Antioxidant capacity and enzymatic inhibitory of the bioactive compounds extracted from germinated mungbeans

Abstract

The purpose of this project is to investigate the effect of light on the phenolic compound accumulation in germinated mungbean seeds during 5 days of germination. Mungbean seeds were germinated in light and darkness conditions for 5 days. The extracts were obtained by using 80% (v/v) chilled ethanol solvent. Then the total phenolic content (TPC), total flavonoid content (TFC), antioxidant capacity and their enzymatic inhibitory potential were measured in every single day of germination. The Folin-Ciocalteu’s method was used to determine TPC and the DPPH (1,1-diphenyl-2-picrylhydrazyl radical) scavenging was used to determine antioxidants in the extracts. The non-germinated seeds contained the lowest amount of TPC and TFC as 831 ±153 μg FAE/g flour and 487 ± 48 μg RE/g flour, respectively and resulting in the weakest antioxidant activity (only 16.4 ± 0.3 %), alpha-amylase inhibitory activity (41.7 ± 0.4 %) and alpha glucosidase inhibition activity (35.4 ± 1.0 %). The TPC, TFC, antioxidant capacity and enzymatic inhibitory potential increased with the increasing of germination time. Using light for germination, 5-day-old sprouts had the higher contents of phenolics (5438 ± 199 μg FAE\g flour) and flavonoids (2016 ± 95 μg RE/g flour), possessed stronger antioxidant activity (87.4 ± 0.3 %), alpha-amylase inhibitory (69.0 ± 0.3 %) and alpha-glucosidase inhibitory (73.8 ± 1.1%). Germinated mungbeans at the fifth day in darkness condition had the highest TPC (8148 ± 154 μg FAE\g flour), TFC (2369 ± 82 μg RE/g flour), possessed the strongest antioxidant capacity (94.0 ± 0.5%), alpha-amylase inhibitory potential (76.1 ± 0.6%) and alpha-glucosidase inhibitory potential (79.8 ± 2.0 %). As a result, sprouted mungbean seed could increase the phenolic compound content and possess higher antioxidant capacity as well as higher potential of enzymatic inhibitory in comparison with non-germinated seeds. The longer germination time, the greater all the studied components are. Moreover, mungbeans sprouted in the darkness is better than in light condition. In conclusion, the extracts of sprouts could be a potential source of antioxidant and enzymatic inhibitory linked with health benefits. Keywords: Mungbean seeds. Sprouts. Total phenolics. Total flavonoids. Antioxidant and alpha-glucosidase inhibitory, alpha-amylase inhibitory.