of antioxidant compounds: total phenols, flavonoids, L-ascorbic acid, β-carotene and lycopene, were determined in ethanolic extracts of the lettuce with spectrophotometric methods. The largest content of total phenols (78.98 ± 0.67 mg GAE/g of dry extract) was found in ethanolic extract of the lettuce variety Neva cultivated in a plastic greenhouse, whereas the largest content of flavonoids (35.45 ± 0.95 mg RU/g of dry extract) was displayed in the lettuce Emerald cultivated in a glasshouse. It was observed that the lettuce cultivated in the glasshouse contained a somewhat higher content of L-ascorbic acid than the lettuce same variety from plastic greenhouse. The content of lycopene in the examined lettuce is negligible, and the content of ^carotene is low. On the other hand, the high content of phenolic components causes favourable antioxidant properties found in all varieties of examined lettuce. Keywords: lettuce, antioxidant, phenolics, ascorbic acid, beta-carotene, lycopene. Odredena je antioksidativna aktivnost tri sorte salate (Lactuca sativa L.) Emerald, Vera i Neva gajene u dve vrste zasticenog prostora stakleniku i plasteniku pri kontrolisanim uslovima. Sadrzaji antioksidativnih komponenti: ukupni fenoli, flavonoidi, L-askorbinska kiselina, β-karoten i likopen, odredeni su u etanolskim ekstraktima salata spektrofotometrijskim metodama. Dobijeno je da najveci sadrzaj ukupnih fenola (78,98 ± 0,67 mg GAE/g suvog ekstrakta) ima etanolski ekstrakt salate sorte Neva gajene u plasteniku, dok salata Emerald gajena u stakleniku ima najveci sadrzaj flavonoida (35,45 ± 0,95 mg RU/g suvog ekstrakta). Zapazeno je da salate gajene u stakleniku imaju nesto veci sadrzaj L-askorbinske kiseline od salate istih sorti iz plastenika. Sadrzaj likopena u ispitivanim salatama je zanemarljiv, a β-karotena je nizak. S druge strane visok sadrzaj fenolnih komponenti uzrokuju dobre antioksidativne osobine nadene u svim sortama ispitivanih salata. Kljucne reci: Salata * Antioksidans * Fenoli * Askorbinska kiselina * Beta-karoten * Likopen Available online at the Journal website: