Effects of different light conditions on nutrient components and antioxidant activity in maize during germination

【Objective】 This study aimed to explore the changes of nutrient components and antioxidant activities in germinated maize under different light conditions,so as to provide reference for the optimization of the optimal germination conditions of maize and the research and development of germinated maize products.【Method】 Xianghuiyu No.1 was used as the material to study the nutrient contents and the activities of superoxide dismutase(SOD),catalase(CAT) and peroxidase (POD) under different light conditions (24 h of light,12 h of darkness+12 h of light and 24 h of darkness) at 0, 1,3 and 5 d after germination,radicle length and germ length were measured at 1,3 and 5 d after germination,and the germination rate and vigor index were calculated, so as to analyze the correlation between germination indexes and nutrient components content as well as antioxidant activity.【Result】 With the extension of germination days,the contents of albumin,globulin,lysine,reducing sugar and the activities of three enzymes in maize were significantly increased(P<0.05, the same below),while the contents of total sugar and starch were significantly decreased. Compared with non-germinated grains,albumin content was significantly increased by 46.11% after 5 d under 12 h of darkness+12 h of light treatment. Except globulin content,the nutrient content and four germination indexes of 12 h dark+12 h light treatment were significantly higher than those of the other two treatments on the 5^th day of germination. The POD and SOD activities of 24 h light treatment were significantly higher than those of the other two treatments,while the CAT activities of 24 h dark treatment were the most significantly increased in the three treatments. Compared with the 1^st day of germination,the germination rate of 24 h of darkness,12 h darkness+12 h light and 24 h of light on the 5^th day of germination was significantly increased by 497.64%,137.69% and 263.48% respectively. The four germination indexes were extremely significantly (P<0.01) or significantly positively correlated with albumin,globulin,reducing sugar and lysine contents.【Conclusion】 The light condition of 12 h of darkness and 12 h of light is beneficial to the germination and nutrient components accumulation of maize. Plants activate enzyme systems to remove toxic substances caused by too much or too little light.