Sprouts contain higher total phenolics, total flavonoids, and antioxidant activity than seed in different thai varieties of mungbeans (Vigna Radiata L.)

It has been reported that mungbean seeds contain fat, protein, lecithin and amino acids, but the study of antioxidants and their activity in those seeds, particularly in comparison to the sprouts of Thai mungbean varieties, is rare. This research studied the antioxidants and antioxidant activity in seeds and sprouts of five Thai mungbean varieties (Vigna radiata L.), namely Chainat 36, Chainat 72, Chainat 84-1, M.T.S 1 and Kamphaengsaen 2. Total phenolics, total flavonoids, chlorophyll a, chlorophyll b, total chlorophyll and antioxidant activity (DPPH) in the seeds and sprouts were analyzed. The experiment protocols were arranged as a completely randomized design (CRD) (n=4). There was low variation of total phenolics, total flavonoids, chlorophyll a, chlorophyll b, total chlorophyll and DPPH radical scavenging in the seeds of all mungbean varieties. However, they increased sharply with germination. At Day 4, Chainat 36 sprouts were found to contain the highest total phenolics and total flavonoids (3,372.8 mg GAE/100g of DW and 6,808.6 mg QE/100g of DW, respectively), which were significantly higher than those in seeds and sprouts at other germination stages. The total phenolics in Chainat 36 also increased sharply by almost six-fold compared with the previous day, whereas it was three-fold in other varieties. The DPPH radical scavenging in the seeds of all varieties was low, but increased sharply during germination. The sprouts at Day 4 had significantly higher antioxidant activity than in seeds by almost 30-fold. At the same day, the highest DPPH radical scavenging was observed in the sprouts of M.T.S 1. In conclusion, antioxidants and their activity are low in mungbean seeds. After germinating, especially at Day 4, total phenolics and total flavonoids would rise significantly, especially in Chainat 36. This indicated that Thai mungbean sprouts are a good source of nutrition and health.