engleski

Glucosinolates content and yield of brocolli cultivars in different growing periods

Among the functional food of plant origin, cruciferous vegetables are the abundant natural source of essential minerals, vitamins and phytochemicals. In broccoli (Brassica oleracea L. var. italica Plenck.), the concentration of glucosinolates and their bioactive hydrolysis products depend on the genetic, environmental and agronomic factors. Research with the aim to select promising hybrid broccoli cultivars, suitable for growing in agroecological conditions of northwestern Croatia, with high values of agronomic properties and bioactive compounds, was conducted during the spring-summer (SSGP) and summer-autumn growing period (SAGP). The field trials including 13 hybrid broccoli cultivars were laid out according to four-replication randomized complete block design. Planting dates were 19 April for the SSGP and 17 July 2007 for the SAGP, while harvest period started between 57 and 62 days after planting. During harvest period basic morphometric values of broccoli top inflorescence were determined. For analysis of total and individual glucosinolates content (HPLC system), samples of top inflorescence were freeze-dried. Mass of marketable top inflorescence during the SSGP ranged from 257 ('Agassi') to 403 g ('Parthenon') and from 321 ('Agassi') to 506 g ('Montop') in SAGP. The highest values of top inflorescence yield were achieved by cultivars: 'Parthenon' (1.33 kg•m-2) in SSGP and 'Montop' (1.5 kg•m-2) in SAGP. In both growing periods, prevailing indolic glucosinolates in all tested cultivars were glucobrassicin and 4-methoxyglucobrassicin. The highest glucobrassicin concentrations achieved 'Ironman' (13.2 μmol•g-1 DW) in SSGP and 'General' (9.5 μmol•g-1 DW) in SAGP, significantly higher than other cultivars. The main aliphatic glucosinolate was glucoraphanin. There were significant differences among cultivars in total glucosinolates concentration which ranged from 12 to 22.5 μmol•g-1 DW in SSGP and 5.4 to 15.5 μmol•g-1 DW in SAGP. 'General' and 'Marathon' achieved high values of agronomic and chemical properties in different environmental conditions.

Brassica oleracea L. var. italica; top inflorescence; bioactive compounds

nije evidentirano