SodininkyStĖ ir darŽininkyStĖ 28(2)

Fig. 1. The antioxidant potential, as the ability to scavenge DPPHfree radicals of the young barely leaves, grown under different LEDillumination, extracts. Lighting treatments as in Table 1.1 pav. Jaunų miežių, išaugintų skirtingai apšvietus LED, lapų ekstraktųantioksidacinis potencialas, išreikštas kaip geba surišti laisvuosius DPPHradikalus. Apšvietimo deriniai tokie, kaip 1 lentelėje.The antioxidative properties of barely leaf extracts cohere with the results of analysisof phenolic compounds (Fig. 2). In the barely, grown under sole red (638 nm, L1)LED light, there was determined slightly more phenolic compounds in ‘Aura’ barleyleaves as compared to reference (R) HPS illumination; however, in ‘Luokė’ leaves,the differences were statistically insignificant. Illumination with red (638 nm) and blue(445 nm) light combination (L2) resulted in 32 % higher contents in ‘Aura’ leaves andin 61 % higher contents of phenolic compounds in ‘Luokė’ leaves. The illuminationwith red 638 nm, blue 445 nm and another red of 669 nm (L3) resulted in differentialconcentrations of phenolic compounds in the leaves of different barley varieties: it wasslightly reduced in ‘Aura’ barley; no significant differences from treatment L2 wereobserved in ‘Luokė‘ barley. In the treatment L4 the supplemental far red light had nosignificant effect on the contents of phenolics, as compared to treatment L3.The changes in vitamin C concentration were observed only in few spectral treatments(Fig. 3). Illumination with sole red light (treatment L1) resulted in somewhatsimilar vitamin C contents in the leaves of both barley leaf varieties. Supplementalblue light (L2) slightly promoted the accumulation of vitamin C, although the higherinput of red light flux in the total photosyntheticaly active flux, provided by red 669nm light (L3) reduced the vitamin C contents again. The supplementation of the redand blue light spectra with the far red light resulted in higher vitamin C contents: about50 % increase in ‘Aura’ leaves and almost double concentration in ‘Luokė‘ leaves, ascompared to illumination without far red light component (L3).156