S08 - Session P2 - Efficient production of soybean isoflavones using a hydroponic system in a plant factory

Authors: Hansol Sim *, Ki-Ho Son, Kye Man Cho, Thi Kim Loan Nguyen

The establishment of the cultivation system is an important step for growing crops in a plant factory. Soybean ( Glycine max L.) is a high value-added crop and contains isoflavone that has health benefits such as anticancer, antioxidant, anti-inflammatory activities, and menopausal women. Health functional foods containing isoflavones in soybeans have highly marketable value. This study was conducted to establish a soybean hydroponic system in the plant factory for efficient soybean isoflavone production. Growth characteristics and isoflavone contents were analyzed to evaluate the soybean cultivation in a deep flow technique (DFT) system for about 4 weeks. As the result, total isoflavone contents in different parts of soybean plants analyzed by HPLC were 623.67 +- 7.72 µg g -1 in leaf, 328.94 +- 1.45 µg g -1 in the stem, and 703.22 +- 1.69 µg g -1 in the root. The productivity of isoflavones was estimated at 23.52 mg/layer/m 2 . This result suggests that it can produce a similar amount of 24~27 mg of soybean isoflavones as recommended dietary allowance (RDA) per day. In comparison with open fields, a plant factory allows the cultivation of plants on the multi-layer shelf, which enables to increase the yield and isoflavone content per unit area. Furthermore, the year-round production of soybean in plant factories can increase isoflavone content by about 3 times and 20 times per cycle and per year, respectively, compared to the open field. In conclusion, the hydroponic system conducted in this study was efficient for isoflavone production in all plant parts of soybean in the small area than in the open filed. Meanwhile, soybean sprouts are more efficient for the production of isoflavone contents than soybean plants. Our results also revealed that the pre-harvest UV-B treatment may improve isoflavone contents by upregulating the synthesis of isoflavone pathways.