Nutrient and phytochemical composition of rocket and cabbage microgreens grown under varying potassium regimes

The growing demand for functional foods with specific nutritional profiles has led to increased interest in microgreens as customizable dietary sources. This study provides an in-depth nutritional and phytochemical characterization of wild rocket ( Diplotaxis tenuifolia L.) and black cabbage ( Brassica oleracea L.) microgreens cultivated under three potassium concentrations (0, 60, and 120 mg L⁻¹; K0, K60, K120). Mineral profiling revealed that potassium availability significantly influenced the elemental composition of black cabbage, while wild rocket maintained stable nutrient levels. A comprehensive volatile organic compound (VOC) analysis identified 37 compounds in rocket and 43 in cabbage, showcasing distinct phytochemical signatures. Moreover, nitrate, ammonium, and key quality parameters were quantified, revealing that potassium restriction can modulate nutritional composition without compromising sensory traits or safety. These findings underscore the potential of microgreens as adaptable food matrices for targeted nutritional interventions, especially in potassium-restricted diets. The species-specific metabolic responses observed further emphasize the importance of tailored cultivation strategies. • Low-potassium microgreens targeted the needs of persons with chronic kidney disease. • Wild rocket yield remained stable across K treatments. • Higher K in plant nutrient solution increased K and Na content in microgreens. • K reduction minimally impacted sensory quality, shelf life, and nutritional value. • VOC profiles showed species-specific effects; key aromas remained unaffected.