SodininkyStĖ ir darŽininkyStĖ 28(2)

SCIENTIFIC WORKS OF THE LITHUANIAN INSTITUTE OFHORTICULTURE AND LITHUANIAN UNIVERSITY OF AGRICULTURE.SODININKYSTĖ IR DARŽININKYSTĖ. 2009. 28(2).The effect of light quality on the antioxidativeproperties of green barely leavesAkvilė Urbonavičiūtė 1 , Giedrė Samuolienė 1 , Aušra Brazaitytė 1 ,Vytautas Ruzgas 2 , Gintarė Šabajevienė 1 , Kristina Šliogerytė 1 ,Jurga Sakalauskaitė 1 , Pavelas Duchovskis 1 , Artūras Žukauskas 31Lithuanian Institute of Horticulture, Kauno 30, LT-54333 Babtai, Kaunas distr.,Lithuania, e-mail a.urbonaviciute@lsdi.lt2Lithuanian University of Agriculture, Studentų g. 11, LT–53361 Akademija,Kaunas distr., Lithuania3Institute of Materials Science and Applied Research, Vilnius University,Saulėtekio al. 9–III, LT–10222 Vilnius, LithuaniaIn this study we evaluate the effect of lighting spectra, provided by light emitting diodes(LEDs), on the antioxidative properties of young barley seedlings, as the source of “greenfoods”. Lithuanian spring barley varieties ‘Luokė’ and ‘Aura’ were investigated. 7 day-oldseedlings, illuminated with the red (638, 669 nm), blue (445 nm) and far red (731 nm) light emittingdiode combinations were distinguished for different antioxidant potential, as free radicalscavenging ability, and uneven amounts of ascorbate and phenolic compounds. Antioxidativeproperties of barley variety ‘Luokė’ were found to be more sensitive to light spectral qualitythan ‘Aura’. LED treatments, except the lighting with sole red light, were superior in enhancingthe antioxidant potential of barley grass as compared to high-pressure sodium lamps. Red lightinhibited antioxidant activity and contents of vitamin C and phenolic compounds in barleyleaves, though the remarkable positive effect of supplemental blue light was observed. Theinclusion of other spectral components did not have such an effect.Key words: barley grass, light emitting diodes, phenolic compounds, radical scavengingactivity, vitamin C.Introduction. Human diet enriched with young parts of plants (so called “greenfoods”) can help to improve the balance of the human nutrient intake in a natural way.Green foods, providing nutrients like vitamins, proteins, minerals and antioxidants,are researched for numerous health benefits and already widely used in USA, EastAsian countries and Eastern Europe (Lee et al., 2003; Marsili et al., 2004; Paulickovaet al., 2006). The cereal grasses (young shoots of grain-bearing plants), includingalfalfa, barley, wheat, rye, oat, and kamut, are also beneficial. In their jointing stage,these plants contain peak concentrations of bioactive compounds and protectants,153