Sodium selenite regulates phenolics accumulation and tuber development of purple potatoes

It has been reported that selenium could increase nutritional components as carbohydrates, organic selenium, proteins and total amino acids of potatoes. However, there have been few reports on selenium-enriched purple potatoes as yet. In this study, the effects of selenium on phenolics and tuber development of purple potatoes were investigated. The main phenolic components in purple potatoes were separated and identified as chlorogenic acid, caffeic acid, malvidin-5-glu-3-dirhamnose-glucose, caffeic acid-acetylrhamnose ester and caffeic acid-prenylrhamnose ester. The total phenolics including malvidin-5-glu-3-dirhamnose-glucose could be directly quantified at 325 nm, with chlorogenic acid as a standard. The main phenolic components were significantly increased by selenium. Total tuber weight was significantly increased by selenium (R2 = 0.964, P = 0.002). In conclusion, selenium significantly increased phenolic components and promoted tuber formation of purple potatoes; in this sense, selenium-enriched purple potato should be a better functional food.