The aquaponics system is a sustainable way of integrating soilless crop farming and freshwater fish farming in a single system to reduce water consumption and pollution, increase food production per unit area, thereby rendering economic benefits to the farmer.
Leafy greens are the most highly cultured species because of their fast growth and relatively lower operation costs. High yield under suitable conditions and increased profitability are a major factor that makes leafy greens more attractive, compared to fruiting vegetables. Kale (Brassica oleracea L. var. acephala) is a green leafy vegetable in Brassicaceae family Initially evidenced in the eastern Mediterranean and Asia Minor regions. Kale has been widely studied for its nutritional highlights, health beneficial properties and value-added products of kale. However, the comparison of nutritional properties of kale produced in aquaponics and conventional systems are scarce.
The present study was carried out to determine the influence of the production system on biochemical composition and the total antioxidant capacity (TAC), total phenolics content (TPC), and total flavonoids content (TPC) of green leafy kale. The results demonstrated that leaves from aquaponic kale contained higher protein content, higher levels of polyphenols and has a higher antioxidant capacity. However, the fiber content and flavonoids were higher in the kale produced in soil agriculture system. This research suggest that kale produced in soilless aquaponics systems can hold high nutritional value compared with kale from traditional agriculture.
As consumers start to value sustainably produced products and become more aware of quality of food items vs quantity, research into nutrient density of sustainable crops can hold promising advantages for the market value and demand of sustainable agriculture.
Key words: aquaponics, kale, national value, crop chemical and biochemical composition.