Enhanced Antioxidant Activity in Mung Bean Seedlings Grown under Slow Clinorotation

Initial growth studies in space have demonstrated microgravity has the potential to enhance antioxidant activity in fruit and vegetables. To examine whether a slow-rotating clinostat here on Earth can produce functional foods with enhanced antioxidant activity and related compounds, including carotenoids, phenolics and ascorbic acid, we grew mung bean seedlings under clinorotation (2 rpm) and measured the above components. The clinostat seedlings had higher antioxidant activity and accumulation of related compounds, compared to seedlings grown under normal gravity. To further explore the causes for these results, α-amylase activity and amount of starch in cotyledons were measured. Higher α-amylase activity and lower starch levels were observed in the cotyledons under clinorotation, suggesting the higher levels of sugars resulting from starch conversion were promoting the synthesis of antioxidant compounds and higher antioxidant activity in seedlings when grown under clinorotation. Our data indicate that a clinostat can enhance antioxidant activity in vegetables in the early developmental stage.