Optimization of Extraction Technology and Antioxidant Activities in vitro of Pigments from Yunqing Hulless Barley

Purpose Our aim was to study the optimization of extraction technology and antioxidant activities in vitro of pigments from yunqing hulless barley.Method The optimal extraction technology of pigments from Yunqing hulless was investigated by quadratic general rotary design on the basis of single factor experiments. At the same time, the antioxidant activities of pigments were determined using 5 antioxidant activity assay systems in vitro.Results The results showed that the best extraction solvent for the pigments was 1% hydrochloric acid methanol (VHCl:Vmethanol=1.87:98.13).Also, the pigments were stability under acid condition and the maximum absorption wavelength was 528 nm. So the pigments may be anthocyanins. The best extraction conditions were as follows:extraction temperature was 45℃, the ratio of liquid to solid was 15:1 (mL:g), extraction time was 40 min. The pigments possessed good antioxidant activity. The DPPH free radical scavenging capacity was (10.86±2.13) μmol/g, ferric reducing/antioxidant capacity was (0.077±0.000 96) mmol/g, total antioxidant capacity was (101.48±8.97) μmol/g, reduction power was (42.48±14.34) μmol/g, H2O2 scavenging activity was (27.88±13.79) μmol/g.Conclusion The optimal extraction process of pigment of yunqing hulless barley is determined. The study provided the scientific basis for the development and utilization of the pigments.