Quality Characteristics and Antioxidant Activities of Lotus (Nelumbo nucifera Gaertn.) Sprouts Grown Under Different Conditions

Lotus (Nelumbo nucifera Gaertn.) is an economically important aquatic ornamental herb with multiple uses, including food, tea, natural pigments, and/or healthcare product. The objective of this study was to evaluate the physicochemical properties and antioxidant potential of lotus sprouts grown in three media: sprouting machine (LSSG), soil (LSSC), and mud (LSMC). The longest sprout was obtained in LSMC (4.79 and 26.79 ㎝) followed by LSSC (1.95 and 5.4 ㎝), and LSSG (0.60 and 2.85 ㎝) at 5 and 10 days, respectively. Higher amounts of total free amino acids were found in cotyledons (33.96, 21.45, and 38.90 ㎎/g) than in hypocotyls (15.77, 7.90, and 15.29 ㎎/g ) for LSSG, LSSC, and LSMC, respectively. The ratios of total essential to total non-essential amino acids were higher in hypocotyls (0.36, 0.31, and 0.46) than in cotyledons (0.34, 0.25, and 0.40), respectively. Similarly, the total polyphenol content of the hypocotyl of LSMC (50.33 ㎍ GAE/g) was the highest and that of the husk of LSSG (24.08 ㎍ GAE/g) was the lowest. Overall, the antioxidant potential of hypocotyl was higher than that of husk and cotyledon. The results indicated that the lotus sprouts grown in mud could be a good source of nutritional and natural antioxidants.