Effect of Kale Cultivation Conditions on Biosynthesis of Xanthophylls

Conditions of plant cultivation directly influence the chlorophyll and carotenoid pigments concentrations. The aim of investigations was the determination of lutein in kale (Brassica oleracea L. var. acephala) upon various cultivation conditions including: low and high temperature (overnight and daytime in the greenhouse the temperature was 12 ± 2C and in the laboratory the temperature was 22 ± 2C), lack of water (some plants were watered only one time weekly), saline stress (5% of sodium chloride added to irrigation water; watering two times weekly was applied), as well as UV radiation of plants by means of UV lamp (lambda = 254 nm; suitable to UVC solar radiation; duration 4 h per day). Three months old cuttings were taken and next mentioned cultivation conditions were applied during one month. Moreover, the outdoor cultivation of kale cuttings was performed. Qualitative and quantitative analyses of plant extracts were made by use of HPLC-UV-VIS-MS technique. Mean values for lutein accumulation as a function of dry mass (mg/g) in leaves of kale have been presented. Obtained results show maximum xantophylls (lutein) concentration occur in fully developed plant leaves of kale for red kale 2.04 ± 0.15 and green kale 1.10 ± 0.09 mg/g respectively.