Effect of ethylene on total phenolics, antioxidant activity, and the activity of metabolic enzymes in mung bean sprouts.

Mung bean sprouts are a well-known healthy food and their nutritional enhancement has become an important area of research due to the rapid expansion of the industry and their importance to human health. The purpose of this study was to investigate the effect of ethephon treatment at different concentrations on total phenolics metabolism and free radical scavenging-linked antioxidant activity. Mung bean sprouts treated with 100 mg/L of ethephon gave the highest total phenolics content of 0.594 mg/g FW, which was approximately 31 % higher than that of the control on the second day of germination. Total phenolics content in mung bean sprouts increased significantly by increasing glucose-6-phosphate dehydrogenase activity to resist oxidative stress caused by ethylene during early-stage germination. Total phenolics synthesis was greater than polymerization at this time. In contrast, polymerization of total phenolics gradually increased with the decrease in oxidative stress during late-stage germination. Total phenolics were polymerized to lignin because of the increase in guaiacol peroxidase activity. These results indicated that ethylene could improve the nutritional value of mung bean sprouts, and harmless stress factors could be used to enhance health-promoting compounds in the sprouts. [ABSTRACT FROM AUTHOR]