Effects Of Different Light Qualities On Quality And Antioxidant Properties Of Alfalfa (Medicago Sativa L.) Sprouts Vegetables

Alfalfa is a representative perennial legume herb of Medicago,which comes from the Near East Asia and Central Asia.There are thirteen species and one variety in our country.Because of its strong adaptability,high yield,excellent quality and long utilization years,it is honored as “the king of forages”.The effects of different light qualities on nutritional quality,medicinal value and antioxidant properties of alfalfa(Medicago sativa L.)sprouts were investigated with treatments of 2 h,4 h,6 h,8 h,10 h,12 h respectively in comparison with those of white,2 h,4 h,6 h,8 h,10 h,12 h UV-B and UV-A respectively in comparison with dark,and different light qualities of 24 h in comparison with those of dark.The results showed that green light had little effects on the quality of alfalfa;red light could improve the soluble sugar contents,which reached 1.90 % and increased extremely significantly by 43.9 %(P<0.05);blue light could improve the soluble protein contents,total anthocyanin contents,the phenylalanine ammonia-lyase(PAL)activity and the 1,1-diphenyl-2-picrylhydrazyl(DPPH)radical scavenging activity by 74.9%?450%?72.0%?10.3% respectively(P<0.05)compared with those of dark;white light could improve total phenolics and flavonoids by 46.2%?63.1% respectively(P<0.05)compared with those of dark;UV-B could improve the nutritional quality and antioxidant ability than UV-A;the soluble sugar contents of UV-B increased extremely significantly by 68.4 %,57.3 %,71.1 %,43.9 % after 4 h,6 h,8 h,10 h respectively(P<0.01);the soluble protein contents of UV-B increased extremely significantly by22.4 % after 4 h(P<0.01);the phenylalanine ammonia-lyase(PAL)activity of UV-B increased extremely significantly by 49.2 %,49.4 %,66.7 %,69.5 % after 4 h,6 h,8 h,10 h respectively(P<0.01);total phenolics,flavonoids and total anthocyanin contents of UV-B were extremely significantly improved: total phenolic contents increased by 5.3 % after 4 h(P<0.01);flavonoids contents increased by 4.6 % after 10h(P < 0.01);total anthocyanin contents increased by 44.4 %,81.8 %,63.7 % after 8 h,10 h,12 h respectively(P<0.01);moreover,the 1,1-diphenyl-2-picrylhydrazyl(DPPH)radical scavenging activity increased extremely significantly by 7.8 % after 12 h(P<0.01).These results revealed that white light,blue light,red light and UV-B radiation were effective in promoting quality and antioxidant properties of alfalfa.