Sprouting enhances phytonutrients and antioxidants in onion seeds

Abstract

Consumption of onion seed sprouts is getting popular for its flavour and texture. However, there is limited information on changes in the phytonutrients during sprouting of onion seed. The objective of this study was to determine the temporal variations in the phytonutrient content during the sprouting of onion seeds and to determine the appropriate time of sprouting for better nutrition. Seeds of three onion varieties (Bhima Red, Bhima Raj and Bhima Kiran) were germinated for different periods (5, 10 and 15 days). Changes in phytonutrients and antioxidant potential were analyzed. The highest flavonoids, thiosulfinates, and DPPH activity were observed in 10 days old sprouts, which were 38.78%, 160.71%, and 97.45% higher than seeds. Pyruvic acid, total phenols and ABTS activity was maximum in 15 days old sprouts, which was 682.69%, 189.03%, and 79.38% higher than seeds respectively. The sugars increased initially but declined with sprout age and the lowest levels were recorded in 15 days old sprouts. Sprouting enhanced the health-promoting phytonutrients and antioxidant activity of onion seeds and sprouts harvested at 10 and 15 days had a higher quantity of health-promoting phytonutrients.

Keywords

• Antioxidants
• Onion seed sprouts
• Phenol
• Sugar
• Superfoods
• Thiosulfinates