Phytochemical Profiles and Antioxidant Activity of Sprouted Mung Bean and Sprouted Sunflower Seeds

Abstract

Mung beans and sunflowers are widely consumed as vegetables during their early stages of germination. Mung bean and sunflower sprouts contain beneficial substances suitable for the development of healthy food products. The purpose of this study was to compare the effects of germination on the phytochemical profiles and antioxidant activity of mung bean (Vigna radiata (L.) Wilczek) cultivar Chainat84-1 and sunflower (Helianthus annuus L.) cultivar Aquara6 hybrid sprouts, as well as to determine the optimal germination period for use as raw materials in the production of nutritious foods. The germinating seeds were evaluated at 0 – 6 days after imbibition (DAI). Moisture content, dry matter, ascorbic acid content, water-soluble protein content, and total phenolic content (TPC) were measured. Antioxidant activities were determined by using 2,2-diphenyl-l-picyrhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. Results showed that sprouting mung bean and sprouting sunflower seeds’ moisture content gradually increased, while dry matter decreased with time. Sprouting mung bean had the highest ascorbic acid content at 1 DAI (1.46 mg/100 g FW), whereas sprouting sunflower seeds had the highest ascorbic acid content at 3 DAI (0.58 mg/100 g FW). Water-soluble protein was highest in sprouting mung bean and sprouting sunflower seeds at 0 DAI of 9.81 and 5.16 mg/g FW, respectively. The highest TPC was found in sprouting mung bean at 4 DAI (46.82 mg GAE/g DW) and sprouting sunflower seeds at 0 DAI (134.70 mg GAE/g DW). Sprouting mung bean had the highest antioxidant activities in the DPPH assay at 4 DAI (IC50 of 2.07 mg/mL) and FRAP at 6 DAI was 2.93 mg GAE/g DW while sprouting sunflower seeds had the highest DPPH assay value at 0 DAI IC50 of 0.19, whereas at 1 and 2 DAI of 0.18 and 0.30 mg/mL, respectively while the highest FRAP value at 0 DAI was 11.62 mg GAE/g DW. The overall results indicated that mung beans and sunflower seeds at 0 DAI had the highest water-soluble protein, suitable for use as raw materials for the protein-based food products. Mung beans at 4 DAI and sunflower seeds at 0 DAI had the highest phenolic compounds and antioxidant activities that are suitable for producing health food products.