Antioxidant Capacity of Heirloom Delaway Kale Grown Across Sustainable Farming Systems

In response to the growth of commercialized farming practices, the Food and Agriculture Organization of the United Nations (FAO) has identified safe, efficient, and sustainable agriculture as a main priority of its strategic objectives. Several methods of farming that can enforce these aims lie in natural farming practices such as biodynamic agriculture and urban agriculture methods like aquaponics (AP) and hydroponics (HP). The purpose of this project was to analyze antioxidant content of kale grown across different sustainable food systems. This research project utilized oxygen radical absorbance capacity (ORAC) methods to analyze the total antioxidant capacity (TAC) of kale grown in conventional soil compared to several sustainable media; hydroponics, aquaponics, and biodynamic soil. We sought to analyze the difference in antioxidant content between conventional soil and soilless systems, AP and HP as well as differences between conventional soil and biodynamic soil kale. Biodynamic kale contained highest levels of antioxidant activity when compared with conventional soil. AP kale contained highest antioxidants when compared to AP and conventional soil systems. Though differences were small, research suggests antioxidant activity is boosted in sustainably farmed crops, such as biodynamics, secondary to pathogenic pressures that lead to the synthesis of antioxidants in the absence of commercial, conventional farming methods. Contrary to literature, HP kale produced the least antioxidant activity compared to all the other systems. Additional research is warranted to analyze the nutrient density of sustainable food systems compared to conventional methods.